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t
ºTS26S THE DREDGING OPERATIONS OFF THE WEST COAST OF
CLNTRAL AMERICA TO THE GALAPAGOS, TO THE WEST COAST
OF MEXICO, AND IN THE GULF OF CALIFORNWA, IN CHARGE OF
ALEXANDER AGASSIZ, CARRIED ON BY THE U. S. FISH COMMIS-
SION STEAMER “ALBATROSS,” DURING 1891, LIEUT. COMMANDER i
Z. L. TANNER, U. S. N., COMMANDING.
XIV.
THE PELAGIC SCIIIZOPODA.
BY ARNOLD ORTMANN.
[Published by Permission of MARSHALL McDon ALD, U. S. Fish Commissioner.]
WITH ONE PLATE,
'E, MASS., U. S. A. :
FO R T H E M U S E U M.
SEPTEMBER, 1894.




























Bulletin of the Museum of Comparative Zoëlogy
AT HARVARD COLLEGE.
VOL. XXV. No. 8.
REPORTS ON THE DREDGING OPERATIONS OFF THE WEST COAST OF
CENTRAL AMERICA TO THE GALAPAGOS, TO THE WEST COAST
OF MEXICO, AND IN THE GULF OF CALIFORNIA, IN CHARGE OF
ALEXANDER AGASSIZ, CARRIED ON BY THE U. S. FISH COMMIS-
SION STEAMER “ALBATROSS,” DURING 1891, LIEUT. COMMANDER
Z. L. TANNER, U. S. N., COMMANDING.
XIV.
THE PELAGIC SCHIZOPODA.
BY ARNOLD ORTMANN.
[Published by Permission of MARSHALL McDon ALD, U. S. Fish Commissioner.]
WITH ONE PLATE.
CAMBRIDGE, MASS., U. S. A. :
PR IN T E D F O R T H E M U S E U M.
SEPTEMBER, 1894.
UN.VERSITY CF #...13ſ. 2RARIES
Museuſ].S.
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//22477-73%
No. 8. — Reports on the Dredging Operations off the West Coast of
Central America to the Galapagos, to the West Coast of Mewico,
and in the Gulf of California, in charge of ALEXANDER AGASSIZ,
carried on by the U. S. Fish Commission Steamer “Albatross,”
during 1891, LIEUT. COMMANDER Z. L. TANNER, U. S. N.,
Commanding.
[Published by Permission of MARSHALL McDonald, U. S. Fish Commissioner.]
XIV.
The Pelagic Schizopoda. By ARNOLD ORTMANN.
IEUPHAUSIACEA.
Thysanopoda agassizi, nov. Spec.
Form of body rather stout. Antero-lateral angles of the carapace rectan-
gular, rounded, and without a denticle. The lateral margins without denticles.
Rostral projection triangular, sharply pointed, longer than the eyes. Anterior
part of the carapace slightly keeled above. Third, fourth, and fifth segments
of the abdomen projecting posteriorly as acute dorsal spines. Sixth segment
somewhat longer than the preceding. Preanal spine small, simple. Eyes
moderate. The first joint of the antennular peduncle furnished at the distal
end with a dorsal cushion-like, densely hispid elevation. This elevation pro-
jects forward as an acute, somewhat outwardly directed, spine-like lappet, nearly
as long as the second joint: The outer anterior corner of the first joint bears a
smaller spine. The second joint projects forward as a spine-like lappet similar
to the first joint. The outer corner of the antennal scale bears a denticle.
Telson with 10 to 12 pairs of dorsal denticles, inner plate of the uropoda
shorter than the outer, the latter as long as the telson. Length, 19 mm.
This species is related by the long spine-like lappets of the antennulae to
Th. monacantha Ortmann, and by the hispid cushion of the first joint of the
antennulae to Th. obtusifrons Sars. But it may be recognized by the acute
rostrum, the absence of lateral denticles on the carapace, and the presence of
three dorsal abdominal spines.
VOL. XXV. — NO, 8.
100 BULLETIN OF THE
Stations of the “Albatross” 1 : —
3382. 200 fathoms.f. (Gulf of Panama, 60 miles from the 100 fathom
line.) One specimen.
3414. Surface to 200 fathoms.” (Between Galapagos and Acapulco, 350
miles from land.) One specimen.
Nyctiphanes australis G. O. SARs.
Challenger Schizopoda, 1885, p. 115, Pl. XX, Pl. XXI. figs. 1–7,
Stations of the “Albatross”: —
March 7, 1891. 8.30 p.m. Surface. (Gulf of Panama.)
Hyd. 2619. Surface to 1,000 fathoms, open part of net. (Off Galera Point.)
3388. Surface to 400 fathoms, open part of net; nothing in the closed
part towed at 400 fathoms. (Gulf of Panama, 25 miles
from land.)
3409. Surface. (Bindloe I., Galapagos.)
3435. Surface. (Gulf of California).
Stations of the “Survey’’ (between San Francisco and the Sandwich
Islands”) : —
52. Surface.
54. Surface. Long. 129° 5' W.; Lat. 35' 3' 30" N.
74. Surface. Long. 133° 56' 30" W.; Lat. 30°4' 30" N.
542. Surface, Long. 124°57' 30" W.; Lat. 35° 31' N. .
Geographical Distribution. The “Challenger” obtained this species in
the Australian seas, on the surface, at night (off East Moncoeur Isl., Bass Strait;
off Cape Howe; off Port Jackson). The above named stations show that it is
not restricted to the Australian Seas.
1 For a list of stations and chart of the route of the “Albatross,” see A. Agassiz,
Bull. M. C. Z., XXIII. No. 1, p. 4 and Pl. III., 1892.
f Indicates that the specimen came from the depth noted in the closed part of
the Tanner tow-net.
* Surface to 200 fathoms, or surface to arra, fathoms, hereafter indicates that the
specimen was brought up in the open part of the Tanner deep-sea tow-net, and that,
except as in the Gulf of California at no great distance from the coast in a closed
area, nothing was found in the closed part of the Tanner net when towed at sea at
300 fathoms or any greater depth, so that specimens brought up in the open part of
the net probably came from a depth of less than 300 fathoms. – A. Agassiz. See
Bull. M. C. Z., XXIII. No. 1, 1892.
* A number of pelagic Schizopods collected by the “Albatross" during the
survey of the route for a submarine cable between San Francisco and the Sand-
wich Islands have been examined by Dr. Ortmann, and are included in this report.
A. Agassiz.
MUSEUM OF COMPARATIVE ZoëLOGY. 101
Euphausia splendens DANA.
G. O. Sars, Challenger Schizopoda, 1885, p. 80, Pl. XIII. figs. 7–17.
The rostral margin is somewhat less produced than in Sars's Figure 15. The
structure of the antennulae is very characteristic ; the joints of the peduncle are
not provided with lobes, and from the dorsal face of the first joint springs a
fascicle of strong curved setae.
Survey stations (between San Francisco and the Sandwich Islands): —
540. Surface to 300 fathoms. Lat. 35° 19' 30" N.; Long. 125° 21' 30" W.
541. Surface to 300 fathoms. Lat. 35° 25' 30" N.; Long. 125°9' 30" W.
542. Surface. Lat. 35° 31' N. ; Long. 124°57' 30" W.
543. Surface. Lat. 35° 36' 30" N. ; Long. 124° 45' 30" W.
Geographical Distribution. Tropical and Southern Pacific; Southern
Atlantic.
Euphausia, mucronata G. O. SARS.
Challenger Schizopoda, 1885, p. 87, Pl. XV, figs. 9-11.
Stations of the “Albatross * : —
March 7, 1891. 8.30 p.m. Surface. (Gulf of Panama.)
Hyd. 2619. Surface to 300 fathoms, and surface to 1,000 fathoms. (Off
Galera Point).
3382. 200 fathoms.f. (Gulf of Panama.)
3388. Surface to 400 fathoms. (Gulf of Panama, 25 miles from land.)
3412. Surface. (Wenman I., Galapagos.) *
3414. Surface to 200 fathoms, and surface to 300 fathoms. (Between
Galapagos and Acapulco, 350 miles from land.)
13° 33' 30" N.; 97° 57' 30" W. 8 p. m. Surface. (Between Galapagos
and Acapulco, 250 miles S. E. of Acapulco.)
3416. Surface to 300 fathoms. (Near Acapulco.)
120 miles N. W. Acapulco. Surface to 175 fathoms.
Off Guaymas. Surface to 500 fathoms. (Gulf of California.)
Geographical Distribution. This species has been previously captured
only by the “Challenger”: South Pacific, off the coast of Chili, surface.
Euphausia pellucida DANA.
G. O. Sars, Challenger Schizopoda, 1885, p. 75, Pl. XI, XII.
Ortmann, Decap. u. Schizop. Plankton Exp. 1893, p. 11.
Stations of the “Albatross”: —
March 7, 1891. 8.30 p.m. Surface. (Gulf ºf Panama.)
3388. Surface to 400 fathoms. (Gulf of Panama, 28 miles from land.)
102 - BULLETIN OF THE
Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and
Galapagos). -
3409. Surface. (Bindloe I., Galapagos.)
3412. Surface. (Wenman I., Galapagos.)
3414. Surface to 100 fathoms." .
Surface to 200 fathoms. Between Galapagos and Acapulco,
Surface to 300 fathoms. 350 miles from land.
At 200 fathoms.
13° 33' 30" N.; 97° 57' 30" W. 8 p.m. Surface. (Between Galapagos
and Acapulco, 250 miles from land.)
3416. Surface to 300 fathoms. (Near Acapulco).
3434. Surface. (Gulf of California.)
50 miles south Guaymas. Surface to 700 fathoms.
Off Guaymas. Surface to 500 fathoms.
“Survey’’ stations (between San Francisco and the Sandwich Islands):—
165. Surface. Lat. 30° 23' N.; Long. 140° 26' 30" W.
542. Surface. Lat. 35° 31' N, ; Long. 124°57' 30" W.
543. Surface. Lat. 35° 36' 30" N.; Long. 124° 45' 30" W.
Geographical Distribution. Cosmopolitan : Arctic, North, Central, and
South Atlantic, Antarctic, South and Central Pacific, and Indian Oceans.
Euphausia diomedeae, nov. Spec.
Frontal part of the carapace produced as a broad triangular-pointed plate,
arched over the eyes, and covering their peduncles. Anterior part of carapace
with a sharp keel, the lateral margins with two denticles on each side. Seg-
ments of the abdomen smooth, without spines. Sixth segment longer than the
preceding. Preanal spine tridentate. Eyes of moderate size. Basal joint of
antennulae with a projecting leaflet above, divided into two lappets at the top.
Outer corner of the antennal scale unarmed. Subapical spines of the telson
finely denticulated at inner edge. Inner plate of uropoda a little longer than
outer, both shorter than the telson.
This species agrees with E. pellucida in most respects, but the rostral plate is
very different, being in E. pellucida acutely produced and not broadly arched
over the peduncles of the eyes. Perhaps E. diomedea, might be better re-
garded as a variety of E. pellucida.
Station of the “Albatross”: —
3409. Surface. (Bindloe I., Galapagos.) Two specimens, associated with
E. pellucida.
MUSEUM OF COMPARATIVE ZOOLOGY. 103
Euphausia, gibboides ORTMANN.
Decap, u, Schizop. Plankton Exp. 1898, p. 12, Pl. I, fig. 5.
Stations of the “Albatross”: —
Hyd. 2627. Surface to 1,770 fathoms. (Between Cape San Francisco and
Galapagos.) -
Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and
Galapagos, about 250 miles from the Galapagos.)
“Survey’’ station (between San Francisco and the Sandwich Islands): —
540. Surface to 300 fathoms. Lat. 35° 19' 30" N.; Long. 125° 21' 30" W.
Geographical Distribution. This species was obtained by the “Plankton
Expedition” in the tropical part of the Atlantic, between 0 and 500 meters.
©
Euphausia gracilis DANA.
G. O. Sars, Challenger Schizopoda, 1885, p. 89, Pl. XV. figs. 12–23.
Ortmann, Decap. u. Schiz. Plankton Exp. 1893, p. 13.
Stations of the “Albatross”: —
Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and
Galapagos, about 250 miles from the Galapagos.) º
3409. Surface. (Bindloe I., Galapagos.)
3412. Surface. (Wenman I., Galapagos)
Geographical Distribution. Central Atlantic; Tropical Pacific; Austra-
lian seas; Celebes Sea. Surface to about 1,000 meters.
Nematoscelis megalops G. O. SARs.
G. O. Sars, Chall. Schiz. 1885, p. 127, Pl. XXIII, figs. 5–10.
Ortmann, Plankton Exp., 1893, p. 15.
“Survey” stations (between San Francisco and the Sandwich Islands):—
540. Surface to 300 fathoms. Lat. 35° 19' 30" N.; Long. 125° 21' 30" W.
541. Surface to 300 fathoms. Lat. 35° 25' 30" N.; Long. 125°9' 30" W.
Geographical Distribution. North Atlantic ; Greenland, Nova Scotia,
British coasts ; Southern subtropical Atlantic.
Nematoscelis microps G. O. SARs.
G. O. Sars, Chall. Schiz. 1885, p. 131, Pl. XXV. figs. 1–4.
Ortmann, Plankton Exp. 1893, p. 16. •º-
The identification of this species is somewhat doubtful, since in none of the
specimens are the elongated legs preserved.
104 BULLETIN OF THE
Stations of the “Albatross'': —
3382. 200 fathoms.f. (Gulf of Panama, about 60 miles from the
100 fathom line.)
Hyd. 2619. Surface to 1,000 fathoms. (Off Galera Point.)
Hyd. 2627. Surface to 1,770 fathoms. (Between Cape San Francisco and
- Galapagos.)
Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and
Galapagos.)
3414. Surface to 200 fathoms, and surface to 300 fathoms. (Be-
tween Galapagos and Acapulco, about 250 miles from land.
3416. Surface to 300 fathoms. (Near Acapulco.)
50 miles South Guaymas. Surface to 700 fathoms.
Off Guaymas. Surface to 500 fathoms.
Geographical Distribution. North Atlantic ; Mediterranean; Central
Atlantic. Surface and 600–800 meters.
Nematoscelis tenella G. O. SARs.
G. O. Sars, Chall. Schiz. 1885, p. 133, Pl. XXV. figs, 5–7.
Ortmann, Plankton Exp. 1893, p. 16.
12° 34' N.; 97° 21' W. (Between Galapagos and Acapulco.)
Geographical Distribution. Central Atlantic ; Cape of Good Hope ;
Philippine Islands. Surface to 650 m.
Stylocheiron abbreviatum G. O. SARs.
G. O. Sars, Chall. Schiz. 1885, p. 147, Pl. XXVII, figs. 11–13.
Ortmann, Plankton Exp., 1893, p. 17.
Hyd. 2619. Surface to 300 fathoms. (Off Galera Point.)
Geographical Distribution. Mediterranean; Tropical Atlantic; Sub-
tropical Pacific (north of the Sandwich Islands). Surface to considerable
depths : 1,300–1,500 meters (Plankton Exp)., 600–1,200 meters (Chun).
Stylocheiron Suhmi G. O. SARS.
.G. O. Sars, Chall. Schiz., 1885, p. 142, Pl. XXVII, fig, 1–4.
Ortmann, Plankton Exp. 1893, p. 17.
In none of the specimens are the elongated legs preserved, but this species is
recognizable by the form of the eyes. -
Stations of the “Albatross'': —
3388. Surface to 400 fathoms (open part of net, nothing in closed part
at 400 fins.). (Gulf of Panama, 25 miles from land.)
MUSEUM OF COMPARATIVE ZoëLOGY. 105
Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and
Galapagos, about 250 miles from the Galapagos.) º
3414. Surface to 300 fathoms. (Between Galapagos and Acapulco,
350 miles from land.)
12° 34' N, 97° 21' W. (Between Galapagos and Acapulco, about 300 miles
S. E. of Acapulco). -
Geographical Distribution. Central Atlantic, Pacific; New Guinea and
Philippine Islands. Surface and 1,300–1,500 meters.
Stylocheiron flexipes ORTMANN.
Plankton Exp. 1893, p. 18, Pl. I. fig. 7.
Stations of the “Albatross'': – -
3382. 200 fathoms.f. (Gulf of Panama, about 60 miles from the
100 frn, line.) -
Hyd. 2627. Surface to 1,770 fathoms (open part of net). (Between Cape
San Francisco and Galapagos.)
Geographical Distribution. Central Atlantic, between surface and 500 m.
IMYSIDA.C.E.A.
BOREOMYSIS G. O. SARS.
Symopsis of the known Species.
an Eyes of the usual structure, with visual elements.
b. Eye-peduncles conical or fusiform, cornea moderately or not at all
expanded, not projecting laterally beyond the carapace.
ci Frontal margin produced to a sharp rostrum or pointed in the middle.
di No lateral frontal spines over the eyes.
el Eye-peduncle conical, cornea somewhat expanded. Rostrum well
- developed.
fi Eye-peduncle not prolonged as a tubercle over the cornea.
gi Rostrum bent upwards.
1. B. arctica (Kröyer). Greenland, Norway, 200–400 fathoms.
(Cf. G. O. Sars, Monogr. Norg. Mys. 3, 1879, p. 10,
Pl. XI.-XIII. * -
ga Rostrum perfectly horizontal.
2. B. nobilis G. O. Sars. Spitzbergen Sea, 459 fathoms. (Den
Norske Nordhavs Exp. Zool. Crust. 1885, p. 54, Pl. V.
figs. 22–28.) -
f, Eye-peduncle prolonged to a sharp tubercle over the cornea.
3. B. californica n. sp. Gulf of California.
106 BULLETIN OF THE
e, Eye-peduncle fusiform, cornéa very small, not expanded. Rostrum
represented by a small pointed projection.
4. B. microps G. O. Sars. South of Nova Scotia, 1,250 fathoms.
(Chall. Schizop. 1885, p. 184, Pl. XXXIII. figs. 7–10.)
d, A lateral frontal spine over each eye, therefore the frontal margin
three-spined. Eye-peduncle comical, cornea expanded.
5. B. tridens G. O. Sars. Norway, 300–400 fathoms. (Monogr.
Norg. Mysid. 3, 1879, p. 16, Pl. XIV.)
ca. Frontal margin obtusely rounded, without a rostral spine. Eye-
peduncles conical, cornea expanded.
6. B. obtusata G. O. Sars. North Pacific, 345 and 2,740 fathoms.
(Chall. Schizop. 1885, p. 182, Pl. XXIII. figs. 1-6.)
ba. Eye-peduncles constricted, very thin and cylindrical at the base. Cornea
greatly expanded, projecting laterally considerably beyond the carapace.
Frontal margin obtusely pointed, without a rostrum.
7. B. megalops G. O. Sars. Norway, 80–200 fathoms. (Monogr.
Norg. Mysid. 3, 1879, p. 18, Pl. XV., XVI.)
as Eyes imperfectly developed, calyciform, without pigment or visual elements.
8. B. scyphops G. O. Sars. Arctic and Antarctic, deep-sea.
(Nordhav's Exp. 1885, p. 56, Pl. VI. Chall. Schiz.
1885, p. 178, Pl. XXXII. figs. 10–20.)
Boreomysis californica, now. Spec.
This new species agrees so closely in almost every regard with B. arctica,
that it is useless to give a detailed description. The only difference I observe
is the peculiar character of the eye, whose cornea is somewhat less expanded,
and whose peduncle is prolonged over the cornea as a sharp conical tubercle.
The color of the cornea is pale brown, as in B. arctica (pigmento fulvescente).
It is somewhat doubtful whether this species belongs to the genus Boreo-
mysis or to a new genus. The rudimentary condition of the pleopods and the
want of male appendages to the antennulae show that the specimens are females,
but the incubatory lamellae are not developed. In the largest specimen I observe
at the base of the legs seven pairs of very little leaflets, which may be the seven
pairs of incubatory lamellae characteristic of the genus Boreomysis, and there-
fore I believe that this specimen, and also the two smaller ones, which do not
show these leaflets, are not fully developed females. On the other hand, in
case they are males, this species must be the representative of a new genus agree-
ing with the genera Mysidella and Heteromysis in the rudimentary condition
of the male pleopods, but differing in the structure of the other appendages
which are normally developed here.
50 miles south of Guaymas (Gulf of California). Surface to 700 fathoms.
(From the open part of net.) Three specimens.
MUSEUM OF COMPARATIVE ZOOLOGY. 107
Siriella, thompsoni (MILNE-EDwARDs).
G. O. Sars, Chall. Schiz. 1885, p. 205, Pl. XXVI, figs, 1–24.
Ortmann, Plankton Exp. 1893, p. 23.
“Survey stations” (between San Francisco and the Sandwich Islands): —
74. Surface. Lat. 30°4' 30" N.; Long. 133° 56' 30" W.
133. Surface (females only). Lat, 32° 35' N.; Long, 135° 3' W.
165. Surface (males only). Lat. 30° 23' N.; Long. 180° 26' 30" W.
Geographical Distribution. Tropical and subtropical seas, surface ;
Atlantic, Pacific, and Indian Oceans.
Siriella gracilis DANA.
Cf. G. O. Sars, Chall. Schizop. 1885, p. 209, Pl, XXXVI, fig. 25–28.
Galapagos: Charles Island, surface.
13° 33' 30" N.; 97° 57' 30" W. 8 p.m. Surface. (Between Galapagos
and Acapulco, about 250 miles S. E. of Acapulco.
Geographical Distribution. Restricted up to the present to the Tropical
Pacific. All the specimens were taken at the surface of the sea.
Euchaetomera typica. G. O. SARS, *
G. O. Sars, Chall. Schiz., 1885, p. 211, Pl. XXXVII, figs. 1–20.
Ortmann, Plankton Exp. 1893, p. 23.
Hyd, 2619. Surface to 300 fathoms. (Off Galera Point. Nothing in
closed part of net at 300 fathoms.)
Geographical Distribution. Tropical Atlantic and Northern subtropical
Pacific, surface.
108
OF THE
BULLETIN
OBSERVATIONS ON THE VERTICAL DISTRIBUTION OF SCHIZOPODA.
The following species were taken at the surface : —
Station.
March 7.
Gulf of Panama.
3409.
Time.
8.30 p.m.
7.24 p.m.
Off Brinloe Isl., Galapagos.
3412.
Off Wenman Isl.
13° 33' 30" N.;
97° 57. 30” W.
9 p.m.
, Galapagos.
8 p.m.
About 250 miles S. E. of Acapulco.
3434.
10.14 a. m.
Gulf of California, off Altata.
3435.
8.56 a. m.
Gulf of California, off Carmen Isl.
Nyctiphanes australis.
Euphausia mucronata.
Euphausia pellucida.
Nyctiphanes australis.
Euphausia pellucida.
Euphausia diomedeae.
Euphausia gracilis.
Euphausia mucronata.
Euphausia pellucida.
Euphausia gracilis.
Euphausia mucronata.
Euphausia pellucida.
Siriella gracilis.
Euphausia pellucida.
Nyctiphanes australis.
Number of
Specimens.
5
9
Many.
2
10
2
Many.
Many.
Many.
27
I2
Many.
I
I
8 jun.
In the first place one observes that all surface catches which contain a con-
siderable number of specimens were made at night, that is to say after sunset.
The catches at Stations 3434 and 3435, made in the forenoon, contain but few
specimens. In all the other catches made in the daytime the Schizopoda
are wanting. This fact shows again that the pelagic Schizopoda live at the
surface of the sea chiefly in the night, especially the species Nyctiphanes
australis, Euphausia mucronata, pellucida, and gracilis.
Other hauls made between surface and various depths contain the following
species taken in the open part of the Tanner net : —
Depth.
0–100 fathoms.
0–175 fathoms.
0–200 fathoms.
Station.
3414.
Euphausia pellucida.
350 miles S. E. of Acapulco.
120 miles N. W. Acapulco.
Hyd, 2628.
Euphausia mucronata.
Thysanopoda agassizi.
250 miles from the Galapagos.
3414.
350 miles S. E. of Acapulco.
Euphausia mucronata.
Euphausia pellucida.
Euphausia gibboidos.
Euphausia gracilis.
Nematoscelis microps.
Stylocheiron submi.
MUSEUM OF COMPARATIVE ZOOLOGY.
Station.
Hyd. 2619.
Off Galera Point.
3414.
350 miles S. E. of Acapulco.
3416.
25 miles S. E. of Acapulco.
Depth.
0–300 fathoms.”
3388.
Gulf of Panama, 25 miles from
land.
0–400 fathoms.”
0–500 fathoms. Off Guaymas, from open part
of net.
0–700 fathoms. 50 miles S. of Guaymas, from
open part of net.
Hyd. 2619.
Off Galera Point, from open
part of net.
Hyd. 2627.
Between Cape San Francisco
0–1,000 fathoms.
0–1,770 fathoms.
Euphausia mucronata.
Euphausia pellucida.
Nematoscelis microps.
Stylocheiron abbreviatum.
Stylocheiron submi.
Euchaetomera typica.
Nyctiphanes australis.
Euphausia mucronata.
Euphausia pellucida.
Stylocheiron submi.
Euphausia mucronata.
Euphausia pellucida.
Nematoscelis microps.
Euphausia pellucida,
Nematoscelis microps.
Nyctiphanes australis.
Euphausia mucronata.
Nematoscelis microps.
Euphausia gibboidos.
Nematoscelis microps.
109
and the Galapagos (nothing Stylocheiron flexipes.”
in closed part of net).
This series shows that the catches in the open part of the Tanner net to
depths of more than 300 fathoms do not contain more species than those
between 0 and 300 fathoms. It is also to be noted, that the hauls to 500
and more fathoms” contain a remarkably small number of species. All the
species obtained by the hauls extending from the surface to greater depths than
300 fathoms certainly occur, as is shown by other catches, in depths less than 300
fathoms, and it is very probable, that they occurred also in the same lesser depth
here; especially Euphausia mucronata, pellucida, and gracilis, Nematoscelis mi-
crops, and others.
From 200 fathoms were obtained in the closed part of the Tanner tow-net,
in the Gulf of Panama, about 60 miles from the 100 fathom line (Station
3382), Thysanopoda agassizi, 1 specimen, Euphausia mucronata, 6 specimens,
Nematoscelis microps, many specimens, Stylocheiron flecipes, 3 specimens.
1 It should be borne in mind that at no station at sea did the closed part of the
Tanner net bring up anything from a depth of 300 fathoms. – A. Agassiz.
2 Nothing in the closed part of the Tanner net when towed at 400 fathoms.
8 Is also found at Station 3382, in 200 fathoms, in the Gulf of Panama.
4 All of which come from the open part of the Tanner net, the closed part of the
net having at no station at sea brought up anything. — A. Agassiz.
110 BULLETIN OF THE
Very interesting is the Station 3414,1 at 11.14 a.m., 350 miles S. E. of Aca-
pulco. Here were obtained in the open part of the Tanner net: —
- Number of
- Speciulens,
0–100 fathoms. Euphausia pellucida. 3
0–200 fathoms. Thysanopoda agassizi. l
Euphausia mucronata. 2
Euphausia pellucida. 32
Nematoscelis microps. - l
0–300 fathoms (nothing in Euphausia mucromata. 4
the closed part of the Tanner Euphausia pellucida. 17
net towed at that depth 15 Nematoscelis microps. 5
minutes). - Stylocheiron submi. 2
Euphausia pellucida is the only species which comes in the daytime,
although in small numbers, near the surface of the sea, the other species swim-
ming at a greater depth. And, indeed, most of the E. pellucida are found by
day at a greater depth than 100 fathoms. On the other hand the catch from 0
to 300 fathoms contains no more specimens of this species than that from 0 to
200 fathoms. It is therefore very probable that most specimens of E.
pellucida swim during the daytime in depths from 100 to 200 fathoms. It
seems that the species E. mucronata and Nematoscelis microps are under
analogous conditions; they are wanting in the daytime in the zone of water
above 100 fathoms, but in the zone between 100 and 300 fathons they are
present.
Since other species are but rarely contained in the several catches, it is impos-
sible to get a good idea of their vertical distribution. But according to existing
data one may conclude that the most important and most abundant Schizopoda,
especially the species of the genus Euphausia, live in the daytime in a depth
from about 100 to 200 or 300 fathoms, and ascend at night to the surface.”
1 This locality, 350 miles from the nearest land, was the one selected for testing
the vertical distribution of the pelagic fauna by towing with the Tanner deep-sea
tow-net at depths of 100, 200, and 300 fathoms during the morning hours when the
surface species would naturally have sunk. See Bull. M. C. Z., Vol. XXIII.
No. 1, p. 52. — A. Agassiz.
2 This agrees with the well known paucity of the surface fauna during the bright
hours of the day. Nearly all pelagic material is collected more abundantly at
night. — A. Agassiz.
PELAG [C SCHIZOPODs.
"ALBATROSS" EX 1891
B.Meisel, lith.
A.Ortmann.del.

1.
MUSEUM OF COMPARATIVE ZoëLOGY. 111
*
IEXPLANATION OF PLATE.
Thysanopoda agassizi, nov. Spec., lateral view, #.
6& ( & frontal margin, eyes, antennulae, and antennal
scale, #.
Euphausia diomedeae, nov. spec., frontal margin, eyes, antennulae, and
antennal scale, 49. -
Boreomysis californica, nov, spec., a young female, lateral view, #.
(£ 6& antennula (b), *.
6& & 4 antenna (c), *.
€6 & & mandibula (d), 49.
(£ & &
first maxilla (e), 49.
second maxilla (f), 2.9.
maxilliped or first cormopod (g), epipodite
omitted, liº.
& 4 ($ second cormopod (h), 49.
& & & & third cormopod (i), '9.
& & & 8 uropod (w), *.
4 & { { telson (2), "ſº.
*-
*
*
*-a-
r
The Following Reports ARE IN PREPARAtion on the DREDGING
OPERATIONS of F THE WEst CoAst of CENTRAL AMERICA TO THE
GALAPAGOS, TO THE WEST COAST OF MExico, AND IN THE GULF of
CALIFoRNIA, IN CHARGE OF ALEXANDER AGASSIz, CARRIED ON BY
TILE U. S. FrSH CoMMIssion STEAMER “ALBATRoss,” DURING 1891,
LIEUT. CoMMANDER Z. L. TANNER, U. S. N., CoMMANDING.
A. AGASSIZ. II.1 General Sketch of the
Expedition of the “Albatross,” from
February to May, 1891.
A. AGASSIZ. The Pelagic Fauna.
A. AGASSIZ. The Deep-Sea Panamic Fauma.
A. AGASSIZ. I.” On Calamocrinus, a new
Stalked Crimoid from the Galapagos.
A. AGASSIZ. The Echini.
JAS. E. BENEDICT The Amnelids
R. BERGH. The Nudibranchs.
E. BRANDT. The Sagittae.
FC. BRANDT. The Thalassicolae.
C. CHUN. The Siphomophores.
C. CHUN. The Eyes of Deep-Sea Crustacea.
S. F. CLARKE, XI.11 The Hydroids.
W. H. DALL. The Mollusks,
C. B. DAVENPORT. The Bryozoa.
W. FAXON. VI.8 The Crustacea.
S. GARMAN. The Fishes.
W. GIESBRECHT. The Copepods.
A. GOñS. III 4 The Foraminifera.
H. J. HANSEN The Cirripeds and Isopods.
C. HARTLAUB. The Comatulae.
W. A. HERDMAN. The Ascidians.
S. J HICKSON. The Antipathids.
W. E. HOYLE. The Cephalopods
C. von KOCH. The Deep-Sea Corals.
C. A. KOFOID, Solenogaster.
R. von LENDENFELD. The Phosphores-
cent Organs of Fishes.
H. LUDWIG, IV.5 The Holothurians.
C. F. LüTKEN. The Ophiuridae.
E. L. MARK. The Actinarians.
GEO P. MERRILL. V.6 The Rocks of the
Galapagos. *
G. W. MüLLER. The Ostracods.
JOHN MURRAY. The Bottom Specimens.
A ORTMANN, XIV.12 The Schizopods.
ROBERT RIDGWAY. The Alcoholic Birds
P. SCHIEMENZ The Pteropods and Het-
eropods. Qº
W. SCHIMKéWITSCH. VIII.8
nogomidae.
S. H. SCUDDER. VII.7 The Orthoptera of
the Galapagos.
W PERCY SLADEN The Starfishes.
L. STEJNEGER. The Reptiles.
TH. STUDER. X 10 The Alcyonarians.
C, H. TOWNSEND The Birds of Cocos
Island.
M. P. A. TRAüTSTEDT. The Salpidae and
Doliolidae.
E. P. WAN DUZEE. The Halobatidae.
H. B. WARD. The Sipunculoids.
H. W. WILSON. The Sponges.
W. McM. WOODWORTH. IX.9
marians.
The Pyc-
The Pla-
1 Bull. M. C. Z., Vol. XXI., No. 4, June, 1891, 16 pp. ; and Vol. XXIII, No 1, February, 1892,
89 pp , 22 Plates.
[Zool Anzeig, No. 420, 1893 l
2 Mem. M. C. Z., Vol. XVII., No. 2, January, 1892, 95 pp, 32 Plates.
3 Bull. M. C. Z, Vol. XXIV, No. 7, August, 1893, 72 pp.
4 Bull. M. C. Z, Vol. XXIII., No. 5, December, 1892, 4 pp., 1 Plate.
5 Bull. M. C. Z., Vol. XXIV., No 4, June, 1893, 10 pp.
G Bull M. C. Z, Vol XVI., No. 13, July, 1893, 3 pp
7 Bull. M. C. z., Vol. XXV, No 1, September, 1893, 25 pp
8 Bull M C Z., Vol. XXV, No. 2, December, 1893, 17 pp., 2 Plates.
9 Bull. M. C. z., Vol. XXV., No. 4, January, 1894, 4 pp., 1 Plate
10 Bull. M. C. Z., Vol. XXV., No. 5, February, 1894, 17 pp.
11 Bull. M. C. Z, Vol. XXV No. 6, February, 1894, 7 pp, 5 Plates
12 Bull, M. C. Z., Vol. XXV No. 8, September, 1894, 18 pp , 1 Plate.
PUBLICATIONs
* * or the ,
MUSEUM OF COMPARATIVE ZOöLOGY
AT HARVARD COLLEGE,
^s.
There have been published of the BULLETINs Wols. I. to XXIV. ;
of the Memoirs, Vols. I. to XVI.
Vols. XVI. and XXV. of the BULLETIN, and Vols. XI. and xVII.
of the MEMOIRS are now in course of publication.
The BULLETIN and MEMOIRs are devoted to the publication of
original work by the Professors and Assistants of the Museum, of
investigations carried on by students and others in the different
Laboratories of Natural History, and of work by specialists based
upon the Museum Collections.
The following publications are in preparation : —
Reports on the Results of Dredging Operations from 1877 to 1880, in charge of
Alexander Agassiz, by the U. S. Coast Survey Steamer “Blake,” Lieut
Commander C. D. Sigsbee, U. S. N., and Commander J. R. Bartlett, U.S.N.,
Commanding
Reports on the Results of the Expedition of 1891 of the U. S. Fish Commission
Steamer “ Albatross,” Lieut. Commander Z. L Tanner, U S N., Com-
manding, in charge of Alexander Agassiz
Contributions from the Zoological Laboratory, in charge of Professor E. L.
Mark.
Contributions from the Geological Laboratory, in charge of Professor N. S.
Shaler.
Contributions from the Petrographical Laboratory, in charge of Professor
J Eliot Wolff.
Subscriptions for the publications of the Museum will be received
On the following terms : —
For the BULLETIN, $5.00 per volume, payable in advance.
For the MEMOIRs, $8.00 { { { { (, ,
These publications are issued in numbers at irregular inter-
vals ; one volume of the Pulletin (8vo) and half a volume of the
Memoirs (4to) usually appear annually.
Each number of the Bulletin and of the Memoirs is also sold
separately, and a price list of the publications of the Museum will
be sent on application to the Director of the Museum of Compara-
tive Zoology, Cambridge, Mass.
ALEXANDER AG ASSIZ, Director.