CORNELL UNIVERSITY

 

The
WILLIAM D. SARGENT
Collection

* A Gift to the Laboratory of Ornithology «+

 

 

 

 

 

 
WIR. IAM. DUNLAP SARGENT

1g4o

 

(CORNELL
LAB of ORNITHOLOGY

 

 

LIBRARY

at Sapsucker Woods
>

Illustration of Bank Swallow by Louis Agassiz Fuertes

 

 

 
 

 

DEPARTMENT oF THE INTERIOR.

 

OUTLINES

OF A

“9,

| NATURAL ARRANGEMENT
b

rrr at,

 

-FALCONIDS.

ROBERT RIDGWAY.

 

[EXTRACTED FROM BULLETIN OF THE UNITED STATES GEOLOGICAL AND.
GEOGRAPHICAL SURVEY OF THE TERRITORIES, No. 4, SECOND SERIES,}

 

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
June 10, 1875. ~.

 

 

 

 

 

 
SARGENT
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6796
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LARSON Ye Sef yee SIV
a hematin ae seaeiemaal
 

By Rosert Riweway.

[Read before the Philosophical Society of Washington, April, 1875.]

Until very recently, ile Birds of Prey have been classified entirely
according to their external characters, the primary division being into
three so-called families, as‘ follows: (1) Vulturide, or vultures, char-
acterized by their naked heads, sluggish habits, and filthy food 3 (2)
Falconide, or falcons, hawks, eagles, and other diurnal birds of prey,
distinguished by their feathered head and predatory nature; and (3)
Strigide, or owls, known from both the preceding -by having the eyes
directed forward, instdad.of laterally, and by being nocturnal.

Notwithstanding the fact that occasional genera constituted transi-
tional forms intermediate between two “ families”,* the above classifi-
cation was adopted almost universally until the year 1867, when Pro-
fessor Huxley clearly demonstrated} .thak&the so-called family Velturida
had no existence in fact, it being:an unnafiural associatiomof. embers
of two very distinct families, viz, the Cathartide, or AM@erican vultures,
on the one hand, and a group of the Falconide (the Old-World vultures)
on the other. Besides the announcement of the above important dis-
covery, Professor Huxley also proved that the secretary bird (Serpenta-
rius reptilivorus), previously included among the alconide, was in real-
ity the sole representative of a very distinct family, which he named
“ Gypogeranide.”

To sum up the important results of Professor Huxley’s studies of the
osteology of the rapterial birds, they are briefly as follows: (1) The de-
molition of the old so-called family Vulturide, the typical members of
which were referred to the Falconide ; (2) the recognition of a separate
family, Cathartide, to accommodate the aberrant ones ; and (3) the re-
moval of Serpentarius from the Falconide and its establishment as a
distinct family, “Gypogeranide.” The families of diurnal Raptores, ac-
cording to Huxley’s views, then were as follows: (1) Cathartidw (Amer-
ican vultures) ; (2) Gypaétide (—Falconide, hawks, S&c., including the
Old-World vultures) ; and (3) Gypogeranidw (=-Serpentariide, the secre-
tary bird).

After a very careful consideration of all that relates to the principles
of a naturai classification, I find every reason for adopting, without
hesitation, Mr. Huxley’s conclusions. t

 

* Examples of these perplexing ‘‘ intermediate” forms are the genera Gypattus and Poly-
borus, among the Falconide, which combine ‘‘vulturine” and “ falconine”’ characteristics
of habits and external appearance; while among the Strigide the genus Surnia is strictly
diurnal, and its appearance decidedly hawk-like. The falconine genus Circus, on the other
hand, has a distinct facial ruff and other characteristics belonging chiefly to the owls.
These cases were very embarrassing to the followers of the old classification, and by different
authors were shifted from one family to the other.

t Proceedings of the Zoédlogical Society of London, 1867, pp. 440, 443, 462, 465. ;

+I cannot follow, however, in substituting the name Gypaétide for the old term Falconide,
which in its former signification is sufficiently comprehensive to justity its continued use
as the proper name for this family; the term Gypogeranide is equally objectionable, since
Gypogeranus (Illiger, 1811) is antedated by Serpentarius (Cuvier, 1798), in consequence
of which Serpentartide (Selys, 1842), as adopted by Gray (Hand List, 1869, p. 38), is
preferable.
2

A fifth family, the Cariamide, or Cariamas, is quite nearly related to
those mentioned, aud has by some authors been even included among
the Falconide ; but the degree of its relationship by no means justifies
that view of its affinity. The families Strigidw, Falconide, Cathartide,
Serpentariide, and Cariamide may possibly be eventually combined to
form an order; but whether this association would be a natural one is an
undecided question, beyond the province of this paper.

Having defined the limits of the family Falconide, it now remains to
treat of this alone; the subdivisions of the family being the subject of
discussion. j

To the present time, the Falconide have been divided into a greater
or less number of so-called “ subfamilies”, the number varying accord-
ing to the author; those founditig their classification on purely exter-
nal characters finding it necessary to adopt a great many, and those
relying upon the anatomical characters carefully avoiding any sub-
division at all.*

To review in this connection all the classifications of the family which
have been proposed up to the present time would require far more space
than the limits of this memoir will allow; each author, while following
a generally-recognized plan, having his own peculiar views regarding
certain details of arrangement. It will, therefore, suffice for the pres-
ent to give a mere outline of this generally-adopted plan, and supple-
ment it by the modified systefns of our latest and best authorities.

The “ subfamélies” usually recognized are the following: (1) “ Faleo-
nine”, (2) “Milvine”, (3) “Accipitrine”, (4) “Circine”, (5) “Buteonine”,
(6) “Aquiline”, and (7) ‘ Polyborine.” Some authors add “ Circetine”
and “Pandionine” ; while previous to the important discovery, made
by Professor Huxley, regarding the vultures before alluded to, this
supposed family was divided into the so-called subfamilies, (1) “ Vaul-
turine”, (2) * Gypine”, (3) “ Neophronine”, (4) “Gypaétine”, and (5) “ Gy-
pohieracine”,—some authors grouping two or more of these in one,
others recognizing all. They are all, of course, typical Falconida, thus
making a total of fourteen subfamilies into which this family has been
divided, when there are in reality but two.

Mr. George Robert Gray, in his “Hand List of Birds in the Brit-
ish Museum”,{ divides the Falconide into seven so-called subfamilies,
as follows: (1) Polyborinw, LaFR., 1839 (=Polybori of the subfamily
Falconine); (2) “ Buteonine, SWAINS., 1837”; (3) *“Aquiline, SWAINS.,
1837”; (including Pandion !); (4) ‘\Falconinw, SwAIns., 1837” (including
Harpagus!); (5) “‘ Milwine, Bonar., 1838”; (6) “Accipitrine, SWAINS.,
1837” (including Herpetotheres and Micrastur, both groups of the sub-
family Falconidee) and (7) “ Circine, Br.”

Messrs. Philip Lutley Sclater and Osbert Salvin, in their “ Nomenela-
tor Avium Neotropicalium”,; divide the American members of the fam-
ily into the following “subtamilies”: (1) “Pandionine”, (2) Circinw”,
(3) “Buteonine”, (4) “Accipitrine”, (5) “Falconine,” (6) “Milvine MT)
“‘Herpetotherinw”, and (8) “Polyborine.”

Mr. R. Bowdler Sharpe, in his recently-published great-work upon
the diurnal “Accipitres”,§ employs a singularly inconsistent classification,

*This has, perhaps, been mainly due, not to the difficulty of finding sufficiently good char-

acters, but to the fact that the conclusions arrived at wer i S
Tiehed' by ae were so opposed to views long estab-

t+London, 1869, (vol. I).
{ London, 1873, pp. 118-123.

§ Catalogue of the Accipitres, or diurnal birds of prey, , i riti
Mucie Laie Fain ise rds of prey, in the collection of the British
3

which can only be considered a decided retrograde from, instead of an
improvement upon, the better classifications which preceded it. In the
first place, the genus Pandion is made to form a “ suborder ”—Pandiones !
This would not be so bad, all things considered, were it not that the
genus Polioaétus is included in this so-called “suborder”, the latter
being a very near relative, probably a subgenus, of Haliaétus, one of
the group Buteones‘of the subfamily Buteonine, and not at all allied to
Pandion (group Pandiones of Buteoninc), though it represents that genus
in its group; that is, is analogous, but not affined toit. In the next
place, Serpentarius (= family Serpentariide) and Cariama (= family
Cariamide) are placed in the “subfamily ” Polyborine! The subfami-
lies which Mr. Sharpe recognizes are the following: (1) Polyborine, (2)
Accipitrine, (3) Buteonine, (4) Aquiline, and (5) Falconine.

In this connection, it may be well to call attention to the importance

of distinguishing between evidences of affinity and those of mere anal-
ogy in the birds of this family. Certain types of teleological modifi-
cations are repeated in members of different subfamilies, and in different
groups of one subfamily, to such a degree of perfection, that, if we were
to follow external appearance only, we would not hesitate to place
them near together in' a systematic arrangement. This is what has
led to such confusion and such utterly unsatisfactory results as have
characterized most attempts at a natural classification. Among the
more prominent instances of analogy between members of different
groups or subfamilies, or even different families, the following may be
mentioned : The family Cathartide is reproduced in the vultures of the
Old World (vulturine series, group Buteones, subfamily Buteoninw, fam-
ily Falconide); the Gypogeranide and Cariamide, in a less degree, by
Polyboroides and. Geranospizias (Buteones); the Strigide, in a very slight
degree, by Circus (Buteones, Buteonine), Micrastur (Micrastures, Fal-
conine), and Pandion (Pandiones, Buteonine).* The Falcones are rep-
‘resented in the Buteonine by Ictinia and Harpagus (Buteones); also
by Baza (Pernes); oneof the Polybori (Ibycter) by Rostrhamus (Buteones) ;
the Micrastures are repeated in the genera Circus and Nisust (Buteones),
and Herpetotheres very nearly imitated by Circaétus (Buteones). Taking
the Buteonine alone, the Pandiones are mimicked by certain Haliacti
(Buteones); Certain Pernes (Elanoid es) by Milvus and Nauclerus (Buteones) ;
and others of the same group (Baza and Aviceda) by Harpagus and
Letinia.

In three widely-distinct “series” of generain the group Buteones, we
find a very peculiar type of modification, viz, the excessive abbreviation
of the outer toe. This occurs only in Heteropus (an “ aquiline” form,
with densely-feathered tarsus), Polyboroides (a long-1 egged terrestrial
form, with reticulated tarsus), and Geranorpozias (similar to the last, but
with scutelate tarsus); these latter two differ from the first in being
of terrestrial habits, and in a very remarkable teleological modification
of the tibio-tarsal joint, whereby it can be bent with ease in both direc-
tions.

The following tabular arrangement expresses the equivalents of the
two subfamilies and several groups, adopted in this memoir in the
numerous “subfamilies,” or “families” of leading authorities, and suc-

 

* Circus resembles the owls merely in the possession of a distinct facial ruff and large ear-
aperture; Micrastur, in the same respects, and also in decomposed downy edges to tle
inner webs of the primaries, the rounded, concave wing, as well as in the dimorphic plum-
age of some of the species (‘‘rufescent” and “ gray” phases”); Pandion, in having
the outer toe reversible and in lacking after-shafts to the feathers. : ;

+ In general form, Micrastur exactly repeats the genus Nisus, and has, besides, the facial
ruff of the genus Circus.
4

ceeding it a series of diagnoses explaining the reasons which justify
such a classification :*

 

 

 

 

a
2
a
-
RE
a Ripeway. SHARPE, Sci. & SALv. SUNDEVALL }
3 & (‘'Groups.”’) (‘Subfamilies.”) ('Subfamilies,”) (‘'‘Families.”)
ma
ui
3
R
8 Falcones. Falconine. Falconine. ‘Falconine.
3 Polybori. Polyborine. , Polyborinz. Polyborinz.
8 Micrastures. Accipitrine (pt.). Accipitrine (pt.). Circaétine (pt.).
e Herpetotheres. Aquilinze (pt.). Herpetotherinz. Circaétine (pt.).
{| Pandiones. Pandiones. 2 Pandionine. Circaétinz (pt.).
. Aquilinz (pt.), i obra
8 Pernes, i Falconinz (pt.), Milvine (pt.). Circaétinz (pt.).
3 Milvinz (pt.). a
e4 ( Accipitrine (pt.), ( Falconine (pt.), { Falconine (pt.),
£ Buteoninz (pt.), Milvinz (pt.), Circaétine (pt.),
fa) Buteones, Aquilinz (pt.), | Sirs, Aquiline (pt.),
Falconinz (pt.), Accipitrine (pt.). Gypaétinz,
{ (Vulturidze (pt.). Vulturine, >
Haliaétine (pt.).

 

 

 

 

 

1 Férnyad anordning av Dagrovfoglarna (Dispositio nova Accipitrum Hemeroharpagorum), Ofersigt af
Kongl. Vetenskaps Ak«demiens Fordhandlingar 1874, No.2. Stockholm.
u_? ' Suborder.”

A.—Scapular process of the coracoid produced forward so as to meet
the clavicle.t_ Nasal bones almost completely ossified, the nostril
being a small, usually circular, opening, with a conspicuous, usually
central,bony tubercle.{ Inferior surface of thesupramaxillary with
a prominent median angular ridge. Superciliary process of the
lachrymal consisting of a single piece.§....Subfamily Falconine.

B.—Scapular process of the coracoid not produced forward, but separated
from the clavicle by a wide interval.|| Nasal bones very incom-
pletely ossified, the nostrils large, without bony tubercle, and
frequently with an incomplete septum. Inferior surface of the
supramaxillary without median ridge. Superciliary process of
the lachrymal usually consisting of two pieces, joined by a cartil-
aginous hinge.** ...... 02.2.2... 20.0005. .Subfamily Buteonine.

 

* It is proper to explain here that the key to the leading character was furnished by Pro-
fessor Huxley in the paper before referred to (p. 464), in the following words: ‘‘The scap-
ular process of the coracoid sometimes is * [ * e.g., inthe Falcons proper, and in Polyborus]
and sometimes is not produced to the clavicle’—having reference to the family Falconide.
Following up this clew by examining the coracoid apparatus of every genus available, I was
surprised to find it to be a character which separated trenchantly not only the ‘‘ Falcons
proper” (—Falcones) and Polyborus, but also all the genera related to the latter, besides Mi-
crastur and Herpetotheres, from all other Falconide.

+See Plate XI, Figs. 1-4, ;

{Except in Micrastur. (See Plate XII, Fig. 4.)

§ See Plate XIII, Figs, 1-4.

|| See Plate XI, Figs, 5-11.

1 In Fig. 6, Plate XII, the tomium of the supramaxillary is so deeply sinuated as to
Allow the middle portion of the under surface to be seen from the side; but this has no anal-
ogy to the raised median ridge of the falconine forms.

Me si tions ae ve pie ( ee ee Pernes (Elanoides, Cymindis, Regerhi-
nus, Aviceda, Baza, &c.), in which this bone much resemble yf th hori i
in Figs, 6 and 7, Plate X1IL s that of the Polybori, as shown
er)
Subfamily FALCONINA.

The term Falconinw has been restricted in most previous arrange-
ments to the true falcons (= Falcones of the present system), but in view
of its being a subfamily-name it becomes necessary to make it cover all
the forms allied to these by subfamily-characters ; hence the wider sig-
nification given it here.

The subfamily Falconine is composed -of four well-defined groups,
the Falcones, Polybori, Micrastures, and Herpetotheres, which are distin-
guished as follows:

A.—Posterior toe abbreviated, very much shorter than the lateral pair ;
tarsi and toes covered with small hexagonal scales, larger in
front.

a. Nostril a small, round, or oblique opening, with a bony rimmed

margin and central tubercle. (Plate XII, Figs. 1-3.)

1. Superior tomium with a conspicuous tooth, and inferior
tomium with a corresponding notch. (Plate XII, Fig. 2,
and Plate XV, Fig. 1.) Superciliary process of the lach-
rymal elongated, narrow, reaching nearly across the orbit.
(Pl. XIII, Fig. 2.) Posterior margin of the sternum nearly
even, with a pair of large oval foramina. One or two
outer primaries with their inner webs emarginated near

their tips. (Plate XVIT, Figs. 1 and 2.)..Group 1, Falcones. ~

2. Tomia without tooth or notch.*

Superciliary process of the lachrymal abbreviated, reaching
only half-way across the orbit. (Plate XIII, Fig.1.) Pos-
terior margin of the sternum with a pair of deep indenta-
tions. Three or more outer primaries with their inner
webs sinuated near the middle portion. (Plate XVII,
Figs. 3 and 4.)...... 2.2... .0e 2s eeeee Group 2, Polybori.

b. Nostril a large opening without bony-rimmed margin or central

tubercie. (Plate XII, Fig. 4.)

3. Superciliary process of the lachrymal elongated, broad, ex-
tending nearly across the orbit. (Plate XIII, Fig..4.)
Tomia without tooth or notch. (Plate XII, Fig. 4, and
Plate XIV, Fig. 2.) Posterior margin of the sternum as in
Falcones. Four or more outer primaries with inner webs
sinuated near the middle portion...Group 3, Micrastures.

B.—Posterior toe elongated, almost equal to the lateral pair. Tarsi and
toes covered uniformly with thin, rough, imbricated scales.

4, Tomia without tooth or notch. (Plate XII, Fig. 3, and Plate
XIV, Fig. 1.) Nostril as in Falcones and Polybori. Su-
perciliary process of the lachrymal elongated, very broad,
reaching nearly across the orbit. (Plate XIII, Fig. 3.)
Posterior margin of the sternum nearly even, entire, and
withont foramina. Primaries as in Polybori_ and Micras-
TUNES caccdssRioae ow acia cae ae eee Group 4, Herpetotheres ,

The pterylography of the members of this subfamily affords some
very important diagnostic characters. From the descriptions given
by Nitzscht (pp. 55-57), the following arrangement may be tabulated,

 

* Though faint indications of these are observable in some genera ( Milvago and Phalco-
benas (see Plate XV, Fig.2) in the horny sheath, they cannot be detected in the bone of
the bill. (See Plate XII, Fig. 1.) : ih

+ Nitzsch’s Pterylography, translated from the German, edited by Philip Lutley Sclater,
M. A., Ph. D., F. R. a secretary to the Zodlogical Society of London. London: Published
for the Ray Society, by Robert Hardwicke, 192 Piccadilly. 1867. pp. 118, ppl. 10.
6

which, in the main, supports the one founded on the osteological struc-
ture. :

A.—Dorsal portion of the spinal tract deeply divided, and each branch
dilated exteriorly ...... 02.20. 222-20 ce ee eee eee eee Faleones

B.—Dorsal portion of the spinal tract enlarged on all sides, undivided,
and sparsely feathered.

a.—Eyelids with distinct lashes; lumbar tract present ; dorsal por-
tion of the spinal tract sparsely feathered to the caudal pit,
thence diminished and continued as a narrow band along
the caudal vertebre to the oil-gland ........-- Herpetotheres.

b.—Eyelids without distinct lashes ; lumbar tract absent; dorsal por-

tion of the spinal tract in the form of an elongated ellipse,

only contracted into a band immediately in front of the oil-

gland (but even there still broad), consisting exclusively of
scattered. feathers, which become stronger posteriorly.

Micrastures.

The only close relationship between any two groups of this subfamily
isseen in the generalized forms of the Falcones and Polybori (Hieracidea
and Milvago), whose specialized forms (Falco and Polyborus) are so ex-
tremely dissimilar in appearance. In the two genera mentioned, the ap-
proach is so very close as to almost form a transition between the two
groups.* There is a wonderful similarity in the general form and relative
proportions of all the parts, the arrangement of the scutelle of the tarsi
and toes, the character of the plumage, and the size of the species. But
notwithstanding this apparent correspondence of external characters,
they are found to differ in all those osteological characters diagnostic
of their respective groups, and, when their external structure is ex-
amined closely, agree severally with the other members of the groups to
which they belong in an apparently trivial yet really pertinent character,
viz, the cutting of the inner webs of the outer primaries, which is always
essentially different in the two groups. The external diagnostic charac-
ters (associated with osteological, indicated on p. 229) are thus reduced
to the structure of the primaries, as follows:

FALCONES.—Two, or less, outer primaries with their inner webs cut;
this always an abrupt emargination on the first, and situated near its
end. Second or third quill longest ; first longer than the fifth.

PoLy3Bori.—Three, or more, outer primaries with their inner webs cut;
this an oblique sinuation on the first, and near its middle. Third or

fourh quill longest; first shorter than the fifth.

The Falcones comprise very few genera in proportion to the number
of species, which is very considerable; but it is outside the purpose of
this paper to discuss the subject of what the genera of the group are.
Suffice it to say that neither Baza nor Harpagus belong here, as many
have supposed, being members of different groups (Pernes and Ictinie)
of the subfamily Buteoninw. The genus Spiziapteryx, however, which
many consider a synonym of Harpagus, is a true Falcon.

The groups Micrastures and Herpetotheres have but one genus each, so
these are passed by without further notice; but the Polyborine genera
are numerous, and, as they have never been satisfactorily defined, the
following diagnoses are presented :

.* The typical Hieracidee will, upon examination, probably be found to have the super-
ciliary process of the lachrymal much shorter than that of the*typical Falcones, if it does
not approach the extreme brevity of this bone which characterizes the Polyborine group.
a

*

Genera and subgenera of POLYBORI.

A.—Tarsus 3-8 its length longer than the middle toe; outer toe but
little longer than the inner; posterior toe very decidedly shorter
than the inner; claws slightly curved, blunt. Inner webs of
primaries deeply sinuated. Habits chiefly terrestrial.

a. Nostril linear, obliquely vertical, its tubercle concealed.

1, PoLyBorvus. Nostril linear, obliquely vertical, its posterior
end the upper one ;* situated in the upper anterior corner of
the cere. Anterior outline of the cere nearly straight and
vertical. Occipital feathers elongated into a depressed crest.

b. Nostril circular, in the middle of the cere, its tubercle exposed;+ an-
terior outline of the cere doubly curved.

2, PHALCOBAZNUS. Tooth and notch of the tomiaof the bill near-
ly obsolete ; lower jaw nearly naked; outer toe not apprecia-
bly longer than the inner; posterior toe reaching much be-
yond the first joint of the middle toe; claws remarkably blunt,
slightly curved ; posterior face of the tarsus without distinct
rows of quadrate scales; upper tail-coverts remarkably de-
veloped, covering nearly two-thirds the tail; size large.

a. Frontal feathers (of adult) recurved, very soft, lanceolate;
loral and maxillary regions naked; fore-neck feathered.
In the adult, the abdomen, anal region, crissum, upper tail-
coverts, and lining of the wing white; secondaries and tail
tipped with white; other parts deep black. .Phalcobenus.

f. Frontal feathers pointed backward (normally), stiff and
lanceolate; lower jaw and lores densely covered with
strong bristles; fore-neck naked. In the adult,abdomen and
anal-region ochraceous; crissum and upper tail-coverts
black; lining of the wing and tibiz black mixed with ochra-
ceous; breast and nape longitudinally streaked with dingy
whitish ; secondaries not tipped with white. ...... Senex.

3. MILvaco. Tooth and notch of the tomia of the bill distinctly
indicated ; lower jaw normally feathered ; outer toe decidedly
longer than the inner; posterior toe not reaching the first
joint of the middle toe; claws sharp, strongly curved (as in
the Falcones); posterior face of the tarsus with two distinct
rows of quadrate scales. Upper tail-coverts normal, covering
about one-third the tail; size small.

B.—Tarsus scarcely longer than the middle toe; outer toe very much
longer than the inner, which is but little longer than the posterior
one. Inner webs of primaries shallowly sinuated. Habits
strictly arboreal.

4, IpycTER. Nostril circular, near the middle of the cere, its
tubercle either concealed or exposed; anterior outline of the
cere doubly curved. Tarsus without transverse scutelle
either in front or behind.

a. Size large. Bill slender, the tip much produced ; gonys
barely convex, nearly horizontal. Bare superciliary
region very narrow. (See Plate XVIII, Fig. L.)..Ibycter.

6. Size small. Bill thick, the tip only slightly produced ;
gonys strongly convex, decidedly ascending terminally.
Bare superciliary region very wide. (See Plate XVIII,
Fig. 2.) .....- sialeslie wyeswideapaicaitis es avai nina was Daptrius.

7

 

* This is exactly the reverse of the position of the nostril in all other J alconide, in which
its direction is oblique! tAs in the Falcones!
Fic. 1.

pe ON9ranprww

moet
HS

fy
=>

e

PLATE XI.

CORACOID APPARATUS.

(All natyral size.)

Falco anatuu.

. Ibycter americanus.
. Micrastur semitorquatus.
. Herpetotheres cachinnans.

Pandion carolinensis.

. Elanoides forficatus.

. Elanus leucurus.

. Ictinia mississippiensis.
. Rostrhamus sociabilis.
. Buteo borealis.

. Aquila canadensis.

Anterior process of the coracoid.

. Basal process of the scapula.
. Scapular process of the coracoid. ]
 

 

 

 

 
PLATE XII.

SUPRAMAXILLARY AND NASAL BONES.
(Natural size.)

. Fig. 1. Phalcobenus australis.
— 2, Falco anatum.

3. Herpetotheres cachinnans.
4, Micrastur semitorquatus.
5. Pandion carolinensis.
6. Ictinia mississippiensis.
7 Antenor harrisi.
8. Harpagus bidentatus.

{a. Bony tubercle of the nostril.
. Median ridge of the supramaxillary. ]

o
 

 

 

 

 
PLATE XIII.

SUPERCILIARY PROCESS OF THE LACHRYMAL.

(Natural size.)

Fig. 1. Phalcobzenus australis.

2.

on non P Ww

Falco anatum.
Herpetotheres cachinnans.

. Micrastur semitorquatus.
. Antenor harrisi.

. Pandion carolinensis.

. Elanoides forficatus.

. Harpagus bidentatus.

. Superciliary process of the lachrymal.
. Accessory piece. ]
 

 

 

 

 

 

 

 

 

 

 

 

 
PLATE XIV.
(Natural size.)

Fic. 1. Herpetotheres cachinnans.
2. Micrastur semitorquatus.
 

 

 

 

 
PLATE XY.

(Natural size.)

Fre. 1. Hieracidea berigora.
2. Milvago chimango.
 

 

 

 
  
 

AN

ee

 

 
PLATE XVI.

(Natural size.)

Fic. 1. Hieracidea berigora.
2. Milvago chimango. |
 

 

 

 

 
PLATE XVII.

(One-half natural size.)

Fig. 1. Falco aurantius.
2. Hieracidea berigora.
3. Milvago chimango.
4. Phalcobeenus megalopterus.
PLATE XVIII.

(Natural size.)

Fic. 1. Ibycter americanus.
2. Ibycter (Daptrius) ater.
 

   
 

    
 
 

  

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