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TRANSACTIONS

OF

THE ZOOLOGICAL SOCIETY

OF LONDON.

VOLUME XVI.

LONDON:

PRINTED FOR THE SOCIETY :
SOLD AT THEIR HOUSE IN HANOVER-SQUARE;
ANI) BY MESSRS. LONGMANS, GREEN, AND CO., PATERNOSTER-ROW.

1905.

yon oy

PRINTED BY TAYTOR AND FRANCIS,

KED LION COURT, FLERT 8TRERT.

CONTENTS.

I. On the Development of the Skeleton of the Tuatara, Sphenodon punctatus; with
Remarks on the Egg, on the Hatching, and on the Hatched Young. By G. b.
Howes, LL.D., F.RS., and H. H. Swiynerton, B.Sc., Marshall Scholar R. Coll.
Sct. Lond. (From the Huxley Research Laboratory.) (Plates I-VI.) . page 1

I. Contribution towards a Knowledge of the Osteology of the Pigmy Whale (Neo-
baleena marginata). By Frank E. Bepparp, W.A., F.R.S., Prosector and Vice-
Sasa of doe Soap, (aes WINDS), 5 56 5 2 6 0 a eo BF

WII. On the Breeding-habits of some West-African Fishes, with an Account of the
katernal Features in Development of Protopterus annectens, and a Description
of the Larva of Polypterus lapradei. By J. 8. Buverrr, WA. MZ, Trinity
CONG, CHLOTILG A (OQENISS OG DOE) 85 8 be gg a ko LUNG

IV. Third Contribution to the Ichthyology of Lake Tanganyika.—Leport on the
Collection of Fishes made by Mr. J. E. S. Moore in Lakes Tanganyika and
Kivu during his Second Expedition, 1899-1900. By G. A. Boutencger, FL.S.,
EZZOS "(OP 1a bes EXUDE INORG I tas tA ease 0 cop ean hice eae este esta

V. On new or imperfectly-known Ostracoda, chiefly from a Collection in the
Zoological Museum, Copenhagen. By Guorce Srewarpson Brapy, I./.,
IDE ID. DING, SS) CHUB. (CORES LON ).OR%o)) 6 6 ie a 8 o AG

VI. On the Myology of the Tongue of Parrots, with a Classification of the Order.
based upon the Structure of the Tongue. By Guo. P. Muper, A.R.C.S. Lond..
F.ZS., Lecturer on Biology, Londow, School of Medicine for Women; and
Demonstrator of Biology, London Hospital Medical School. (Plates XXVI.-

VII. On Okapia, a new Genus of Giraffide, from Central Africa. By BE. Ray
Lanxesrer, M.A., DL.D., F.RS., .Z.8., Director of the Natural Mstory
Departments of the British Museum, Correspondent of the Institute of France.
(Dies 20:00, O-O,G0I See ggg ic a) ol BNNs 1G oe 6, 6 20S,

iV CONTENTS.

VILL. On the Structure of the Larval Polypterus. By J.S. Bupeerr, M.A., FZ.
(Plates XXXUIT-XROKV.) =. 2 ee ee epaseroiiy

1X. Eedysis, as Morphological Evidence of the Original Tetradactyle Feathering of
the Bird’s Fore-limb, based especially on the Perennial Moult in Gymnorhina
tibicen. By Epwarp Ducen, #.Z.S, (Plates XXXVI-XXXVIIL) . 347

List of the Papers contained in Vol. RVI ad be. ee ee

Index of Species, &e.. . . . rere ee ty Gall

TRANSACTIONS

OF

THE ZOOLOGICAL SOCIETY

OF LONDON.

Vou. XVI.—Parrt 1.

LONDON:

PRINTED FOR THE SOCIETY,
SOLD AT THEIR HOUSE IN HANOVER-SQUARE ;
AND BY MESSRS, LONGMANS, GREEN, AND CO., PATERNOSTHR-ROW.

February 1901.
Price £1 4s. Od.

Taylor and Francis, Printers, | [Red Lion Ovurt, Fleet Street.

TRANSACTIONS OF THE ZOOLOGICAL SOCIETY

VOLUME I.

VOLUME Ii.

VOLUME Iii.

VOLUME IV.

VOLUME SV.

VOLUME VI.

VOLUME VIL.
VOLUME VIII.
VOLUME IX.

VOLUME X. (1877-1879, containing 95 Plates) .

GENERAL

VOLUME XI

VOLUME XII.

OF LONDON.

(1833-1835, containing 59 Plates). . Price
(18385-1841, containing 71 Plates). . ,,
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(1866-1869, containing 92 Plates). . ,,
(1869-1872, containing 73 Plates). . ,,
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. (1880-1885, containing 97 Plates). .,,
(1886-1890, containing 65 Plates). . ,,

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t Only complete copies of these volumes are left in stock.

Continued on page 3 of Wrapper.

TRANSACTIONS

OF

Pek ZOOLOGECAL SOC LET Y
OF LONDON.

I. On the Development of the Skeleton of the Tuatara, Sphenodon punctatus ;
with Remarks on the Egg, on the Hatching, and on the Hatched Yi oung. By
G. B. Howrs, LL.D., F.RS., and H. H. Swinnerton, B.Sc., Marshall Scholar,
R. Coll. Sei. Lond. (From the Hualey Research Laboratory.)

Received May 21, 1900; read May 22, 1900.

[With Plates I-VI. and 18 text-illustrations. ]

ContTENTs. Page

Palm trod Metiont la teteusr stars sare sireasternte Ai seiee scan nln ave aoe ete eT Cote if
PTAA GOLLY rayemeers alavestes cies sue oatehe hava catiee ae te race cn. Aone Oe a 4
owe Met hodspandelveconsthucrlionerree tty iy selenite eee: rif
4. Observations on the Egg, on Hatching, and on the Hatched Young .... 8
Ome LhopActalliS keletoneiaghctars teat nares at tae ae ae can eee aoe 10
General vandvas)towlerminologyaaaemammrer eral tieeiiceair ice: 10
Vertebral Coliminy seinen esc Gere oe oe ton eae 11
Ribsrands sternum cee wo eee eres oe 27

GC Nocoruinall eles” (Cage) co ccaoccecso0od0n0 009000000000 34

they kullvandiavyisceraleAuche sia misesra ere errs warner rr y= 37
@ranio-facialeMiembrane- bones mare anenerr eter cis 51
GarthepAppendicular Skeletontapyqecen neice SORE cen erick icin: 58
LheyPectoral\Girdle:: (252 Gaara ee ater eee eee 58
MhemPelwicr Girdle: 2.5 ics ee ews eee ee ers ree eh evaeh closes 58
Mivewone Bones is cc. 1ie aces sro araqios sy efeasvexmateanietonsbecetcrausiarereie eae: aisles 60

The Carpus and Tarsus, with Phalanges ..............cceeeees 60
Hegel ew) ETUtiGT OM eV Neas) asreyeysico dss 3 wale naire CRSP Rea Sap ooe e os abe Ban Coa Tora 63
8. Summary and Conclusions ..... LOGoo0 oCddUDGaRnD ODOT CODaOUODOOOD 67
9. List of the more important Memoirs dealing with Sphenodon ........ 71
1@,; Wxgdlemethion, OF Wine EWES Ghoccccddoooodecqcoua0000b0ab0aG00000C 75

1. Inrropuction.

ALL work in Reptilian Morphology during the last thirty years has increased the
interest attaching to the creation in 1867 by Dr. Giinther of the Order Rhyncho-
VOL, XvI.—pPart I. No. 1.—J/ebruary, 1901. B

2 PROF, G. B. HOWES AND MR. H. H. SWINNERTON ON THE

cephalia, which now, in its extended form, would appear to embrace a series of
genera and species occupying a truly central position among the terrestrial vertebrates.
Since the publication of Dr. Giinther’s memoir on Sphenodon, the discovery by Baur
and others of its vomerine teeth, and by Spencer of its parietal-eye, have more especially
increased our knowledge of this remarkable animal beyond that which is ordinary.
One of its most distinctive characters is the forward prolongation of the pterygoids
to meet the vomers with apposition in the middle line. ‘The mere forward prolongation
referred to is a feature already recognizable among the Batrachia and Stegocephalia ;
but special interest attaches to the median apposition, as there is little room for
doubt that in that there lies the clue to the reduction and suppression of the para-
sphenoid in the ascending series of the Amniota. This important Rhynchocephalian
character, long recognized in the Crocodilia and Dinosauria, has during recent years
been discovered in the Ichthyosauria! and the Plesiosauria? by Lydekker and others,
and probably in the Pterosauria by Newton®, and it justifies the conclusion that
the living Sphenodon may be the sole surviving representative of an early and
widely ancestral amniote type. While the recent confirmation by Menzbier * and
Pycraft® of Brandt’s discovery in 1839° that the Avian pterygoid may reach the
vyomer, with their further demonstration, that while this is a permanent feature of
some Ratite and the Tinamous among the higher birds, this Rhynchocephalian
character becomes lost during ontogeny under secondary segmentation and co-
ossification of parts, as the progressively modified facial skeleton comes into closer
relationship with the basis cranii, would seem to indicate an origin for the class Aves
from some more primitive reptilian type than might otherwise have been supposed 7—
from something lower than the Dinosauria. Beyond this, Cope in 1870 §, and Seeley
in 18749, have drawn attention to certain Chelonian resemblances in the Rhyncho-
cephalia. In tliis they have been more recently followed by Boulenger, who regards 1°

‘ Lydekker, R.: Brit. Mus. Cat. Fossil Rept. & Amphib., Part 2, 1889, p.5. Of. also Baur, G.: Anat. Anz.
Bd. x. 1895, p. 456 ; and (concerning the Rhynchocephalian affinity) Americ. Nat. vol. xxi. 1887, p. 337.

2 Lydekker, R.: originally in Pl. dolichodirus, ibid. p. 257. Cf. also Andrews, C. W.: on Peloneustes,
Ann. & Mag. Nat. Hist. (6) vol. xvi. 1895, p. 248, and on “The Structure of the Plesiosaurian Skull” in
Journ. Geol. Soc. vol. lii, 1896, p. 246.

® Newton, E. T.: Phil. Trans. vol. 179 B. 1888, p. 5038.

“ Menzbier, M. v.: Bull. Soe. Imp. Nat. Moscou (n.s.), tome i. 1887, p. 492.

> Pyeraft, W. P.: P. Z. 8. 1898, pp. 973-974.

° Brandt, J.: Mém. Acad. Sci. St. Pétersb. (vi.), Sci. Nat. tome iii. p. 81, & espec. pl. xvii. fig. 3 (Rhyncops).

7 Provided the so-called ‘“ hemipterygoid” has the value claimed for it. It must not be forgotten that
Archeopterye appears to have had “ abdominal ribs” (Dames, Palwontol. Abhandlg. Berlin, 1884, Bd. 2,
p. 144), and that “ intercentra” occur in most of the groups of non-Passeres among living birds (Beddard,
P. Z. 8. 1897, p. 465).

* Cope, E. D.: Proc. Americ. Assoc. vol. xix. 1870, p. 233.

* Seeley, H. G.: Journ. Linn. Soce., Zool. yol. xi. 1876. p. 183.

° Boulenger, G. A.: Brit. Mus. Cat. Crocodilia and Chelonia, 1889, p. 1.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 3

“ the affinities of the Rhynchocephalia to the Chelonians as at least as great as to the
Lacertilia; ” while almost the first observation made in the development of the Tuatara
was that by Dendy (98, and 99”. p. 66) of the post-amniotie canal, which, though
probably of wide occurrence, was originally discovered! and is at present known
elsewhere only in the Chelonia, and of the horny “ shell-breaker,” which, being of the
Chelonian type”, places Sphenodon in sharp contrast to the Lacertilia, which, so far

992

as is known, develop a calcified ‘“‘ egg-tooth.” ?

Far reaching as is thus the interest arising from a comparison of the recent Sphenodon
with representative members of the living orders of Reptiles, that with certain extinct
orders and suborders other than those already alluded to is even more suggestive.
The discovery by Credner in the Permian deposits of Saxony of the assemblage of
vertebrate forms he has so aptly termed * the ‘‘ Kotetrapoda,” and more particularly the
genus he has less aptly named Paleohatteria, has materially lessened the structural
gap between the Reptilia and the Stegocephalia; while the description by Lortet, eight
years ago, of Rhynchocephalian remains ® from the Upper Jurassic of the Rhone Basin
which reveal new cranial characters, with that of Crocodilian resemblances in Champ-
sosaurus ®, which, like Acrosaurus’, is believed to have been aquatic in habit, shows
the Rhynchocephalian Order, now all but extinct, to have been in the past extensive
and subject to considerable modification. It is now generally conceded that the
Anomodontia (Theriodontia and Pariasauria) in some respects stand on an even lower
structural level than the Rhynchocephalia ; and, this being so, the recognition among
these of Rhynchocephalian characters—originally by Seeley in Procolophon in 1878 8—
only the more fully justifies the belief in the primitive nature of the Rhynchocephalian

1 Mitsukuri, K.: Journ. Sci. Coll. Tokyo, vol. iv. 91, p. 10. Cf. also Dendy, 99°. pp. 251 & 255.

* Cf. Dendy, A., 99°. pp. 56 & 59, and Parker, W. K., ‘Challenger’ Reports, Zool. vol. i. pl. 3. fig. 1.

° Of. Leydig, F.: ‘Die in Deutschl. lcbend. Arten d. Saurier,’ Tubingen, 1872, p. 110; and Boulenger, G. A.:
on the Ophidian Aipysurus annulatus, in Willey’s ‘ Zoolog. Results,’ Cambridge, 1899, p. 57.

4 Oredner, H.: Allgem.-Verhandl. Naturwiss. Abhandlg. Berlin, Hft. xv. 1891, pp. 1-52.

5 Lortet, L.: Archy. Mus. Hist. Nat. Lyon, Bd. v. 1892, pp. 139. It is interesting to note that Swwranodon
possessed proccelous vertebre.

® Dollo, L.: Bull. Soc. Belge d. Géol., tome v. 1891, p. 151.

7 Andree, A.: Ber. Senckenbg. Naturf. Gesellsch. 1893, p. 21.

8 Seeley, H. G.: Quart. Journ. Geol. Soe. vol. xxxiv. 1878, p. 803. The pterygo-vomerine relationship is
now known to be Rhynchocephalian among Anomodonts in Procolophon and Galesaurus (A. 8S. Woodward,
‘Outlines of Vertebr. Paleont., Camb. 1898, pp. 148 & 152), aud it is probably so in Pariasaurus also (cf.
Seeley, Phil. Trans. vol. 183 B. 1892, p.317). The description of a post-palatine fossa, which in all probability
received a median tonsil (“ bursa pharyngea”) like that observed by Killian (Morph. Jahrb. Bd. xiv. 1888,
pp. 659-690) for living reptiles, as the posterior nares, and of the true posterior nares (p. 317) as ‘‘ anterior
comma-shaped palatal vacuities,” is erroneous. The study of the palatal region of this animal needs re-
investigation.

B2

4 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

Order, and of Sphenodon, its living representative. Since Sphenodon thus occupies
the afore-mentioned primitive position among living reptiles—not to say among the
Sauropsida as a whole—and since our classificatory systems of the Vertebrata, to be of
avail, must be primarily based upon facts concerning parts capable of fossilization, the
special interest attaching to the study of the development of the Sphenodon skeleton
becomes sufficiently evident. And, as involving the Order Rhynchocephalia, the fact
that in one of the most recent, and that which we have found the most rational and
serviceable of classifications thereof!, a distinction has become possible between a
higher and a lower sub-order, in itself raises the interesting question whether in the
development of Sphenodon, a member of the higher sub-order, there may not be passed
through phases characteristic of the lower, to-day unrepresented.

During the thirty years afore-named no available opportunity has been lost by
workers of all nationalities to study the habits and anatomy of Sphenodon, and a list
of the resulting papers is appended to this Memoir (infra, p. 71). Most organs and
systems haye received attention. ‘The most exhaustive contribution is that of the
Japanese Osawa, which is a laborious anatomical treatise extending over 458 pp.
of the Archiv fiir Mikroskopische Anatomie (cf. list, Osawa, 96-98); and, while
grateful to him for this, it is with much astonishment that we have to record his
final conclusion (98 ». p. 852, and 98°) that Sphenodon is an Agamid—a reyersion to
the view of Gray (1831), adopted and afterwards forsaken by Cope *, revived by
Peters (70), and rejected by Giinther (69. p. 624) °.

2. MATERIAL.

In 1894, when Professor Dendy was appointed to the Chair of Biology in the
Canterbury College of the New Zealand University, one of us, in regular correspondence
with him, sought to impress upon him the desirability of doing all in his power to
secure without delay material for the study of the development of Sphenodon, not
knowing at the time that our mutual friend, Prof. Baldwin Spencer, 1daltishs; Or
Melbourne, had also approached him on the subject. With what enthusiasm and at
what personal cost he responded to the desire, his published memoirs (Dendy, 98,
99°, 99>) amply testify. On hearing of his success in the field, no time was lost

1 Boulenger, G. A.: Ann. & Mag. Nat. Hist. (6) vol. xi, 1893, p. 204.

2 Cope, E. D.: cf. Proc. Acad. N.S. Philad. 1864, p, 227, and Proc. Americ. Assoc. vol. xix. 1870,
p. 233.

° Tt has always been to me inexplicable why Huxley should have refused to admit the validity of the Order
Rhynchocephalia. Well do I remember how, in conversation, he once remarked to me that “ Sphenodon is a
lizard and only a lizard!” but, this notwithstanding, his final printed statement and proposal to create, for the
reception of Hyperodapedon, Rhynchosaurus, and Sphenodon, the group of the “Sphenodontina” (Quart.

Journ. Geol. Soc. vol. xii. 1891, p. 691) would seem indicative of a compromise suggestive of an approaching
conviction.—G. B. H.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 9)

in drawing his attention to certain of the more interesting problems (duly set forth
in the pages of this Memoir) presented more especially by the skeleton and teeth
of the adult animal. In reply, he expressed the hope that one of us would undertake
this portion of the work, and offered, with a generosity and friendly appreciation for
which we tender him our heartiest thanks, to give ali the necessary material he could
command if we would acquiesce. ‘There accordingly reached us in the autumn of
1898 a large series of specimens, treated, for the younger stages with corrosive
sublimate and alcohol, for the older with alcohol alone. From these, after preliminary
examination, the undermentioned were selected, as embracing the period of skeleto-
genesis ; and, concerning those which remain, Prof. Dendy has very generously
acquiesced to the proposal that Dr. Elliot Smith and Mr. E. J. Bles, of Cambridge,
should work out respectively the development of the brain and urinogenital organs.

List of Young Specimens Investigated (15 in all).

Stage. No. Date of removal from Egg.
1 OX a a ek et a 87. Jan. 25, 1898.
1s Sade Saou BASIS 39 a. Unknown.
(ah Cane eee eee ran 52a. Jan. 30, 1899.
der Rattiecoeniaatiaann la. End of Jan. 1897.
URE ier eps cre hier 142. March 8, 1898.
Ry. abe eee re 154. April 5, 1898.
18) ie oa et are eRe 159. May 12, 1898.
yy | Janno serooecemenaae 162. June 24, 1898.
JRSP. vasueMaueu menses
Sie Renter m amen II
SII. estoccumemeddancen IV.
Serene are aerdiracat la. Hatched Dec. 8-9, 1898.
Sie a eeoneee cadet 194. >» Dec. 27, 1898.
Sie secon nieces 138. No details.
ADM geatuonnee mene tiee Il

The following are the details concerning the individuals incubated and afterwards
reared in our own Laboratory.

Stage. Length in ems. Remarks.
JS ngdaoadaseoe 6:3 Died in egg, 13.11.98.

f Hatched prematurely with
SLR oe a1 i) excessive yolk, 22.11.98.
FTN el 15 Hatched 14.1, died 1.5.99.
SI Voit saceaseenaeenn bes 1 Shea pale ec na

14.1.99.

NER on ae aetciiaic 15 Hatched 19.1, died 18.5.99.

(ET aiSappanenenaed Ne » 24.1, died 18.5.99.

6 PROF. G. B. HOWES AND MR, H. H. SWINNERTON ON THE

In the foregoing list the stages and numbers are those of Dendy’s series, described
in the Quart. Journ. Microsc. Sci. vol. xlii. p. 10. Those marked * were found requisite
as our investigation advanced, and were very kindly supplied by him at our request,
and those marked + were incubated in our own Laboratory from unhatched eggs. The
latter, six in number, packed close in moist sand in a 1-lb. canister with a perforated lid,
were brought over by Mrs. Dendy and kept during the voyage from New Zealand in her
cabin. One only decomposed, and of the five which remained, three ran the full deve-
lopmental period, the enclosed young making good their own escape. These lived from
three to four months, and for their reception we have added to Dendy’s series a Stage T.
At this stage the coloration is the same as at S, but as an advance upon that there is
a complete absence of all traces of the yolk-sac and shell-breaker, and the appearance
in the thoraco-lumbar region of the all characteristic median dorsal languets (spines,
auct.), such as are already present at Stage S in the so-called “nuchal” and the caudal
tracts. These appendages, whose existence is expressed in the native name Tuatara ',
are liable to no slight individual variation. ‘Three tracts are present in the adult, viz.
“nuchal,” thoraco-lumbar (“dorsal”), and caudal, as recognized by Boulenger in his,
the latest, diagnosis (89. p. 2), with consequent scapular and sacral intervals. Buller
(76. p. 324) and Newman (77. p. 230) have called attention to the existence in the
region of the cervical space of a conspicuous pigment-patch; and, concerning the
numerical variation of the “spines” in the adult, they give for the “nuchal” series
10-14, for the thoraco-lumbar 15-20. From examination of eleven specimens present
in our own collection and that of the British Museum of Natural History, we find the
extremes range from 6 to 14 for the “nuchal” and 15 to 24 for the thoraco-lumbar
series. In two specimens of our Stage T they number 10 and 18 respectively.

With a view to ascertaining the limits of individual variation, and thereby
rendering the present memoir as complete as possible anatomically, we have examined
all the dried skeletons within our reach—viz., the complete skeletons of nine adults,
fragments of some six to eight others, and the complete skeleton of a half-grown
individual in the possession of the Royal College of Science, Dublin. For the
privilege of examining all but two, which are at South Kensington, we are
indebted to Prof. A. C. Haddon, F.R.S., to Prof. C. Stewart, F.R.S., of the Royal
College of Surgeons Museum, to Dr. R. F. Scharff, Keeper of the Natural History
Department of the Science and Art Museum at Dublin, and to our friends in the
British Museum of Natural History.

Beyond this, we have had recourse where necessary to dissection of six spirit-
specimens in the Teaching Collection of the Royal College of Science, two of which
were presented by Prof. Dendy in the spring of 1899.

* Cf. Newman (Taylor cit.), 77, p. 222.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 7

3. Mertnuops AnD RECONSTRUCTION.

Methods.—Dissection was resorted to only in the later stages, and wherever the
elements under consideration were fully formed. Throughout the earlier stages, and
in the later where necessary, microscopic sections were relied upon; and further, as
for example at Stage S and in dealing with the carpus and tarsus, dissection was duly
checked by section, as a means of ensuring accuracy of detail.

The microscopic sections were in all cases mounted serially, the plane of section
being determined by the object in view (as set forth in the accompanying description
of the Plates). After preliminary experiment with the Green Lizard (Lacerta viridis),
it was found that differentiation of the skeletogenous tissues could best be obtained
by staining in bulk with Ehrlich’s hematoxylin, and afterwards on the slide with
Griibler’s orange G. For this suggestion and much subsequent aid we are indebted
to Mr. M. F. Woodward, Demonstrator of Zoology, Royal College of Science, London,
than whom no better manipulator or master of micro-chemical technique exists ; and
we found, as our work proceeded, that much time is to be saved by dissolving the
orange in 70 p.c. alcohol, with the addition of a few drops of glacial acetic acid,
thus eliminating the tedium arising out of the use of a mere aqueous solution. ‘The
results of this method are exceedingly satisfactory, cartilage being as a rule differen-
tiated blue, bone in all its forms deep yellow, while the other tissues behave each in
its own way.

Reconstruction—Since the time has now arrived at which mere dissection is
insufficient for the study of the facts of skeletogenesis, recourse was had to the
so-called Bornean method of reconstruction from microscopic sections!. We were
under the necessity of working with thin plates, and found that if made of the
Bornean mixture of beeswax and turpentine there was difficulty in preparation and
liability to snap. By substituting vaseline for turpentine, we entirely overcame all
this, and we can confidently recommend our mixture as reliable.

The figures which constitute Pl. III. and figs. 7 and 10 of Pl. VI. are all from
models prepared from plates thus made. For the most part the sections of the animal
were cut to a uniform thickness of 10 », and each plate made to that of 1 millim.
Tracings were then drawn upon the plates, by means of the camera lucida, of sections
at regular intervals, determined by the degree of magnification (every fourth section
for a magnification of 25, every third for that of 33, and so on). In cutting out the
tracings, trabecule were left where necessary for holding the parts together during
reconstruction, and afterwards cut away. For the process of cutting, the best results
were obtained by the use of a needle, the plates being laid upon glass

1 Barlier achievement in the same direction must not be overlooked. In England it stands memorably
associated with the Huxleyean traditions: ef. E. T. Newton, “On a New Method of Preparing a Dissected Model
of an Insect’s Brain from Microscopic Sections,’ Journ. Quekett Microscop. Club (I.), vol. v. 1878, p. 150, and

Qu. Journ. Micr. Sci. (n. s.) vol. xix. p. 340.

8 PROF. G. B. HOWHLS AND MR. H. H. SWINNERTON ON THE

‘The tracings, as cut out, were laid flat in superposition, adhesion being effected by
carefully running a heated wire along their edges. ‘The use of colour was deemed
desirable, but a possibility of error seemed likely to arise were the models coloured
after completion. This, however, was obviated by colouring the tracings before they
were cut out; and a perfectly reliable result was obtained by the use of ordinary
oil-paint dissolved in xylol, to secure rapidity in drying. In plates thus treated, the
melting together of their edges ensured the diffusion of the colour necessary to
produce the final realistic result.

4. OBSERVATIONS ON THE Eaa, on HATCHING, AND ON THE HatcHEep Youne.

During the period of Prof. Dendy’s activity, both as collector and investigator, which
led to the publication of his two pioneer memoirs on the Development of Sphenodon
(Dendy, 98°, 98°), there arrived in New Zealand two German naturalists—one Dr. H.
Schauinsland, of the Bremen Museum, the other Prof. G. Thilenius, of Strasburg; one,
if not both, of them sent out under the auspices of the Berlin Academy. Each has
since published preliminary reports upon his investigations (¢f. List, p. 74), without,
however, in any way alluding to Dendy’s work ; and this is the more regrettable, since
in matters of small detail their statements both differ from and supplement his—while
it is the more unaccountable, since one of them was permitted by the New Zealand
Government to explore the same island as Dendy, with the aid of the very collector he
had employed. Since neither of them has written upon the skeleton, we omit further
reference to their work, except so far as it concerns the newly-hatched young. Dendy,
in defining his Stage 8, inclined (99°. p. 59) to the belief that the yolk is still pendant
at hatching, and was unable to decide definitely upon his surmise (pp. 79-80) that the
olfactory cellular-plugs which he discovered are at that period “removed.” Schauins-
land, on the contrary, both figures the yolk and describes the nasal plug as absorbed
shortly before hatching (98°. p. 312), and there can be no doubt he is correct. It is
but just, however, to Prof. Dendy to state that in a letter to one of us, antedating the
publication of Schauinsland’s notes, he had corrected his former statements (cf. letter
to ‘ Nature,’ vol. lix. p. 340), having discovered that the embryos which had led him to
believe that both yolk and plug might be present on leaving the egg had been
prematurely hatched.

Concerning the newly-hatched young, he further points out that the pineal eye is
‘plainly indicated by an irregular scale, surrounded by eight or nine others, radially
arranged, and all much larger than the surrounding granules,” an observation which
we can confirm. And to this we would add that the supra-pineal area of the skin of
the head is at hatching transparent and pigmentless, and that it remained in that
condition throughout the four months our young ones were alive.

3efore passing to the main subject of this Memoir, we desire to record some
observations pertinent to those communicated by us, in conjunction with Dr. Dendy,

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 9

in the above-mentioned letter to ‘Nature.’ Firstly as to the rupture of the egg-shell,
to the symmetrical ‘‘clean cleft” character of which we drew attention. The
following is a drawing of the shell of one of the eggs therein referred to which ran
the full time; and in correspondence with Prof. Dendy concerning it and our
suggestion that it seemed to indicate that the shell-breaker may be an actual cutting-
instrument, he has authorized us to state his own view, since formed, on opening an
egg at Stage S, nearly ready to hatch. He observed that the moment a small
puncture is made in the shell, that “splits of itself, very suddenly and with almost
explosive violence, reminding one of the bursting of a seed-vessel ;” and he remarks
that it has been suggested to him that the splitting may have been assisted by

Fig. 1.

Ruptured egg-shell of Sphenodon after the escape of the enclosed young.
Full time. Nat. size.

absorption of moisture from without, by the allantoic fluid!. He reverts to the analogy
of the well-known “ Prince Rupert’s drops,’ and concludes that “the function of the
very sharp shell-breaker is probably to make the small incision ;” and that when that
is done, the egg, being in a condition of high tension, simply bursts open. And he is
the more inclined to this view from having noted that the shell of an egg contained
in sand which had been “ somewhat excessively moistened”? prematurely burst, and
revealed within its interior a dead embryo in an insufficiently advanced stage of
development.

In the afore-mentioned letter to ‘Nature’ we recorded certain details concerning
the treatment up to the time of hatching of the eggs brought us by Mrs. Dendy. ‘The
three young Sphenodons which from these we successfully hatched out were kept in
confinement in the incubator (Hearson’s, size A I.), at the temperature at which they
were hatched—viz. 25° Centigr. They were fed upon mealworms, small earthworms,
cockroaches, and flies, as best obtainable. For these the individual taste was
observed to vary somewhat. One little creature exhibited a decided preference for
mealworms, and a “ tug-of-war” for the possession of an earthworm or cockroach was
a not unfrequent occurrence.

Cf. also Dendy, 99°. p. 251.
VOL. XVI.—PaRT I. No. 2.—February, 1901. c

10 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

The bottom of the vivarium was covered with coarse sand to a depth of about one
inch, and in one corner a water-bath was sunk; while a piece of corky-bark was
introduced, which presented to the little captives a vaulted retreat. While to the
latter they would readily retire, they exhibited a decided preference for the darker
recesses of the chamber. ‘Their movements during the day-time were very active, the
passing of a finger-tip, the point of a pencil, or a piece of india-rubber tubing over the
elass front of their dwelling, being sufficient to entice them forward, ‘The tendency to
burrow evinced itself during the second month—the actual date of the first effort being
March 9th in one case observed. ‘They exhibited a fondness for reclining in the water,
in which they would lie at full length, the top of the head being usually kept above
the surface. It was noticed that when, on leaving the water, the whole body was wet,
an area surrounding the pineal eye always remained dry ; and, concerning the use of the
“bath,” it was observed that if an earthworm seized by the Lizard happened to be
beset by sandy particles, recourse was had to the water and a “ washing” of it before
it was devoured. The prey was never swallowed as soon as seized, but always at first
held between the jaws and more or less masticated.

The first ecdysis in the case of the largest specimen (T‘" p.5) was observed to take
place about March 9th,—7. e. about 7 weeks after hatching.

Under the conditions above-described our little Sphenodons thrived and grew fat ;
7. é. they increased in length during the four months we kept them alive from 8 cm.
to 15-17 cm. ‘The near occurrence and manner of their decease, however (all three
having died in the “bath” within a period of 17 days), points to a common cause of
death. We suspect that this may have arisen from our having unconsciously con-
tinued to liberally feed them into the period normal to hibernation (April to middle of
August!); but, on the other hand, it may have been the mere result of over-feeding
on our part (if indeed that may not have been in turn aided by the attentions of night-
watchers and others who were ‘“ interested”). Whichever be the case, the salient
feature of the dead animals was a superabundance of fat; and we found post mortem
that this was evident externally in life, had we but known it, in the great enlargement
and tenseness—due to its accumulation—of the dorsal languets and certain wregular
folds of the skin originally described by Gray”; 7. e. that undue distension of these
may be an index of over-feeding—an observation to be borne in mind by those who
may yet be so fortunate as to rear this species in captivity.

5. ‘THe AXIAL SKELETON.
General and as to Terminology.—The adult skeleton of Sphenodon has been so fully
described in its modern aspects by Siebenrock (93) and Osawa (98 °) that recapitulation
of its general features is here unnecessary. Before, however, we proceed to details

’ Cf, Schauinsland, 98, p. 702 (for Stephen’s Island).
* Cf. Gray, 42. p. 72.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 11

and the study of its development, we desire to deal briefly with certain facts
and matters of terminology which are necessary to render clear our method of
procedure. Admitting for the vertebral column of all terrestrial vertebrata a primary
classification of the parts in relation to the sacrum, the time-honoured classification
of the pre-sacral portion of that of the Amniota into cervical, so-called “dorsal” or
thoracic, and lumbar regions, is now wholly insufficient for purposes of accurate
description and comparison. ‘The term *‘dorsal,” being one of orientation, is mis-
applied. ‘ Thoracic,” although applicable to the middle region in the mammal—as
embodying the region enclosed by elongated rotatable ribs and bounded posteriorly by
the diaphragm—cannot with precision be applied to that of the lower Amniota, inasmuch
as it presupposes the existence of a post-cardiac septum (diaphragm). The so-called
“ diaphragm ” of birds (Huxley’s ‘‘ oblique septum ”) is pra-cardiac, and the subdivision
of their celom into pulmonary and cardio-abdominal compartments is in marked
contrast to that of mammals, which is pulmo-cardiac (or thoracic) and post-cardiac (or
abdominal). Further, when it is remembered that within the reptilian series various
modes of coelomic subdivision occur, and that tree ribs in both birds and reptiles may
extend beyond the limits of the pulmo-cardiac region, the application of the term
“thoracic” to the whole of that portion of the body which bears them is apt to lead to
confusion. And when, in addition, there are considered the presence of free ribs in
the lumbar region of at least the young of some mammals’, the great variation of the
ribs both in the lumbar and cervical regions of the Amniota generally, and especially
that of the sternum in all its relationships, simplicity and greater uniformity in our
ideas are to be ensured by enumerating the several segments of their pree-sacral
vertebral skeleton by reference to the sternum—and we accordingly propose to substitute
the terms presternal, sternal, and poststernal, for the more familiar but arbitrary
“ cervical,” ‘ thoracic,” and “ lumbar,” delimitating the regions by reference to the one
organ which renders a series of terms necessary ?.

Vertebral Column.—Concerning the adult vertebral column as a whole, we have not
met with any numerical variation of its parts beyond that involving the relationships
of the sternum duly considered in the sequel. For the caudal region the maximum
number of vertebre observed by us was 34 (two less than that originally recorded by
Giinther [67. p. 605]), and for the precaudal we found it always 27, viz., presternal 8,
sternal 3-4, poststernal 15-14, sacral 2, with one exception for the preesternal series.
To an exceptional condition of the sacrum in another individual we shall return.

During the past fifteen to sixteen years the study of the detailed constitution and early
development of the vertebral column has received an altogether exceptional amount of

! Fa. Homo, juv.: Rosenberg, Morph. Jahrb. Bd.i. p. 111.

2 On the other hand, it has been pointed out by one of us (‘ Nature,’ vol. lvii. p. 577) that in the Batrachia,
in the absence of a costal sternum, delimitation becomes possible only in relation to the sacrum, whereupon
the prasacral vertebra are best dealt with collectively. The same principle applies to those Amniota in which
the sternum has been lost; while in the absence of a sacrum, as in the Ophidia, the course is obvious.

oO
ca

12 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

attention, mainly as the result of paleontological discovery by Cope!, Gaudry *, and
Fritsch ®; leading to the recognition of the so-called rhachitomous, embolomerous, and
other similar conditions, which have received at the hands of subsequent investigators
correspondingly appropriate names. Both on the embryological and the paleonto-
logical sides, a considerable amount of evidence has been brought forward for the
belief that some such complex type of vertebra as these, @. ¢. one in which each vertebral
segment was made up of a series of paired elements, was the ancestral one, and that
the various types of vertebral structures characteristic of the living groups may have
resulted from diverse modification (inequality of growth and suppression) of these.
And, in the attempt to substantiate this belief, Manner, in the latest paper* on the
subject, has sought to show that from the first period of its differentiation in cellular
tissue, the individual “ sclerotome ” of the Lacertilian is a compound structure. Goette,
basing his arguments, like Manner, mainly upon the study of the Reptilian backbone,
has concluded ® that the vertebre of the living “ digitata” have arisen from the embo-
lomerous type, and he regards the rhachitomous type as “neither primitive nor
independent, but transitional.” If, however, the relationships of these are really direct,
we would rather transpose the order, since we regard the greater extension of the
skeletogenous tissues, and consequent deeper constriction of the notochord, occurring in
the embolomerous type as indicative of advance upon the rhachitomous, as already
pointed out by Gadow®. He, working on this basis, has simplified our conceptions ot
the fundamental constitution of the diverse forms of vertebral structure represented
among the living vertebrata, beyond his predecessors, by the introduction of a
systematic terminology based on the supposition that all surviving forms of vertebre
are constituted more or less of two pairs of dorsal and two of ventral elements
symmetrically disposed, and that7 “ the solution of the composition of the vertebral
column is given by the metameric repetition ” of these, “the origin of which can be
traced in fishes.” His terms “ basi-” and ‘‘ inter-” ‘‘dorsalia,” “‘ basi-” and “‘inter- ”
“ ventralia,? are most welcome ; and the arguments and conclusions drawn by him
certainly furnish a possible explanation of some of the great anomalies arising out of
the mere study of the adult vertebral column among living forms—as, for example, the
intervertebral disposition and independence of the “chevron bones” of the Amniota,
and the vertebral disposition and confluence with the vertebral bodies of the “ hemal
arches” of the Urodela.

1 Gope, E. D.: Americ. Nat. 1878, p. 327; Proc. Americ. Philos. Soc. vol. xvii. 1878, pp. 510-526 ; Trans.
Americ. Philos. Soc. vol. xvi. 1886, p. 243.

* Gaudry, A.: Enchainements d. Monde anim. Foss. Prim., tom. i. (Paris, 1883), p. 263.

’ Fritsch, A.: Fauna d. Gaskohle d. Permform. Bohmens, Bd. ii. 1889, pp. 14 & 24. Cf. also Baur, G.:
Biol. Centralbl. Bd. vi. 1886, pp. 382 & 353.

‘ Minner, H.: Zeitschr. wiss. Zool. Bd. Ixvi. 1899, p. 43.

> Goette, A.: Zeitschr. wiss. Zool. Bd. Ixii. 1897, p. 390.

® Gadow, H.: Phil. Trans. vol. 187 B. 1896, p. 1.

7 Op. cit. p. 50.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 18

Certain it is that this subject, as it now stands, forms one of the most fascinating
chapters in the vertebrate morphology of our time. Our own researches begin at the
period of differentiation of actual skeletogenous tissue, and while, concerning the
supposed original complexity and general uniformity in origin of the parts of the
vertebral body, we retain an open mind, we question if, in matters of detail to be
referred to in the sequel, theories, in their growth, have not been at times unconsciously
read into the supposed record of facts.

First differentiation of the Skeletogenous Tissue——The earliest stage which we have
investigated is Dendy’s P, and a median longitudinal section through any portion of the
skeletal axis at this stage reveals the presence of a central notochord, ensheathed in a
thin structureless and deeply staining cuticle or chordal sheath (elastica externa of Gadow
[nc.s., Pl. I. fig. 2]). This is seen to be in turn invested by a continuous skeletogenous
sheath, composed of a thickly disposed mass of small cells, containing relatively large
nuclei. There are some 9-10 rows of these, and their close compression gives to the
tissue, when examined under a low magnifying power, the appearance of being feebly
longitudinally striate. ‘The notochord itself consists at this stage of comparatively
small vacuolated cells, arranged in an irregular manner, and differentiated peripherally
into the usual chordal epithelium (nc.e.). Central or other differentiation there is
none.

Comparing with the foregoing a lateral longitudinal section, the superficial cell-
rows of the skeletogenous layer are seen to be more closely approximated than the rest,
and in addition there are (fig. 1) differentiated within the area of this more closely
aggregated stratum a series of metamerically recurrent masses (¢.p.) of cells, generally
more rounded than the rest. They are the developing intercentra ; wherefore it follows
that in order of differentiation these are the first formed skeletal elements.

When the corresponding parts are viewed in transverse section, the skeletogenous
layer is seen to completely encircle the notochord, constituting a skeletogenous sheath,
the aggregation afore-named being apparent (7.p.) as a couple of symmetrical tracts
which are ventro-lateral, widely separated in the trunk-region (cf. fig. 2), closely
approximated in the ventral line in the caudal (fig. 5). The neural arches are at this
stage first differentiated, in the form of bilaterally symmetrical upgrowths of the
skeletogenous sheath (fig. 5, m.a.), separated by a wide interval in the mid-dorsal line.

Stage &—A transverse section through an intervertebral region at this stage shows
that, concerning the skeletogenous sheath (¢.a., text-fig. 2 and Pl. I. fig. 6), the cells
remain practically unchanged, their nuclei when examined under a high power presenting
the oval contour indicative of mutual apposition, so characteristic of the earlier stage
afore-described.

Comparison of a similar section through a vertebral region shows (text-fig. 3) that
chondrification has there set in, but not at all points—for, while laterally hyaline
cartilage is now present, in the form of paired masses (c.v.), continuous with the
now cartilaginous neural arches (v.a.) and confined to the superficial layers of the

14 PROF. G@. B. HOWES AND MR. H. H. SWINNERTON ON THE

skeletogenous sheath, in both dorsal and ventral middle lines the latter (s.s.) has
remained unchanged,

Comparison with the foregoing of a lateral longitudinal section at a slightly later
stage, shows (Pl. I. figs. 7 & 8,¢.v.) that these lateral chondrites encroach upon the
skeletogenous sheath from without inwards, rapidly involving its deeper layers, until its
innermost limit is reached. ‘hey also effect the replacement of the afore-mentioned
median portions, but by union within the deeper layers and subsequent extension in
the opposite direction—/. e. from within outwards, as is seen at c.v. in Pl. L. fig. 6,
which is that of a median longitudinal section at this period.

‘Lhe above described processes continue until chondrification of the vertebral portions of
the skeletogenous sheath is compiete, and there thus results a metameric segmentation

Transverse sections through the poststernal region of the trunk of Sphenodon. 2. Intervertebral; 3. Vertebral,
drawn for comparison. Camera lucida x 70.
c.v. Cartilaginous vertebra; 7.p., primitive paired intercentrum; my., myelon; n.a., neural arch; nc.e.,
notochordal epithelium: ne.s., chordal sheath; 7.¢., trunk rib; s.s. skeletogenous sheath; ¢.a., inter-
articular tissue (intervertebral portion of skeletogenous sheath).

of the vertebral axis, whereby a series of segments become recognizable, each comprising
a centrum, an intercentrum, and a pair of neural arches; and the facts justify our
regarding the centrum as of paired origin—a view which lends support to Gadow’s
conclusion that it represents the fused “interventralia” of the lower vertebrate forms.
As is well-known, the chevrons and presternal or cervical intercentra present in
most Lacertilia may, by shifting, come into secondary relationship either with the
vertebre in front of them! (by which they may even be carried down on autogenous
hypapophyses, as in the neck of the Mosasaur Tylosaurus?), or with those behind
‘ Be, Anguide, Varanidee, Helodermatide ; and, with co-ossification, Mosasaurus, some Varanide, and

Pseudopus. (Cf. Boulenger, P. Z. 8. 1891, p. 113, and Gadow, Phil. Trans. vol. 187 B. 1896, p. 30).

* Cf. Osborn, H. F.: Mem, Americ, Mus, Nat. Hist. vol. i. 1899, p. 171; and also Americ. Nat. vol, xxxiy.
1900, p. 1.

ie

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 15

them, asin Tupinambis?. This notwithstanding. since the anterior element of the whole
series (that lying between the skull and first vertebra) is the first intercentrum, pre-
cision and uniformity are gained by enumerating it in correlation with the centrum
behind it, and so on for the whole series which follow—as has been done, for example
by Gadow, for the chevrons, though not with that uniformity which is desirable. The
method mostly adopted, especially in illustrations, of associating with the numeral
indicative of a given chevron that denoting the vertebra in front of it, as has been done
with descriptions of the skeleton of the adult Sphenodon from Giinther to Osawa, leads
to confusion and must be given up.

Passing now to the intercentra, a marked advance is seen to have taken place in
those of the anterior twelve body-segments and the tail. At Stage P the intercentral
bodies are everywhere paired. At Q, fusion in the mid-ventral line has come about in the
anterior region (cf. Pl. I. fig. 8, 7.p'.). In the case of the first four bodies, the contour
of the fused product gives no indication of its paired origin, but from the fifth to about
the twelfth (as determined by very careful examination of serial longitudinal sections)
a median depression remains. ‘These facts are embodied in column Q of our table on
p- 27, and perusal of them would seem to indicate that fusion of the paired intercentra
takes place antero-posteriorly.

At Stage P, owing to the absence of demarcation between tle cranial and vertebral
portions of the differentiating tissues, the enumeration of the centra had to be
determined by reference to the sacral region, 7. ¢. the segments had to be worked out
in postero-anterior succession. ‘The numerous practical difficulties arising from this
necessity, leave us in doubt whether the first and second intercentra are or are not
represented at this stage. Hence the ? in our table, column P (p. 27). This con-
sideration would seem to throw some doubt upon the paired origin of these first
two intercentra; but, judging from the fact that from segments 12 to 5 the unpaired
intercentra at Stage Q still show traces of paired origin, and that in segments 4 and 3
these elements are proved to be beyond doubt originally paired, we deem it fair to
conclude that the same conditions apply to segments 2 and 1.

It may be remarked that at this stage (Q) the union of the first centrum with
adjacent parts is effected. While it fuses (fig. 8a) completely with the second inter-
centrum (7.p’.), it does so only peripherally with the second centrum, and that so as to
enclose at * a central mass of undifferentiated tissue.

The neural arches have at this stage completely united in the dorsal middle line and
are fully chondrified.

Passing to the caudal region, the intercentra of its fourth and succeeding vertebral
segments, by an astonishing rapidity of growth, have acquired a characteristic elongation,
each extending downwardly into (Pl. I. fig. 7, 7. p.") the substance of the tail, but
without meeting its fellow. Although they are chondrified, and at this stage differ-
entiated in advance of their homologues—the paired intercentra—in front, their cells

. Cf. Boulenger, G. A.: op. cit. p. 114.

16 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

are still more closely aggregated than those of the centra, wherefore they appear under
the microscope dark and highly conspicuous.

Stage R.—This stage is most noteworthy for the completion of chondrification in
the median plane (cf. Pl. II. fig. 11) of the vertebral bodies, throughout the whole
length of the column, and for the lateral extension of these. Ossification of them has
now set in, chiefly in the dorsal and ventral surfaces as seen in transverse section
(Pl. II. fig. 11, 0.v.). The neural arches begin to ossify independently of each other
and the centrum, by an identical and similarly superficial process, as represented (for
Stage S) at Pl. IT. figs. 4-6.

At this stage a remarkable change, for which we were not prepared, is undergone
by the intercentra of the segments numbering 11 to 29 (7. e. those between and
including the third sternal and second caudal segments), viz., the complete disappearance
of those belonging to segments 13 to 25 (ef. table, column R, p. 27); and the tendency
to disappearance, to an extent which renders it difficult to identify their presence,
for segments 11 and 12 and 26 to 29. We are unable to say at this stage by what
process this removal is effected, whether by absorption into the intervertebral tissues
or otherwise; but, in view of the discovery of this remarkable fact, it is the more
astonishing to note that while one pair (viz. those of the third caudal segment)
remain in their primitive condition, those which follow this in order of succession
behind, while still unossified, have coalesced distally, enclosing the caudal canal, to
form the so-called “ chevrons,’—which are thus proved to be the direct derivatives of
primary paired intercentra.

Stage S.—Viewed in median longitudinal section, the salient advances at this period
are seen to be four in number. Firstly, the ossific tracts, described in the previous
stage (Pl. I. fig. 10, 0.v.), when viewed in transverse section (Pl. II. figs. 4 & 5), are
seen to be extending into the lateral cartilaginous expansions, which are being rapidly
absorbed over the areas marked f. Internally to these ossific centres and immediately
surrounding the notochord, there are marked signs of calcification revealed by the
selective action of our reagent. Exactly the same processes take place in the ossifica-
tion of the centrum of the atlas (os odontoideum) as of an ordinary vertebra (cf. Pl. I.
fig. 9a’).

The advance in ossification of the vertebral bodies (0.v., Pl. I. fig. 10) is seen to go
on hand in hand with the assumption of a more truly hyaline character by those
portions which are still cartilaginous. These (as viewed in longitudinal section) are
seen at the same time to undergo a marked change in shape, becoming thinned
over the centre of bony deposition and thickened at and towards their extremities—
7. é., an inverse development of bone and cartilage is recognizable, in proportion as the
centre of each developing vertebra is approached.

In the intervertebral regions (¢.a., Pl. I. fig. 10) the cells of the skeletogenous sheath,
still closely crowded, retain, in the elongation of their nuclei, a character originally

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 17

common to the whole sheath; but there has appeared around them a feebly hyaline
matrix. ‘Ihe now clearly recognizable differences in the parts generally admit of the
application of the term interarticular tissue to these intervertebral areas ; and we desire
to emphasize the fact that though they are feebly hyaline, “ intervertebral disks ” are not
present—the hyaline matrix, dense and resistant for the vertebral bodies, diminishes
markedly as the extremities of the centra are reached, and at these fades into the more
flexible interarticular tissue, there being no hard and sharp line between the two.

The process of differentiation at this stage is most noteworthy for the full formation
of an important constituent of the individual vertebra, which it so happens our
reagents differentiate with startling effect. This, which we propose to term the chordal
plate, is located transversely in the central and most constricted part of the developing
vertebra. We have encountered it (Pl. I. fig. 10, ».p.) in all regions of the column,
from the first (odontoid) vertebra (fig. 9) to well into the region of the tail. Micro-
chemically, it reacts in a totally different manner to the reagents we have employed to
anything else thus far described, wherefore there is no room for ambiguity concerning
it. Its general matrix, which is extensive, stains a deeper blue than any other form of
skeletogenous tissue which is present, and when examined under a high power its very
conspicuous appearance is found to be due to the extent of its matrix and the presence
of regular circular spaces, each filled by a cell which hardly stains at all and contains
a conspicuous rounded nucleus. From its general appearance and disposition we
have no doubt that it represents the so-called chordal cartilage described by Gegenbaur
in 18621 in the Urodela and Reptilia, and since observed by Field, Fraser, and Stohr
in certain allied forms and by Goette in the Anura.

Gadow has given (op. cit.) an admirable summary of the work of these investigators,
all of whom regard this as chordal in origin, and of others who seek to disprove that.
With the latter he is himself agreed. He deals with the question in full in Lacerta
and the Geckos among Lacertilia, and since we are dealing with Sphenodon, it is with
his statements that we are alone concerned in detail. Having referred (op. cit. p. 11)
to an “occasional perforation of the elastica externa” in the Urodela, he is most
emphatic as to the rending asunder and destruction of the chorda (p. 26) during the
formation of the plate in certain Lacertilia. He describes this plate as a septum
of which the cells “‘ retain the appearance of young or embryonic cartilage.” Dealing
with the embryonic Lacerta, he asserts (p. 24) that he is “absolutely certain this so-
called chordal cartilage..... does not exist, if thereby be understood cartilage which
is produced by the conversion of chorda cells; nor does this cartilage invade the
chorda.” His context shows this statement to be based mainly upon the examination
of transverse sections, of which he says that they ‘allow the elastica externa to be
traced as a continuous, unbroken line, which becomes irregularly folded, or creased, as

1 Gegenbaur, C.: Untersuchg. z. vergleichd. Anat. d, Wirbelsiiule b. Amphib. und Rept. 4to. Leipzig,

1862.
VOL. XVI.—PART I. No. 3.—February, 1901. D

18 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

the sections approach the septum” ; and he adds that “the cartilage of the latter is
nowhere in direct contact with the cells of the chorda.” ‘The figures which illustrate
his memoir are unfortunately diagrammatic, but that of a longitudinal section of the
caudal vertebra of an adult Haplodactylus (p. 26), taken conjointly with the descriptive
text and the associated remark that ‘in Phyllodactylus the chorda is only constricted,”
leaves little doubt in our minds that he would regard the chordal plate as ectochordal.
We, on the other hand, are as emphatic to the contrary as concerning Sphenodon },
since we are convinced that in that animal it is endochordal and intimately associated
with the chordal epithelium in origin, as asserted by Gegenbaur.

It first appears at Stage R (PI. II. fig. 11, 2.p.) at the periphery of the chorda, and
entirely within the chordal sheath, which by our method of treatment stains at all
points light yellow as opposed to the blue of the chordal plate. On comparison of
Stage S with R (fig. 11), it will be seen (PI. II. fig. 12) that the plate increases by a
process of inward proliferation. When at S it is worked out in detail in longitudinal
section, two important facts are very evident, which are wholly irreconcilable with the
theory of an ectochordal origin—viz., in the first place, that the tissue of which the plate
is peripherally composed can be traced into continuity with the chordal epithelium,
in a manner which suggests that it arises from this by special activity of its cells; and,
in the second place, that its antero-posterior faces show no sharp line of demarcation
from the substance of the notochord, but rather, on the contrary, a passage into it—the
faces of the plate being irregular, and, as it were, sending prolongations of the matrix
into the chorda (cf. Pl. I. fig. 10). The matrix of the plate is often seen to be feebly
differentiated as its centre is reached, and in median longitudinal section a gradual
transition into the central cells of the chorda may be observed °.

Interesting, in consideration of recent discovery concerning the truncal origin of
the amniote occiput, is the fact that at this stage there is present, wholly within the
central tissues of the chorda (as it were in very testimony to the origin from this of the
plate-tissue), a similar differentiation; and the fact that the distance between it and
the chordal plate of the os odontoideum is about equal (cf. Pl. I. fig. 9, np.) to that
between the latter and the plate next in order of succession behind. is not without
significance. Going back to Stage R, we find this intrachordal mass represented
by an essentially similar, though somewhat irregular, differentiation of the chordal
epithelium, over the whole length of the intracranial notochord (PI. I. fig. 9), with

* Cf. our footnote and reference to Zykoff, on p. 22.

* Dr. Gadow has courteously allowed us to compare his sections with ourown. We can confirm his discovery
of the ectochordal origin of the plates in Lacerta. His sections of Gecko, however, are in complete agreement
with ours of Sphenodon. We conclude that the plates may arise in two independent ways; and we would
accordingly distinguish between the Lacertan type in which they arise by inward extension of the skeletogenous
tissues with accompanying constriction of the cuticular sheath (elastica) and the Gecko-Sphenodon type, in
which they are chordal and lie at all stages within this. A most interesting result, but by no means without
parallel in the animal kingdom.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. ig

accompanying indications of there having been a similar change in the general substance
of the chorda and the adjacent tip of the odontoid vertebra.

The neural arches at this stage call for no special comment. Turning to the inter-
centra, a further suppression of the primary paired series has to be recorded—viz., that
of the bodies related to segments 10 to 12 and 26 to 29, thus giving a condition of
the complete absence of these between and including 10 to 29. With careful focussing
the disappearing primary intercentra (the mode of removal of which we were unable
earlier to determine) can be at this stage observed to lie wholly within the substance
of the skeletogenous tissue (cf. i.p.’, Pl. I. figs. 9 & 10); and by comparison of the
several segments we have convinced ourselves that their disappearance is not due to a
process of absorption and decay, but to one which may best be described as a sharing
in the progressive differentiation of the skeletogenous tissues—/. e¢., there is no loss
of substance, but merely a histological change, leading to a loss of individuality.

On the completion of this remarkable process, the intercentra are present only for the
segments | to 9 and from the 30th backwards, 7. ¢., in precisely those regions in which
in the Lacertilia they are most generally retained; and, as concerning the more precise
limitations of this intercentrumless area, this comparison becomes more close as the
development of Sphenodon advances—until a passing condition is reached in which,
as regards its intercentra, the backbone becomes, as it were, that of a Lacertilian. The
anterior intercentra remain unossified, but it is during this stage that the caudal ones
(chevrons) ossify, and that as the result of a superficial deposit, which in its early con-
dition, as is the case with the neural arches, forms a bony shell (¢f. Pl. II. fig. 13, ¢.p.",
and figs. 4 & 5, na.). Owing to the rapidity with which this process is effected, we
have not been able to ascertain whether ossification arises at more than a single
centre.

Stage T.—The most conspicuous feature of this, the first stage after hatching, is the
great extension of ossification and calcification, with accompanying constriction of
the mid-vertebral areas and a general dawning of the adult characters. ‘The process
of ossification in the centra (ov., Pl. I. fig. 15) has invaded all but the innermost two
to three rows of cells, which are still but calcified ; and it is densest at the point of
greatest constriction. Both within the intervertebral areas (¢.a.) and the central
substance of the chordal plates (n.p.) calcification has become highly conspicuous, and
in the case of the latter it extends into the processes afore-mentioned, which pass into
the chorda-tissue.

The cells of the skeletogenous tissue which mark the boundary-lines between the
intervertebral masses and the vertebree have undergone a complicated rearrangement.
These lines are delimitable by the fact that the nuclei of their cells, which are small,
are vertically disposed in close aggregation, as compared with those of the central
intervertebral series which are larger and run parallel to the longitudinal axis. Those

D2

20 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

of the ends of the vertebrae, which during the earlier stages were structurally uniform
with the cells adjacent, have at this stage become large and rounded, whereby their
matrix is less conspicuous. Once again there are no structures recognizable which

’

merit the term ‘‘intervertebral disks,” nor is there any discontinuity of parts.

At this stage a still further numerical reduction of the primary intercentra goes on,
their disappearance involving segments 5 to 9 and segment 30 (ef. table, column T,
p. 27), leaving only four present in the presacral region and traces of a fifth. The
third, and probably the second and first, at the same time commence to ossify, which
they do endogenously. For certain of the segments which have lost all traces of their
primary intercentra, there now takes place the formation of an entirely new set of parts,
remarkable no less for their time of appearance than for their detailed structure. These,
which arise in relation to segments 9 to 13, appear wholly beneath, though in close
apposition medially with, the interarticular masses (¢.a., Pl. 1. figs. 13, 14), but with
them they have at first no sort of connection. Laterally quite free of them, they lie
between them and a tract of coarse fibrous tissue which (f-t.) besets the ventral face
of the vertebral column. Each of these secondary intercentra stains deep yellow, as
does ordinary bone. The most remarkable character of them, however, is the presence
of a very dark and deeply-staining central portion (éf. fig. 14), which is highly con-
spicuous under a high power of the microscope, and into which there pass convergently
coarse fibres arising from the underlying tissue, which by their refractability are easy of
observation and impart to the bodies a highly distinctive character. These secondary
intercentra are from the first median and transverse, and in this they differ 7 toto
from the primary, which arise in pairs.

Adult Vertebral Aavis——On the anatomy of this we have nothing that is general to
add. Developmentally, the most noteworthy advances, apart from the mere com-
pletion of the vertebral bodies. notochordal plates, and chorda, concern the inter-
articular tracts (which have become more distinctly fibrous) and the intercentra
(which now are finally present along the whole length of the vertebral column). The
tail-vertebree and their special peculiarities will be considered later.

Goette has recently briefly described! the detailed structure of the fully-formed
vertebra of Sphenodon, but that imperfectly, and judging by his figures from apparently
none too well-preserved material. He omits mention of the chordal plate, and describes
the chorda remnant as passing continuously through the vertebre. He further remarks
upon the peculiar constitution of the osseous tissue of the vertebra, which he regards
as “‘no true bone,” but rather to be compared in part to a poorly-celled calcified
cartilage, with enclosed medullary nests, and of an exceptional type for the living
Amniota.

We figure longitudinal sections from the sternal region of the adult backbone,
stained with hematoxylin (PI. I. fig. 15). The intervertebral tissues are now strongly

* Goette, A.: Zeitschr. wiss. Zool. Bd. lxii. 1897, p. 364.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 21

fibrous, and on the ventral side they, together with the subvertebral fibrous tissue (f.t.),
have attained to full differentiation. Their cells are arranged in parallel series, with
an accompanying loss of individuality, the tissues having the appearance of being
permeated by widely-separated parallel rows of small and elongated nuclei. While
peripherally this parallel arrangement becomes more conspicuous, in the deeper layers
the fibres become stronger, their attachments to the bony vertebre appearing more
marked, as the result of their greater avidity for the stain. Owing to the increase in
thickness of the bony shell of the vertebral body (still largely composed throughout
its inner moiety of calcified cartilage), the chordal plates (Pl. I. fig. 15 and text-fig. 4,
n.p.) are comparatively insignificant as compared with the earlier stages. They are,
however, present, and, owing to their completely septate nature, the chorda is now
broken up into a series of elongated and recurrent interseptal segments, each of which
is seen to be bounded not by the chordal epithelium hitherto recognizable, but by a
deeply-staining and structureless cuticle, which passes into the faces of the plates, the
superficial portions of which stain correspondingly with it.

Fig. 4.

Median longitudinal section of the adult vertebral column (caudal region) of Sphenodon, to show the tunica
chordee (t.c.) and its relationships to the chordal sheath and plate. Camera lucida, x70.

i.sg., interseptal segment of chorda; .c.s., chordal sheath; n.p., chordal plate ; 0.v., osseous vertebra ;
t.c. tunica chordee.

This cuticle, which we propose to term the tunica chordw (textefig. 4, t.c.), would
appear to represent the chordal epithelium ; but that it underlies and is independent
of the chordal sheath (nc.s.) is proved by the fact that this stains lightly and can

22 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

therefore be easily traced and seen to be continuous along the whole length of the
vertebral column. We have searched in vain for evidence of the “ occasional breaking-
down” of the cuticular sheath (el. interna) in the vertebral regions as supposed by
Zykoff for Siredon (Bull. Soc. Nat. Moscou, Bd. vii. 1893, p. 34).

“The main cells of the chorda do not undergo any marked change, but in the centre
of each interseptal mass, at the point coincident with that of greatest flexibility,
there has now arisen, apparently by accumulation of a fluid contents, a conspicuous
globular vesicle (Pl. I. fig. 15, v.c.), which we propose to term the vesicula centralis,
and assume to be in some way associated with facilitating the movements of the
parts.

Goette, by an ingenious argument, has drawn the conclusion (op. cit. p. 366),
primarily from the study of the caudal region, that in Sphenodon the vertebre are not
truly amphiceelous. He extends this conclusion with qualification to the trunk-
yertebree, which he figures as transmitting an uninterrupted notochord. Osawa has
adopted his view and applied it to the vertebral column generally (98*. p. 104).
We defer consideration of the caudal region, which is specialized on its own lines, till
later, but acceptation of Goette’s view nevertheless depends entirely upon what we are
to understand by an amphiccelous vertebra. As constituted in many bony fishes, this
type of vertebra, at first sight solid, at its central and most completely constricted
region, is in reality perforated by a minute aperture or canalis dicentralis, for transmission
of a delicate thread-like process of the notochord connecting the adjacent inter-
vertebral masses. If such be termed an amphiccelous vertebra, as is customary, the
mere continuity of this notochord in Sphenodon would be no justification for dis-
regarding the accustomed terminology under which its vertebre are described as
amphiccelous. If, on the other hand, by an amphiccelous vertebra be meant one
centrally solid and with excavated extremities,—/. e., a vertebra of which one or both
articular faces have not become condylar or flattened—then the term may be applied to
Sphenodon, the peculiar characters of its vertebre being in this case the great depth
of its concavities. Inasmuch as we have shown the chordal plates to be notochordal
derivatives, we agree with Goette, in a sense, as to the presence of a continuous
notochord, which on the whole simplifies the customary conception of the Rhyncho-
cephalian vertebra. If, however, for argument’s sake we dismiss the chordal plate
with the rest of the chorda, the characters of the Sphenodon-vertebra become more
nearly comparable to those of the cylindroidal type to which Credner has specially
drawn attention in Palzeohatteria (op. cit. p. 492), which may or may not have been
plate-bearing. Viewed from this standpoint, the extension of Goette’s argument by
Osawa, instead of supporting his defence of the supposed Agamid affinities of
Sphenodon, weakens it to an unexpected degree.

Passing now to the caudal region, the most important facts concerning the

DEVELOPMENT OF THE SKELETON OF THE TUATARA, 23

vertebral axis (apart from outstanding processes and chevrons) lie in the study of the
‘‘splitting” phenomenon and the intervertebral chorda. Since the days of Cuvier,
a good deal of interest has centred in the study of this process, by which the
Lacertilian tail may be cast off. Hyrtl, Gegenbaur, Miiller!, and Leydig have more
especially studied its details, which involve to a conspicuous degree the chordal plate,
as Gegenbaur first pointed out. Gadow has recently summarized our knowledge of
_ the nature and extent of the subdivision-line recognizable on the exterior of the
vertebra capable of “ splitting” among certain Lizards ; and perusal of his statements
will show that as to its position and relationships to the neural arch and transverse
processes variability may be recognized, the “split” subdividing the vertebra in some
cases into equal, in others into unequal portions. In Sphenodon this suture usually
first appears on the caudal vertebree numbering 6 to 8, and it may be present for all
posterior to it. Giinther, who first described it in Sphenodon, states (67. p. 606)
that it ‘“‘ passes through the middle and behind the transverse process,” Gadow, on
the other hand, figures it as passing in front and subdividing the vertebra into
approximately equal halves, of which the posterior bears both transverse processes and
neural spine. With this we are in agreement (cf. Pl. I. fig. 18), but we have noted
that while the suture may occasionally pass through the expanded base of the trans-
verse process *, it may also subdivide the neural spine (as in PI. I. fig. 20) in a manner
anticipatory of the more symmetrical division which, according to Gadow (p. 29,
figs. 22 and 23), appears to involve the anterior neural spine? of Lacerta ocellata.
And further, the characters of the first three suture-bearing vertebre prove conclusively
that although an elongation is effected when the suture is present, it is a subdivision
and not a duplication which has taken place, since in vertebree which are in all other
respects identical with those immediately in front, the suture, which is restricted to
the centrum in nos. 9 and 10, passes gradually up to the arch, assuming the condition
characteristic of those behind.

We have noted that in the adult vertebral column both halves of the splitting
vertebra send down minute but definite autogenous hypophyses, which have not before
been described. These (Aa!', Pl. I. fig. 18), when examined in situ, are found
(fig. 19) to extend into the walls of the hemal canal, to which they act as extra
supports.

1 Miller, H.: Ueber Regeneration d. Wirbelsiule u. d. Riickenmarks b. Triton u. Hidechsen. 4to. Frankfurt,
1864. For other references, see Gadow, op. cit.

2 We consider Cligny in error in his recent argument (“ Miscell. Biologiques,” Travaux d. 1. Station Zool.
d. Wimereux, tom. vii. 1899, p. 482), that the power of fracture and the “ double pleurapophysis” are associated
with ancestral characters. The probability that the centra of the Amniota are compounded of the “ intra-
yentralia ” alone is completely opposed to it.

2 §o called by Cope in Dipsosaurus and Sauromalus, Proc. Amer. Phil. Soc. vol. xxx. 1892, pp. 202-205.
Comparison with Sphenodon renders it extremely doubtful if this is a product of division, as assumed by
Boulenger (P. Z. 8S. 1891, p. 169). We would rather regard it as a secondarily formed outgrowth like the
autogenous hypapophyses which we herein describe.

24 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

Equally significant, as proving that the splitting phenomenon is secondary, is the
fact, already pointed out by Gegenbaur in 1864, that the changes which render it
possible appear as, by ossification, the vertebra is assuming the adult condition ; and in
support of this we are able to state that the bony centrum and chordal plate (both of
which become split as the adult condition is realized) are in the developmental stages
complete. The first appearance of subdivision is at Stage 'T. In fortunate sections of
the adult we have been able to determine the probable method of splitting, and that it
is, at least to a large extent, due to invasion of the bony vertebra and ultimately of the
chordal plate itself (cf. np., Pl. I. fig. 17) by the surrounding tissues, with accompanying
absorption, since in sections in which the process was going on we find an inward
extension of these tissues into the parts already ossified, with an accompanying peri-
vertebral striation radiating from the split (cf. Pl. I. fig. 17,7.) such as we have
encountered nowhere else. The bony vertebrae, however, continue to thicken after the
first appearance of the split, and nowhere more so than at its opposite edges ; wherefore
it follows that by this, which is a growth process, the split is extended outwards.

We find in the intervertebral regions of the tail that a series of changes of a some-
what remarkable and intensely interesting order are undergone. Goette has recently
described them in part. He calls attention (op. cit. p. 365) to the fact that in the
caudal region the opposite ends of the vertebre, which in the trunk are usually directed
outwards, are inwardly thickened, and that they so constrict the vertebral canal that it
is most spacious within the vertebra and narrowest at its extremities. In this respect
the caudal vertebra presents a striking contrast with that of the trunk-region, in which
the ends are widely open and the centre is contracted. He asserts that correlatively
with this constriction an ingrowth of the intervertebral mass, already foreshadowed in
the trunk-region, has effected a complete blocking of the intervertebral area, with
accompanying segmentation of the chorda. When first examined, the intervertebral
regions of the tail of a mature Sphenodon do appear to be compact, as Goette asserts ;
but when further investigated in well-preserved material the parts there present are
seen to be complex, and to bear to one another a relationship essentially similar to that
which the chordal plate bears intracentrally to the vertebral body. ‘The interseptal
chordal segment (PI. I. fig. 17, ¢.sg.) becomes divided throughout its intervertebral region
by a cartilaginous plate (n.p.’) lying wholly within the chordal sheath, continuous with the
tunica chord, and having essentially the same structure and evidently the same origin
as the chordal plate (m.p.). Indeed, the first indications of this are met with at Stage T,
as a well-marked thickening of the tunica chord and its associated cellular tissue.
As fully differentiated, this, which we propose to term the intervertebral chordal plate,
in contradistinction to the chordal plate which is intravertebral, reveals terminal calci-
fications, and a centrally less dense area at the point where movement of the parts
is greatest, which, while providing for the necessary flexibility, furnishes additional
support. It would thus appear that under the weakening influence associated with the

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 25

splitting of the strongest part of the vertebral complex, a compensating development is
deliberately initiated in the intervertebral—a process to which the term of Dohrn
and Kleinenberg, “substitution of organs,” may be not inappropriately applied; and
beyond the extent to which these intervertebral plates may furnish support and be
concerned in determining points of muscular attachment, we are inclined to regard the
intravertebral plates as direct agents in the formation of the axis of the reproduced
tal. This matter, however, requires further investigation. There remain only for
consideration the definitive intercentra of the region of disappearance of those of
the primary series, viz. segments 5(?)-6 to 30. The intervertebral region of each of
these shows an intercentrum of considerable proportions (PI. I. fig. 15, 7.s.). This, the
secondary intercentrum, agrees with those already described (antea, p. 20) in lying
outside the skeletogenous tissues, as figured by Goette (op. cit. pl. xvii. fig. 25, 2).
Not wholly so, however! ‘The most distinctive character of these remarkable bodies is
a sharp demarcation into a greater feebly-staining outer portion and a lesser inner one,
which differentiates darkly and, when viewed in section, tapers into the intervertebral
mass. The cells of their inner moiety are more numerous and much larger than those
of their outer; and since in the mode of disposition these are linear with those of
the intervertebral mass, they would appear to be derived from it. If this be so, these
definitive secondary intercentra would appear to represent those to which we originally
applied the term, but with a superaddition of parts derived from the intervertebral
tissues. Be this as it may, their formation finally completes the series of inter-
centra, which are now present throughout the whole length of the column.

Typically these secondary intercentra arise singly, as median and transverse masses.
In one case, however (i.s., Pl. I. fig. 16), we have noted that for segments 12, 13, and
16 to 20 (7 in all) they are paired. Boulenger has drawn attention (P. Z.S. 1891, p. 170)
to the existence in Lacerta ocellata of paired intercentra in the posterior sacral and
anterior caudal regions, and Leydig has figured a similarly-paired condition of one of
the preesternal intercentra of L. agilis (op. cit. pl. iv. fig. 53). In the absence of any
knowledge of secondary intercentra in the Lacertilia, we conclude that while in both
species the paired elements are of primary order, in our exceptional Sphenodon
those of the post-sternal region, which are paired, would seem to be of secondary,
and that these may therefore be variable as to their median or paired nature.

Comparison of the caudal region of Sphenodon with that of Lacerta ocellata as
described by Boulenger would seem to justify the conclusion that in the chevrons
primary intercentra are alone represented. We find, however, that in the case of the
first 4-5 this isnot wholly so. In the adult Sphenodon, these are characterized by the
fact that their proximal ends are united, as pointed out by Dollo in 1883 °, whereby
they appear to overarch the caudal canal. Credner has confirmed this observation, and

‘ Dollo: Bull. Mus, Hist. Nat. Belg. tom. ii. 1883, p, 324.
voL. Xvi.—part 1. No. 4.—Mebruary, 1901. E

26 PROF. G. B. HOWES AND MR, H. H. SWINNERTON ON THE

a

with equal acumen has made it the basis (op. cit. p. 901) of determination of the
isolated chevrons of Palwohatteria as median caudal.

Seeking the explanation of this overarching in Sphenodon, it occurred to us, having
proved the chevrons proper to be permanent primary intercentra, that their united
“proximal ends,” being serial with our secondary intercentra, may be the homologues of
those and that the anterior 4-5 chevons are therefore complex}. In support of this con-
clusion we would point out that at those stages at which the secondary intercentra are
undeveloped (PI. I. fig. 12 and PI. II. fig. 13) the extremities of the chevrons in question
are in no way united; and proof of its accuracy has come to us in a specimen belonging
to the Dublin Museum, in which (PI. I. fig. 21) the right half of the anterior chevron
(i.p.") and the overarching lobe (our secondary intercentrum) have remained distinct.

We append, in tabular form (p. 27), a synopsis of the complicated series of changes
undergone by the successively formed sets of intercentra; and in conclusion desire
once again to emphasize the fact that in the most fully differentiated state the bony
vertebre and the fibro-cartilaginous interarticular masses of Sphenodon are organically
continuous.

We are constrained to do this as Cope more particularly °, and Gadow, though with
greater caution 3 (reading as we believe theory and expectation into fact), have referred
to the intervertebral masses in terms applicable only to discontinuous skeletal parts.

The so-called “ Pro-atlas.’—The most recent view expressed as to the morphology of
these debateable elements is that of Gadow, who (op. cit. pp. 12, 15, and 57) has come
to regard them as parts of the atlas—the serial homologues of his “* supradorsalia ” of
the supposed ancestrally composite vertebra. In the conclusion that the atlas was
thus originally more complex than has hitherto been supposed, and that the atlas and
‘‘pro-atlas ” represent one vertebra, he has been followed by Osborn (op. cié. p. 173),
who, from the study of the paleontology of the Reptilia, has come to regard the atlas
as composed of five pieces and “ persistently rhachitomous.” Despite all attempts to
discover facts which might help further to elucidate this question, we have failed.
Appeal to the nerves availed us nothing, and all that we can add is that the “ pro-
atlas ” so-called is preformed in paired cartilages (PI. II. fig. 3, p.a.), which at Stage Q
arise independently of both the cranium and the rest of the vertebral column, and are
imbedded in the tendons of the dorsal skeletal muscles, near the point of attachment
of these to the exoccipital, and that their articulation upon the skull is secondarily
acquired (cf. Howes, 90, p. 357).

! We fully concur in Boulenger’s refutation (Ann. & Mag. Nat. Hist. ser. 6, vol. xii. 1893, p. 60) of Dollo’s
hypothesis that “ hsemapophyses are homologous in all Vertebrata.”

* Cope, E. D.: Trans. Americ. Philos. Soc. yol. xvi. 1886, p. 248.

5 Gadow, H.: Phil. Trans. vol. 187 B. (1896), pp. 33 & 51. The term “intervertebral disks” is apt to
create the impression of existence of independent elements.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. sith
| 12, Q. R. s. oe, Adult
| ae ea pa feed [eee EN
ih, ? U. (Of, Uz. (Of, U~.
2 ? U. U~. U~. U~L Uv.
as 3. I, U. U. U. U~7 U.
Ss 4. 122, Uz. U. U. UL U~.
is 5. 12: U.T Uz U. 2? ?
| & 6. IP (ESP WE Uz. —— F.
Uo IB. Ont U~. U~. — | PF.
8. 12. U.¥ Uz. U~. — F.
9: 12 Uz. U. U~. F. Ti.
10. 12, U~. U~. — F. F,
15, Je}, (Df, im — F, Hs
late IB Uz. 2 = F. F.
13. P. U~. — — F. Hs
14, Pp iz — — — F.
15. 12. ID, = — — F.
[a AG 12, BI — — — F.
| = 17. Ii Iz, — — = F.
fs ea 18. 12 IB, — — F.
| 119), IB. IZ — — F,
| 20. 12 12, — — 18,
| PAG IP: JB, a= — F.
22, IB. 2. — — F.
23, IB. IP, = — F,
| 24" IB IPS — — F.
25 12. Ps ss — — F,
5 26. B: 12. ? = = F.
| a Ale PR: 12. ? a — FB,
__——— sulle bree Wee ee || ee
28. iP 2 ? = — F.
29. PR. I, ? = — F,
= 30. IP, 12 IP, IP. — Ig
S Bills Jee Py Chev. Chev. Chev. Chev.—F.
EB 32. PB. 1P2, Chev. Chev. Chev. Chev.—F.
= 33. P! P. Chev. | Chev. | Chev. | Chev.—F.
34. IR. 2 Chev. | Chev. Chev. Chev.—F. |
| 35. I, iP Chev. Chev. Chev. Chev.
Y | Y ¥ ¥v ¥ ¥
|

Fig. 5.—Tabular statement of the order of arrangement and succession of intercentra for
Stages P to T and the adult.

P. Primary paired iutercentra. U. Unpaired intercentra of primary order. — Intercentra absent.
F. Secondary intercentra. Chev. Chevrons. + Medially constricted.

Ribs and Sternum.—Ribs were attributed by Giinther to the segments between and
including the fourth presternal (cervical) and the second sacral. Discriminating
between the osseous rib as a “‘ pleuropophysis ” and its unossified ventral portion as a
‘“‘hemapophysis,” he further distinguished between those vertebre in which the latter
is fully developed as “dorsal” and those in which it is reduced as “cervical” and
‘‘lumbar ” respectively.

For the caudal region he describes the presence of “transverse processes” and

E 2

28 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

rightly records a transverse disposition of the first and second and the forwardly-directed
one of those which follow (doc. cit. p. 606). In attributing the first cervical rib to the
fourth vertebra he was in agreement with Owen, who first discovered this}. Baur,
however, later described in an individual specimen the presence of a free rib upon the
third vertebra, and showed at the same time that (86°. p. 736) the so-called caudal

?

“transverse processes” of the adult represent co-ossified ribs. Osawa (98% p. 485)
declares his inability to confirm the presence of the latter; but, with Gadow, we can
do so, and can confirm the occasional presence of a rib to the third preesternal vertebra.
Neither Gadow nor Baur state the number of caudal ribs observed. Our own investi-
gation shows them to be present (Pl. I. fig. 12) for at least the eight anterior caudal
vertebra. Posteriorly to these, according to Gimther, the “transverse processes”
become rudimentary, and we have no material to prove whether they do or do not
ossify separately. The osseous rib-formula may accordingly now be rendered as
follows, allowing for the possible presence of additional caudal ribs yet to be
discovered :—

iPreestenal eeeneer eee eer rer 5-6

Sternall (ieee 3-4

iPoststexnall Gaeeeeeeeene reer 13-14

Sacralin nissan eee 2 with variation.

Caudaly esaecceeeeee 8 observed at Stage S.
Average ...... 33

In the adult animal the anterior presternal ribs alone stand related to both inter-
vertebral and vertebral bodies (¢f. Pl. II. figs. 1 & 2), the rest either articulating or, as
in the case of the caudal and apparently in individual cases of the last three post-
sternal, becoming co-ossified with the vertebre alone. Baur, in describing the pre-
sternal ribs, has drawn attention to the existence of supposed ligamentous homologues
in relation to the first and second vertebral segments, and to the third where an osseous
rib is absent. Of these ligaments, he describes the first as single-headed and attached
to the first intercentrum, the second and third as double-headed and attached to both
intercentrum and transverse process of their corresponding vertebre (7. ¢. those behind),
and he points out that in its attachment to the intervertebral body the lower liga-
mentous tract agrees with the capitulum of the rib borne upon the fourth vertebra,
which he, with Owen and Giinther, describes as two-headed. Of the fifth rib, he
rightly points out that it is the capitulum which is reduced, wherefore it follows that if
his identification of these ligamentous tracts as vestigial ribs is correct, the first and
fifth are diversely modified.

We can confirm (cf. Pl. Il. fig. 2) the general accuracy of his description and

" Owen, R.: Cat. Osteol. Series R. Coll. Surgeons Mus, vol. i. 1853, p. 142.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 29

can extend his discovery of an osseous rib for the third vertebra to an individual of
Dendy’s Stage S (PI. I. fig. 1) and to adult specimens in the R. College of Surgeons
and British Museum. If his “ ligamentous ribs” are really such, it is reasonable to
suspect that at some developmental stage they may be either definitely skeletogenous
or may show traces of their supposed skeletal origin. After careful search, we are only
able in support of this conclusion to point to the existence within the third ligament
of an individual of Stage S of an insignificant cartilaginous nodule. ‘The fact that no
trace of a corresponding nodule was forthcoming in the two specimens of Stage R
examined, leads us to regard the afore-mentioned case as an individual one of the
presence of a vestigial rib.

Concerning the relationships of these supposed ligamentous ribs, there is a detail
not recorded by Baur. As viewed at first sight (fig. 2), the double attachment would
seem suggestive of a two-headed rib; but, in the case of the most distinctly two-
headed osseous rib (viz., that of the fourth presternal segment), the osseous capitulum
and the supposed ligamentous one coexist, while for both this rib and those behind it,
in which the capitulum is unrepresented in bone, the supposed ligamentous portion of
the rib, instead of passing into the substance of the osseous one, as should be the case
were it a constituent of the rib, merely skirts the lower border of that with an
accompanying attachment of its fibres. ‘Throughout the region of insertion anteriorly
of the muscles termed by Osawa “ costo-cervical,” it leaves the rib and passes on as an
independent structure, in the manner delineated in PI. II. fig. 2, m.’-—in exactly the
manner which would result from an intimacy of mechanical relationship. When to
this is added the disproportionate development of the first of the so-called “ liga-
mentous ribs,” which is in reality for the most part a muscular mass, we doubt how
far these structures really represent ribs wholly or in part, and confess ourselves
unable to definitely decide the question either way’.

Turning now to the rest of the presacral ribs, as concerning their heads and
articulations alone, we find as we pass back from the fifth cervical the distinction
between tuberculum and capitulum becomes gradually lost. With this simplification
there takes place a reduction of the transverse process, which, never strong, disappears
in the anterior sternal region, and, as pointed out by Osawa (98*. p. 735), is formed by

1 At the outset of our investigation into the “cervical” region, mindful of the belief in the Chelonian
affinity of Sphenodon and the assertion by W. K. Parker (‘ Challenger’ Reports, Zoology, vol. i. pp. 47 & 50)
that in the embryo of the Green Turtle the somatomes of the neck and tail are more numerous than later, and
undergo numerical reduction by abortion, we kept a look-out, in vain, for probable evidence of a similar
process, so far as it might involve the skeleton in Sphenodon, in the hope of being able to obtain some clue
to the meaning of the numerical variation of the reptilian prasternal segments so conspicuous among the
Dolichosauria and Mosasauria. From the discovery of facts concerning the variation in relationship of the
sternum which we herein describe (infra, p. 34), we are disposed to regard numerical variation among the
presternal vertebree, if not the poststernal also, as associated rather with a shifting of the sternum than an

excalation of segments, as Parker’s allegation would seem to suggest.

5) PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

both the centrum and the arch. Giinther describes the heads of the ribs as “low and
compressed,” and attributes to them a wholly central articulation. Baur has more
correctly shown (86. p. 735) that the connection is rather with the arch, but he never-
theless insists that ‘‘in reality the rib never completely forsakes the centrum.”

We can confirm the details of Baur’s description and extend them to Stage S.

Of the so-called “lumbar” ribs, 7. e., the posterior two to four of the presacral
series, the head of the last one may show increased expansion, and in this way that
may become in a sense transitional to the sacral rib, the special feature of which
(PL. Il. fig. 5, 7.s.) is its general robustness and greater attachment to the centrum.
Except to point out that the sacral ribs are ossified in the manner of the presacral
(Pl. IL., cf: figs. 4 & 5), we have nothing to add te recorded descriptions concerning
them. ‘There are usually two pairs, of which the anterior are the more slender and
transversely disposed, the posterior the more robust and forwardly directed (Pla
tig. 12, 7.s.). The iliac articulation is usually furnished by their united outer carti-

laginous extremities.

Sacrum with hip-girdle of an adult Sphenodon, bearing on the left side an abnormal set of ribs.

¢.a., articular cartilage ; é7., ilium ; és., ischium ; pb., pubis; 7.cd.’, first caudal rib ;
7.8.', 7.8., sacral ribs. Nat. size.

In view of the frequent existence of three sacral ribs in many living Lacertilia 1, of
more than two in the Chelonia, of the occasional presence of a third in recent Cro-
codilia*, and particularly of that of at fewest three pairs in Paleohatteria®, interest.
attaches to a skeleton preserved in the Dublin Museum of an adult Sphenodon (text-
fig. 6) having on the left side a trisegmental sacrum, on the right a sacrum and hip-
girdle normal in all respects. The third sacral rib on the left (r.cd.1) is seen to be the
first caudal, enlarged and expanded. Externally it was in life continuous by its outer

* Stellio and Chamieleo, Credner, H.: op. cit. p. 505. Phrynocephalus, Cope, E. D.: Proc. Amer. Philos.
Soc. vol. xxx 1892, p. 207. For other examples cf. Siebenrock, F.: Ann, naturhist. Hofmus. Wien, Bd. vii.
p. 373, and Sitzb. Akad. Wiss. Wien, Bd. civ. p. 67,

* Baur, G.: Zoolog. Anz. Bd. xii. 1889, p. 240.

* Credner, H. op. cit. p. 505.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 31

cartilaginous border with that of the second sacral rib. This was stouter than usual,
while the first rib, reduced externally to a degree proportionate to the extension of the
first caudal into the sacrum, was reduced to the calibre of a presacral rib. The
combined cartilaginous heads of the three ribs, by union, furnished the iliac articulation,
and there can be no doubt that the determining cause of this abnormality was the
backward rotation of the left ilium, well marked. It may be a case of ‘ vertebral
assimilation ” !, but its interest is none the less if so.

We have only to add, concerning the caudal region, that at Stage S, when ossification
is setting in, the detailed relationships of the caudal rib to its centrum and arch are
closely identical with those of the sacral vertebre (cf. Pl. II. figs. 5 & 6), and that at
this stage comparison with the presternal region (fig. 4) shows that the interarticular
tissue between the rib and its vertebra is far less differentiated than there.

The most conspicuous difference recognizable on a survey of the whole series of rib-
heads in the adult and the later developmental stages of Sphenodon, is the fact that
while the individual rib is for the most part obliquely attached or articulated upon the
anterior end of its related centrum, in the case of the third and fourth presternal ribs,
which are two-headed, this antero-ventral extension is more marked and involves the
intercentrum, the capitular head abutting against that. For this an explanation has to
be sought.

Examination of the posterior trunk, sacral, and tail vertebra, at the period of
chondrification, would seem to indicate (cf. figs.) that the ribs arise only in relation to
the vertebral bodies, and that they may be derivative of either their arch system, as
originally believed for the higher Vertebrata by Gegenbaur, Goette, and others ; or of
their transverse processes, as argued by Claus, and more recently by Corning? and
others—z. ¢., that in any case they would appear to be vertebral in origin, as has been
more recently maintained for the ribs of the Vertebrata generally by Dollo 3. Hofmann,
in a memorable paper published in 1878 4, from the study of both the anatomy and
development of adequate representatives of all the amniote classes but birds, deduced
the final conclusion that the ribs of these animals are primarily intervertebral. Baur
has further sought to support this view ®, and Gadow, among most recent investigators,
has done likewise, in his final conclusion (96. p. 50) that the ribs of the Amniota are
lateral outgrowths and the chevrons and hemapophyses ventral outgrowths of his
‘‘basiventralia,” which give rise to the intercentra °.

1 Of. Siebenrock, F.: Ann. naturhist. Hofmus. Wien, Bd, vii. 1892, p. 373.

* Corning, H. K.: Morph. Jahrb. Bd. xvii. 1891, p. 611; cf. also Goeppert, ibid. Bd. xxv. 1897, p. 247.

3 Dollo, L.: Bull. Sci. Fr. & Belg. tom. xxiv. 1892, p. 113. For other references, see Hofmann, infra.

* Hofmann, C. K.: Niederld. Archiv, Bd. iv. 1878, p. 199.

° Baur, G.: Amer. Nat. vol. xxi. 1887, p. 942.

® Psychologically interesting in this association is the conclusion of Dollo (op. cit. p. 128), who, though
apparently in error concerning the vertebral origin, regards the “ ribs ” as dorsal ribs, the * heemapophyses ’
as yentral,

32 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

On examination of transverse sections through the developing vertebral column
of Sphenodon at Stage P, at which the parts of the cartilaginous vertebree are as yet
undifferentiated, the tissue giving rise (Pl. I. figs. 5 & 4) to the paired intercentra
(i.p.')—which, it will be remembered, are the first, and at this stage the only components
of the vertebral column recognizable—is seen to be continuous with that differentiating
into the ribs (7.cd.). Figs. 5 and 4 represent the first and sixth sections across an
individual caudal segment; and comparison of those which intervene has shown us
that even here, when the vertebral body is not yet differentiated, the disposition of the
proximal end of the rib is oblique, involving ventrally and anteriorly the intercentrum,
dorsally and posteriorly the region of the future centrum and arch. Comparison with
the adult cervical rib reveals a close similarity of relationship; and since with later
development the connection with the intercentrum is lost, the primary relationship of
the rib is proved to be intervertebral.

Cope in 1878 first drew attention ! to the existence in certain Permian Pelycosauria
of a two-headed condition of the rib, with accompanying intercentral articulation of
the capitulum; and Baur, eight years later, in his afore-mentioned paper on the
cervical ribs of Sphenodon (prompted by Cope’s announcement), sought to emphasize
the importance of this. Cope, immediately afterwards, in dealing with the structural
resemblances between these creatures, prompted by Hofmann’s brilliant generalization
afore-mentioned, penned the remarkable paragraph?: ‘The passage of time has
seen in the Reptilia generally ” a modification ‘in the mode of attachment of the
rib,” in which, “in passing from front to back, the intercentral articulation is
lost, and finally the head of the rib disappears.” ‘The facts we have just described
render this well-nigh prophetic; and it remains to be ascertained how far the sup-
position, deduced from the study of longitudinal sections alone, that the ribs of the
Amniota, and of the Reptilia in particular, arise in exclusive relationship to the
transverse process, centrum, or arch, will stand the test of examination in other
planes, and, as deduced from that of developmental stages at which chondrification
is more or less advanced, will bear further comparison with the earlier ones of pro-
cartilage differentiation. ;

Concerning the bodies of the ribs, we have nothing to add to the descriptions
of Ginther, Maurer (96), Osawa, and others, except as regarding the so-called
“uncinate processes.” Giinther in his original description accords the first of these to
the last presternal rib, Osawa to the penultimate, but neither state their posterior
limitations. Like those of the Ratite birds, they are apt to be easily lost in maceration ;
but in carefully prepared specimens we have been able to trace them back, with

* Cope, E, D.: Proc. Amer. Philos. Soc. vol. xvii. 1878, pp. 518 ct seg.; and Proc. Amer. Assoc. Ady. Sci.
1884, pt. i. p. 474.
* Cope, E. D.: Trans. Amer. Philos. Soc. vol. xvi. 1886, p. 249.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 35

progressive diminution in length, to the 11th—-12th poststernal rib. They are longest
throughout the middle of the series, and they arise late at Stage Q, after the ribs have
become chondrified, by independent concentration of the cells which go to form the
intermuscular septa. They also chondrify independently at Stage R (PI. II. fig. 7,
u.p.), at which the ribs are well ossified. Jeffery Parker has already called attention !
to their similar independence in Apteryx, and we accordingly follow him in the usage
of the term wncinates.

There can be no doubt that the process borne by the last preesternal rib is a true
uncinate, since our sections at Stages Q and R reveal its independent origin. We
find that the “process” borne by the penultimate rib, which Gtnther (67. p. 607)
believed to be homologous with the uncinates and which Osawa definitely refers to
them, may by elongation assume the size and shape of one in its most pronounced
form, as contrasted with its condition described by Gtinther of a mere “dilated
heemapophysis.” On the study of this he was led to regard the uncinates as
hemapophysial in origin, “separate and removed from the distal end of the pleur-
apophyses as the latter increase in length.” At our Stage R, at which the ribs are
beginning to ossify and the uncinates proper are still distinct from them, the penulti-
mate rib and its supposed uncinate are continuous, while a similar but feebly developed
process is present on the antepenultimate rib. At the period of continuity, the
penultimate rib and process may in some sections present appearances suggestive of a
possible precocious union; but, inasmuch as we are unable definitely to detect
its presence at an earlier stage or in a wholly free state, we leave it an open question
whether the ‘‘ process” may or may not be a mere outgrowth of the cartilaginous rib.
If the non-extension of the osseous rib into the uncinate zone be due to loss of connec-
tion with the sternum, the former conclusion would be the more likely; if, on the
contrary, it be not so, it may well be that, under the extension of the unossified moiety
into the zone, the plastic cartilage has been seized upon as available for extension and
support under the mechanical conditions at work.

The Sternum.—By way of descriptive detail, of the adult sternum we have nothing to
add to the statements of Giinther and Osawa, except to state that neither has recorded
the fact that even in the adult its posterior border is notched. At Stages R and T this
notch (Pl. VI. figs. 5 & 6, s.v.) is very conspicuous, and inasmuch as at Stage Q the
two halves of the sternum are widely separated, the question arises whether or not the
notched region is one of non-union of its opposite halves.

Parker, in describing the developing sternum of Apteryx, in the adult of which
there are four pairs of sternal ribs, has shown 2 that the two anterior of these apparently
give rise to the sternum, and that the connection of this with the two posterior is
secondary and due to extension of both sternum and ribs. In Sphenodon three pairs

1 Parker, T. J.: Phil. Trans. 1891 B, p. 80.

2 Parker, T. J.: op. cit. of. pp. 87 & 118.

VOL. XvI.—ParT 1. No. 5.—February, 1901. F

34 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

of sternal ribs have been hitherto described for the adult, but we find that four pairs may
be present, as, for example, in a skeleton in the Teaching Collection of the R. College
of Science, Dublin. Similarly, in the developmental stages, four pairs may occur, as at
Pl. VI. fig. 6 (Stage T), or four on the left side only, as at Pl. VI. fig. 5, or on the
right, as in specimens of Stage S in our possession.

The earliest developmental stage of the sternum we have observed is at Q. In the
section of this figured (Pl. VI. fig. 4) but two ribs are seen to contribute to the
sternum, but examination of serially related sections proves that the third enters also
into its formation; and, from what we have seen, we incline to the belief that when
a fourth is present it also has contributed.

In the latest stage figured, the organic continuity between ribs and sternum is still
uninterrupted, the ‘“ incisurz coste ” being of late origin. As early as Stage R the
sulcus coracoideus (cor.') is well indicated, and anteriorly the sternal plate is prolonged
into a couple of episternal cornua, which skirt the stem of the interclavicle and
contribute to the formation of the sulcus, in a manner which holds good for the adult,
but has been inadequately recognized in all previous descriptions.

In the specimen from the Dublin Museum, this last right preesternal rib reaches
the sternum, and its cartilaginous segment, by elongation and enlargement, has the
characters of a normal sternal member. Its osseous segment is normal, and there are
no accompanying changes recognizable in the ribs in front of it. We have already
adverted to one point of interest attaching to this specimen (antea, p. 30); and if, as
there is reason to believe from what is known of the Mesozoic reptiles, the amniote
sternum in its ancestral condition, in which it was most certainly cartilaginous, was
more extensive than its more specialized homologue of the living forms !, fluctuation
anteriorly and posteriorly such as we have recorded becomes the more readily
intelligible.

There are no indications of any elements, median or otherwise, entering into
the composition of the sternum, beyond those derivative of the ventral extremities
of the ribs.

The “ Abdominal Ribs” (Gastralia?).

These are in number 22 to 26, and they are alternately attached to the ventral
segments of the poststernal ribs and free, at any rate for the most part, as originally
pointed out by Giinther. Osawa records 24, of which he remarks the first is attached
to the first poststernal rib (98. p. 491), as are those behind corresponding to odd
numbers, back to the 21st. The 22nd, 23rd, and 24th, with those corresponding to even
numbers, he describes as free. We find, however, that regarding the first point there

* Osborn has described fossil an expanded cartilaginous sternum arising from ten pairs of ribs in the
Mosasaur Tylosaurus dyspelor (op. cit. [antea, p. 14] p. 180).
* Baur, G.; Anat, Anz. Bd. xiv. 1897, p. 150.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. BYS)

is considerable variation. Boulenger has called attention! to the fact that “the
anterior extremity of the plastron overlaps the posterior extremity of the sternum,” and
concerning this, two specimens we have examined yield interesting results. In each of
them there are two free gastralia in front of the first that is attached to the ribs; and
while in one example (that possessed of four pairs of sternal ribs) these are short and
median, in the other (that in which the last “cervical” rib is sternal) the anterior
gastralium is represented by a symmetrically-arranged pair of rods.

Ginther originally described each gastralium as of three elements, and their natural
relations are generally those indicated in Pl. II. fig. 10, no.7. Not unfrequently union
in the middle line, as figured and described by him, may occur, and it would seem to
involve a forwardly-directed spur on the median element which is generally present
(cf. Pl. II. fig. 10, no. 11). Much interest attaches to Giinther’s description of an
exceptional specimen, in which for the rib-connected gastralia the lateral elements were
attached to the central by transverse “ joints,” instead of being in oblique juxtaposition
with them as for the free gastralia and as is more generally the case throughout the
entire series. The fact that, in most specimens we have examined, individual gastralia
of both the attached and free order show both “ jointing” and juxtaposition, and that
while in most cases one or two such “joints” may be present only on one side——there
being no regularity recognizable,—proves that no physiological significance is to be
attached to these variations.

Turning to the embryo, we find that the gastralia arise at Stage S, within previously
differentiated fibrous tracts of the subcutaneous tissues of the body-wall (g.¢., Pl. I.
fig. 9), by a process of calcareous deposition, which proves them to be wholly
membranous in origin. ‘Their connection with the myocommata of the body-wall is
fully established later, and with Gadow? we have failed to detect any traces of a
cartilaginous origin, believed by Schneider to be the case for the Crocodilia. Figs. 8
and 9 represent (8) the anterior (third to fifth), 9 the posterior (16th to 18th and more
highly magnified) gastralia of an example at Stage S. It will be observed that the
median element is present only anteriorly, and that while for two of the three segments
figured comparison with the adult shows its lateral cornua to be partly represented by
a series of minute calcifications, for the anterior segment it is composed of two pieces.
Anteriorly the lateral elements are seen to be fully formed, but on passing to the posterior
series two of the three figured are observed to be represented by a linear series of
distinct calcifications, the median element being undeveloped. The fact that in the
adult the gastralia which occupy the positions of those here figured are alike
symmetrical and only trisegmental, proves that with advancing development a union of
the calcifications such as are here figured must occur, and that the median elements

’ Boulenger, G. A.: Brit. Mus. Cat. Chelonia, Rhynchoceph. & Emydos, 1889, p. 1.
2 Gadow, H.: Morphol. Jahrb. Bd. vii. 1882, p. 77.
F2

36 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

a)

arise antero-posteriorly. It further indicates a compound origin for all the parts, median
and paired alike ; and concerning the anterior paired segments, which in the individual
figured were single, we find that in younger individuals at the same stage they may be
represented by a series of elements. The details point to the conclusion that union is
rapid and irregular.

A striking characteristic is this irregularity of calcification! It leads to irregularity
of union; and it is fair to assume that in this lies the explanation of the asymmetry
which the parts of the adult “plastron” are apt to assume. It explains the not
infrequent presence of but a single asymmetric element, and of so extraordinary
a condition as that of the triradiate or quadriradiate union delineated on Pl. IL
fig. 10 (Stage T)—the most erratic we have observed. It also renders clear the sub-
stitution of transverse “joints” between, for oblique juxtaposition of, the median and
lateral elements described by Giinther, and the co-existence of these herein recorded,
while it presupposes other combinations yet to be discovered.

Interesting and unexpected as are these details ontogenetically, we have come to
attach a still greater importance to their probable phylogenetic significance.

One of the most distinctive characters of Credner’s Paleohatteria of the Permian is
the multisegmented condition of its ‘abdominal ribs,” which, on careful examination of
the originals, he has shown to be also the condition in Von Meyer’s famous Protero-
saurus and other genera to which he refers (op. cit. p. 538). In view of the obvious
similarity to the embryo Sphenodon suggested, it becomes the more interesting to find
that whereas in Palzohatteria, according to Credner’s original description, there appear
to have been three rows of calcifications present for each rib, in Proterosaurus there
were two or three. In a later paper, however, on Kadaliosaurus, an allied genus, he
gives! the number of “abdominal ribs” as regularly six for each vertebral segment
possessed of them ; and in instituting comparisons with Paleohatteria, Proterosaurus,
Stereosternum, and Hyperodapedon, he gives the number present in them collectively
as from three to six. The calcifications in all these forms are regular and structurally
constant, whereas in Sphenodon they are developmentally irregular and inconstant.

Kadaliosaurus is further interesting in the light of the foregoing observations upon
the substernal extension of the “ gastralia” in Sphenodon, as in it they are still more
nearly pectoral in extent and Stegocephalian. The facts suggest that the “ plastron ”
may be undergoing reduction in the living genus, a consideration which may perhaps
explain the irregular mode of calcification by which it is formed.

Boulenger, availing himself of these facts of paleontology, has made them a basis
of classification of the Rhynchocephalian Order to which we alluded at the outset
(antea, p. 3), and he has drawn a sharp distinction between the higher suborder
of the Rhynchocephalia vera (91. p. 171) (Hatteriide, Homeosauride, Rhynchosauride,

* Credner, H.: Zeitschr, deutsch. geolog. Gesellsch. Bd. xli. 1889, p. 330.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 37

and Sauranodontide), characterized by the triserial condition of the ‘“ abdominal
ribs,” and the lower or Proterosauria (Paleohatteriide, Proterosauride, and Champso-
sauride), in which their segmentation is multiserial. The adult Sphenodon, if
classified by its “plastron,” can only be referred to the former—the developing
Sphenodon might with justice be relegated to the latter and lower suborder! In this,
Boulenger’s far-sighted classification receives welcome support.

Moreover, the multisegmented condition of the “plastron” segments is nothing
short of a Stegocephalian character.

The Skull and Visceral Arches.

In compliance with passing custom, we have adopted in this section of our work the
reconstructional method, as before stated (antea, p. 7).

Beyond the memoirs of the late Kitchen Parker, and some recent preliminary notes
by Gaupp, together with the observations of Leydig (op. cit.), Born, and Hofmann, duly
mentioned by him, little has been written upon the actual development of the
Lacertilian chondrocranium!; and since in the absence of figures we find it difficult
to follow the details of Gaupp’s descriptions, we deem it more prudent to describe
connectedly the processes taking place in Sphenodon, which are simple and straight-
forward, and highly instructive in themselves.

The Chondrocranium.—tin Sphenodon the cartilaginous elements of the skull arise
before those of the greater part of the vertebral column, and the ossifications in
membrane before those in cartilage of both skull and vertebral column. ‘The first
differentiation to form the primordial cranium which we have observed is at Stage P,
and it consists mainly of pro-cartilage. It can be resolved into two perfectly distinct
portions, excluding the mandibular arch—an anterior common to the olfactory and the
trabecular regions, a posterior involving the sphenoccipital and auditory regions ?.
Dealing with these individually, the anterior portion is seen to embrace the trabecule
(Pl. III. figs. 1 & 2, ¢.) and an ethmoidal constituent, consisting of an extensive
basal plate with two pairs of outgrowths—an anterior or olfactory pair (x.e.) and a
posterior pair—to be hereafter termed the ethmosphenoidal plates (e.s.), The trabecule
(tr.), widely separated and enclosing a spacious pituitary foramen (py.’), are already
hyaline, and pass gradually into the lateral edges of the basal ethmoid. The

1 Gaupp, E.: Verhandlg. anat. Gesellsch. Sammlg. y. (Anat. Anz. Bd. iii., Suppl.) pp. 114, 120 (1891), also
ibid. Sammlg. xii. (Anat. Anz. Bd. xiv., Suppl.) pp. 157-163 (1898), and Ber. naturf. Gesellsch. Freiburg i. B.
Bd. x. pp. 302-316 (1898).

* Left uncoloured in our illustrations. Concerning the embryo which furnished the sections for figs. 1
to 3, Pl. III., it is regrettable that before investigating it we had handed it on to another, who, in
decapitating it for other use, had cut through the auditory region. We found, however, on examination
of slightly younger specimens, evidence sufficient for the extension of the differentiation into pro-cartilage

into the regions included in the dotted lines in the figs.

38 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

posterior portion, at this stage disposed at right angles to the anterior (its anterior
extremity being alone visible from above, as in fig. 2), is seen to similarly consist of a
basal or parachordal plate (par.) also bearing two pairs of outgrowths, viz. an anterior
(0.s.), to be hereafter termed the ofosphenoidal plate, and a posterior, the auditory
capsule (c.au.), ‘This posterior portion is hyaline only at the anterior and lateral
borders of the parachordal plate, the anterior chondrification extending into each of
the otosphenoidal tracts. The intracranial notochord, enclosed within the basal para-
chordal plate, terminates anteriorly in a minute freely-exposed apex (nc., fig. 2), and,
as already pointed out by Dendy for Stage N (99%. p. 75), it takes a sinuous course.

Dismissing for the present the sensory capsules, which at this stage are simple and
cup-shaped, it becomes necessary for comparison of later stages to deal fully with the
ethmo- and oto-sphenoidal plates. ‘The former (es.) are large and wing-like and bear
no outgrowths. The latter are complex and wholly distinct from the trabecule.
Each of these otosphenoidal plates is seen to be extending upwards and outwards,
backwards and inwards, and directly forwards. ‘Two apertures are enclosed by it—a
lower (f. ii.), which transmits the third cranial nerve, and an upper (f- ?v.), which
transmits the fourth !. The processes to which it is giving rise (indicative of differen-
tiation along definite lines) are five in number (03.1 to os.’, Pl. III. figs. 1, 2, 3).

Before passing on to a later stage, we wish to emphasize the simple rod-like
condition and non-extension into the cranial wall of the trabeculz, which, except for
their connection with the procartilaginous basal ethmoid, are disposed serially with
the mandibular arch (pg.mh.).

At Stage Q, despite the short advance in time upon P, remarkable progress is seen
to have been made in the formation more particularly of the cranium, nearly all the
definitive components of which are now recognizable. The trabecula have now fused
posteriorly with the parachordal—not by their ends as might be supposed, but by their
postero-internal borders,—and they appear to us now to give rise to the basipterygoid
outgrowths (ds.', Pl. III. fig. 6). An accompanying upward rotation of the parachordal
(associated with cranial flexure) has brought about a consequent approximation of
the otosphenoidal plates to the trabeculee, with an accompanying fusion involving the
first and fifth otosphenoidal processes. Of these, the latter, passing downwards,
unites with the outer trabecular border, and thereby shuts off (f7., fig. 4) a jugular
foramen ; the former, uniting with the inner trabecular border, encloses a passage (f-a.)
for the ophthalmic artery.

More significant than the foreging is the change in position undergone by the
second and third otosphenoidal processes. Originally directed upwards, under the
combined influence of rotation and growth, they are now directed forwards, and, by
union with the posterior border of the sphenethmoidal plate, they have come to
bridge longitudinally the membranous lateral cranial wall. As the result of this, two

' Gaupp (1898, Berichte, p. 8) describes these nerves in the Lacertilian as related to a common fenestra.

DEVELOPMENT OF THE SKELETON OF THE TUATARA., 39

further fenestrze arise in the same vertical plane in front of those already described.
Of these the upper or lateral cranial fenestra (f.n., Pl. III. figs. 4, 6, 7) is wholly
membranous, transmitting nothing, the lower (f. 77.) giving passage to the optic nerve.
It will further be noted that with the establishment of this union between the ethmo-
and otosphenoidal plates the parts most nearly related to the latter have become
expanded and carried up by growth of the basi-ethmoidal plate, together with which
they constitute a considerable cartilaginous interorbital septum.

The fourth otosphenoidal process, originally directed downwards (os.*, fig. 1), now
carried up, looks straight backwards (cf. figs. 5 & 8), but it has remained free.

On appreciation of these important processes, which have effected so marked a
change in the configuration of the parts, it is evident that growth must be most rapid
in the otic border of the otosphenoidal plate.

The chrondrocranium at this stage, viewed from beneath, reveals changes which,
though less dominant than those described above, are in themselves remarkable.
Massive indeed have the basis cranil and auditory capsules become, under the accelerated
growth associated with the straightening of the basi-cranial axis and the marked
lateral expansion of the post-pituitary floor (cf. figs. 6 & 7). The occipital region
has now become conspicuous, by the upgrowth on either side (¢.0., Pl. III. figs. 6 & 7)
of a considerable cartilaginous lobe lying free of the auditory capsule, between which
and it there lies the huge interspace for the 9th, 10th, and 11th cranial nerves (figs. 6
2 Ups Ue 18D Gide)

Anteriorly to the trabecule the basal ethmoidal plate (cf. fig. 6), vertically extended
as has been seen, has undergone a forward growth—as is proved by the fact that its
length is now as great as that of the trabecule themselves, and it has also undergone a
downward rotation, very marked as viewed from the side (PI. III. fig. 4).

The pituitary foramen at this stage (py.', Pl. III. figs. 6 & 7), compared with that
of Stage P, as represented in the accompanying figs. (cf. fig. 2), would seem to have
undergone considerable reduction with advancing growth, When, however, it is
remembered that the figure of Stage P (fig. 2) is magnified 13 times, that of Q
(figs. 6 & 7) but 8, it will be evident that under the growth-changes going on the
trabecular tracts which more directly bound the foramen have been well-nigh stationary,
and that such reduction of the foramen as has taken place would appear to be rather
due to the mode of union between the trabecule and parachordal cartilages than to
actual cartilaginous invasion.

Finally, as to the sense-capsules—now both chondrified. Wit. the olfactory capsule
complication has set in. Its capsular portion (nc.) has entered into a union with the
anterior border of the ethmosphenoidal plate, giving off dorsally a short swpranasal
process (nc.', fig. 4) connected with the plate by an ethmonasal bar (e.b.) lying within
the outer border of the olfactory nerve foramen. At its anterior extremity it gives off
a prenasal process (nc.', fig. 4), which embraces the anterior wall of the nasal sac.

40 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

Somewhat similarly related to the postero-external wall of the sac is a large
quadrangular cartilage, the eatranasal (ex.), and from this four processes arise. ‘The
two anterior of these (ev. 1 & 2) are united to the ethmoidal bar so as to enclose
a fenestra (n,f./). The two posterior are free, and the third (ea. 3), together with
the posterior half of the parent cartilage, disposed at a sharp angle to the external
half of this, contributes to the support of the anterior orbital wall, bounding
ventrally the ethmoidal foramen (f-¢.), which transmits the ophthalmic branch of
the fifth nerve '.

In addition to these complex nasal supports, there is present at this stage in
the nasal floor a sheet of procartilage which, in order to complete our terminology,
we name the subnasal. ‘This, to which we shall return, is wholly independent in
origin, and by analogy to the extranasal we suspect that this may also arise
independently.

The only remaining changes in the chondrocranium are mainly of the nature of
advancing completion of the parts now described. No new elements are added
after Stage Q, These perfecting processes, as they may aptly be termed, are most
conspicuous at Stages R and T, which may accordingly be dealt with independently.

Stage R.—A very striking feature of this, as compared with the earlier stages, is the
straightening out of the ethmosphenoidal region, which at Q was downwardly rotated
(cf. Pl. III. figs. 4 & 8). This straightening process affects most conspicuously the
median parts (internasal septum), which now appear as if withdrawn under cover
of the extranasal cartilage (e@., fig. 8).

Equally striking are changes involving the antorbital and otoccipital regions.
That taking place in the former is of the nature of extension most markedly dorsal-
wards of the interorbital septum (s.7.), by continuation of the process of elevation of
the basal ethmoid already alluded to (antea, p. 59). Under the combined influences
at work, growth has become more rapid with the ethmosphenoidal than with the
otosphenoidal plate; and ready proof of this lies in the now upward direction of
the third otosphenoidal process (os.”, fig. 1), which at Stage Q (os.°, fig. 4) was arched
and reached the highest point. Of the fenestrae described at Q (which in life are
closed by membrane, except where they transmit nerves) only one has undergone
change, viz. that transmitting the fourth cranial nerve (f. 4, fig. 8). This is now
complicated, having become continuous with the fenestre transmitting the third
cranial nerve, the jugular vein, and ophthalmic artery—all four being now closed
by one continuous membranous sheet. It is clear, on comparison with Stage Q,
that the cartilaginous bridges which originally separated these fenestre (7. e., the fifth
otosphenoidal cartilage and its near neighbours) have been absorbed.

As an accompaniment of these changes, the small cartilaginous bar bounding at

' Cf. Osawa, 98%, p. 504.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. Al

Stage Q the front of the foramen for the fourth nerve has become much elongated
and brought into line with the second otosphenoidal process, so as to give the
appearance of a continuous bar. That this is not the case, however, is proved by
the fact that the second otosphenoidal process in reality is now represented by the
insignificant tract (fig. 8, os.2) lying between the ventral extremity of the cranial fenestra
(f.n.) above and the dorsal extremity of the optic fenestra (f.") below. Its apparent
forward continuation at this stage is due to the appearance in the cartilaginous inter-
orbital septum of yet another fenestra (/7., Pl. III. fig. 8), which is of necessity median.
Like the lateral cranial fenestra (f.n.), it is wholly membranous, and it alone merits
the term interorbital fenestra.

Turning to the occipital region, the foramen magnum is now seen to be completely
surrounded in cartilage, as the result of union between the upper ends of the occipital
cartilaginous lobes and the posterior walls of the auditory capsules, resulting (¢f. Pl. ITT.
fig. 9, é.0.) in the enclosure of the afore-mentioned interspace transmitting the
cranial nerves ix. to xi, above, and its conversion into a foramen. With these changes
another, probably correlated with the afore-mentioned upheaval of the ethmosphenoidal
plates, is recognizable, viz. the appearance in the postero-dorsal cranial roof of a
spatulate cartilage (so.’, Pl. III. figs. 8 & 11), which in its general relationships recalls
that figured and described by Parker! in Lacerta and Zootoca as “ supra-occipital.”
This is seen to arise posteriorly from a massive tract of cartilage overlying the foramen
magnum, which appears to us more extensively derived by the overarching of the
auditory capsules than of the occipital lobes. When the chondrocranium is viewed
from the side, at this stage, this “ occipital” cartilage is seen to be arched, and to
follow, with the antero-dorsal border of the expanded ethmosphenoidal plate, the arc of
the circle described by the top of the head, which at the earlier stage was followed by
the third otosphenoidal process (os.*, Pl. III. fig. 5). In this respect, the two may be
said to have been correlatively modified in accommodation to the roofing-in of the brain,
now possible under the diminution in relative rapidity of the growth of the central
nervous system.

An interesting detail at this stage is the presence in the basi-occipital region of a
minute depression, involving the lower border of the foramen magnum. Conversely,
the ventro-lateral border is on either side rounded and convex, the whole giving to the
chondrocranium, especially when viewed from above (PI. III. fig. 11) or from beneath
(fig. 12), the appearance (as has been pointed out by Gaupp ? for the embryo lacertilian)
of being doubly condylar.

In the nasal region the extranasal cartilage (ea., Pl. II. fig. 8) has increased in
size, but it has undergone no conspicuous change, except for the elongation of the

’ Parker, W.K.: Phil. Trans, 1879, p. 595,
* Gaupp, A.: 1898, Berichte, p. 6.
VoL. xvi.—part I. No. 6.-—February, 1901. G

42 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

fourth of its processes (ex.'), which now lies in an interspace between the palatine and
maxilla (cf. fig. X., ev.")1. The subnasal sheet (sb.), now chondrified, wherefore it may
be termed the swhnasal cartilage, has entered into continuity by means of a delicate
cartilaginous bar with the prenasal process (nc.") of the primitive olfactory capsule,
and by a less considerable bar with the extranasal cartilage (e#., fig. 8). It extends
inwards, partly underlying the vomers, and effects (as indicated in fig. 12,s.b.) an
infolding of the outer lip of the posterior nares.

Stage T.—At this stage the characters of the definitive chondrocranium are all
present, and, owing to the increase in size, we found it unnecessary in dealing with it
to resort to microscopic sections and reconstruction. Fig. 10, Pl. IV., delineates from
the left side this chondrocranium, divested of all dermal elements except the para-
sphenoid (ps.), now co-ossified with the basisphenoid (4s.), The most conspicuous
changes to be observed are two, (i.) the backward extension of the fourth otosphen-
oidal process (os.4) and its fusion with the auditory capsule at the base of the supra-
occipital bridge, (i1.) the elongation of the ethmo-nasal region, which is a main factor
in the final realization of the adult proportions and shape of the skull. As the result
of the fusion above-named, the lateral chondrocranial wall is now in a condition of
uninterrupted continuity dorsally with the olfactory and auditory capsules, and the
passage transmitting the fifth cranial nerve now becomes a perforated fenestra. In
proportion, size, and shape, the fenestrae have undergone aconsiderableamount of change,
mainly associated with the cartilaginous extension of the interorbital septum (s.7.). By
the extension of the lateral cranial wall, the process of closing in of the roof has
advanced, but there is no change of importance as compared with the preceding stage.

The nasal capsule has become modified by the fenestration (7,f."') of the extranasal
cartilage.

The cartilage-bones (which appear at Stage R, but, owing to their then feeble
condition, are not represented in our accompanying figures of the models at that,
figs. 9 & 12, Pl. III.) are seen assuming shape at S (figs. 4, 5, 6, & 7), but at T they
are in the condition most favourable for description. They are 9in all—3 median and
3 paired—and with the exception of the basisphenoid all are otoccipital.

When the skull is examined from beneath (PI. IV. fig. 6) the basisphenoid (d.s.) and
basi-occipital (d.0.) are seen to arise within the anterior and posterior regions of the
post-pituitary floor. ‘The former extends laterally into the cartilaginous basipterygoid
processes (s'.)?, which at Stage T terminate externally in dilated extremities, for
articulation of the pterygoid bones; and it also extends forwardly into the trabecular

* This is presumably the “ processus maxillarius posterior” of Gaupp, which he aptly compares with the
“‘antorbital” or palatal bar of the Anura and Ranodon (1898, Berichte, p. 8).

* We have found traces in transyerse section at Stages R-S of the paired ossification asserted by Baur (Zool.

Anz. Bd. xii. p. 45) to hold good for the basisphenoid and stated by Parker to be present in the Lacertilia
(‘ Morphology of Skull,’ 1877, p. 216).

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 43

region, so as to enclose the pituitary foramen, now undergrown by the parasphenoid
(cf. transverse section, Pl. IV. fig. 3). The basi-occipital (.0.) arises from a single
ossific centre. The exoccipitals arise as ossifications of the occipital lobes of the chondro-
cranium, and by extension reach the posterior boundary of the exit for the ninth to the
eleventh cranial nerves. Osawa has recently described (98*. p. 494), with perfect
accuracy, the adult condition of the nerve-foramina which result from this, and concern-
ing the hypoglossal foramina he gives two as the number present. He also describes

Fig. 7. Fig. 8.

Fig. 10.

Figs. 7 to 10.—Sections through the occipital region of Sphenodon showing the hypoglossus nerve-foramina at
different stages of development, and the sustentacular ligaments of the medulla. 7 and 8. Lateral
longitudinal sections at Stage S, x 33. 9. Lateral longitudinal section at Stage Q, x67. 10. Transverse

section at Stage R, x 33.
b.0., basiocepital ; ¢.0., exoccipital ; U.s., sustentacular ligament ; /.s.’, its exoccipital support; md., medulla
oblongata ; nc., notochord; x. wiz., hypoglossal nerve-roots and foramina.

two nerve-roots. | Gaupp accords a third hypoglossal foramen to the embryo Lacertilian
(Berichte, p. 5). Interesting this, in consideration of modern discovery concerning
the truncal origin of the hypoglossal nerve-bearing region of the skull. Still more
interesting when we record the fact that, whereas in Sphenodon, at Stage S, three hypo-

glossal foramina are present, with corresponding nerve-roots (z. z77., text-figs. 7 and 8),
G 2

44 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

at Q (text-fig. 9) there are four foramina and five roots. It is certain that, during
ontogeny, two roots at least disappear, and further investigation is necessary to render
perfectly clear the detailed nature of those which remain’.

We may most fittingly refer here to a series of ligamentous supports which, so far as
we can ascertain, are new. We first detected them at Stage Q in the occipital region.
At S each is very conspicuous, and with its fellow of the opposite side is closely
applied to the under face of the medulla oblongata. It is strengthened at its bases by
ingrowths of the occipital cartilage (/.s.', text-figs. 7, 8, & 10), and in the floor of the
neural canal it enters into a loose fibrous connection with the dura mater (¢éf. fig. 10).
This remarkable structure is repeated segmentally throughout the trunk-region of the
vertebral column, and we propose to term it the sustentacular ligament.

The supra-occipital calls for no special comment.

The opisthotic (op., Pl. IV. fig. 9), which Siebenrock has proved *, to be an inde-
pendent element (the “ paroccipital ” of Owen), is at this stage remote from both the
prootic and exoccipital, and the ossific centre of the former is now beginning to
monopolize the feebly-developed cartilaginous parotic process (p.p.), which appeared
at Stage Q and is still short. The prootic (“‘ otosphenoid,” auct.) (pro., figs. 8 & 10)
is a simple bone, and its processus anterius inferior, so characteristic of the adult °, has
not yet appeared, nor has ossification yet encroached upon the processus anterius
superior, which, still hyaline, forms (cf. fig. 8, ¢.) not only at this, but at Stages R
and §, a formidable projection.

The Mandibular Arch.—This is first differentiated at Stage P, in the form of a
minutely procartilaginous mass having a body or quadrate portion (Pl. III. fig. 1, g.)
bearing three outgrowths: an antero-dorsal or pterygoid (p.g.'), a postero-dorsal—the
future epipterygoid (columella), epg.,—and an antero-ventral, much the stronger of the
three, the Meckelian bar (mk.).

The main body or quadrate mass, at this stage somewhat squarish, is disposed
parallel with the parachordal (pc.), and throughout the later stages, at which the
rotation of the latter and the straightening out of the basis cranii already referred to
are effected, it retains this relationship, 7. ¢., the absolutely distinctive characters of the
whole arch are present in procartilage. Chondrification is seen to be setting in
independently in its body and the Meckelian bar, and even at this early stage the
latter is connected with its fellow symphysially by a thin procartilaginous tract. At
Q advancing chondrification of the Meckel’s cartilage invades the symphysial tract,
and the whole cartilaginous lower jaw becomes for the time a single hyaline mass.
It remains such until Stage T, when the definitive symphysis begins to appear.

* Of. Peter on Ichthyophis (footnote, infra p. 70).
* Siebenrock, F.: 1893, p. 304, English Transl.
° Cf. Siebenrock, F.: Transl. cit. p. 307, & fig. 14, pl. 10. & Bruhl, ‘ Zootomie aller Thier Kl.’ pl. 149. fig. 5.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 45

With advancing development, the chondrifying centre of the quadrate cartilage
extends into the pterygoid and epipterygoid processes in common, and with this
replacement there comes about the afore-mentioned rotation, under which the epi-
pterygoid process, originally directed backwards and downwards, comes to be upwardly
directed, the pterygoid bar being displaced accordingly. On the assumption of this
rotation and its definitive position, the quadrate portion elongates and develops two
processes—a dorsal or otic process (fig. 4, g.'), and a lower process, which appears
correlatively with the segmentation off of Meckel’s cartilage. Anteriorly its pterygoid
portion turns suddenly outwards and expands (cf. espec. Pl. III. fig. 6, pg.'). Con-
tinuing to elongate, it comes at Stage R to overlie the pterygoid and the inner half
of the os transversum, tapering to a point. Gaupp describes this cartilage in the
Lacertilian as merely extending “in the direction of ” the transversum. He points
out (Berichte, p. 9) that did it continue forwards it would enter the maxillary region
and that of the processus maxillarius posterior (our fourth extranasal process) of the
nasal capsule, it would realize the condition occurring in Ranodon and the Anura.
With this we fully agree; but we regard the extension over the transversum as
indicative of the retention by Sphenodon of a more approximately batrachian condition
than that thus far known for the Lacertilia.

In Sphenodon the study of the nerves and all possible relationships leaves no doubt
that the epipterygoid process is the homologue of the processus ascendens of the
batrachian quadrate cartilage, as recognized by Gaupp. He, however, seems to us
somewhat in doubt’ as to the actual occurrence in the Lacertilian embryo of a

»

cartilaginous connection between the epipterygoid “Anlage” and the quadrate.
In Sphenodon, so far from there being any doubt on this matter, not only are the
epipterygoid and quadrate originally preformed in one continuous cartilaginous tract,
but, from Stage R onwards, the portion of this which, after the establishment of these
two bones, remains, begins to ossify by extension of the quadrate centre, to form the
characteristic antero-dorsal quadrate lobe (Pl. IV. fig. 11), the presence of which
accounts for the close relationship of the epipterygoid and the quadrate in the adult.
The difference with the reduction of the jugal arch and the liberation and freedom of
the quadrate associated in the Lacertilia is one in respect to which the gap between
these and the Rhynchocephalia is immensely greater than between them and the
Chelonia?, to say nothing of the Crocodilia and other reptiles possessed of a fixed

* Gaupp, E., especially in his paper in Anat. Anz, Bd. vi. 1891, p. 107, and Berichte cit. 1898, pp. 9-11.

2 We can only express astonishment, mixed with regret, at the gratuitous assumption by Osawa (98 °%
p. 102), in seeking to explain away the Giintherian dictum concerning the relationships of the quadrate to
the pterygoid, that the latter arises from two ossific centres, of which the hinder has in Sphenodon become
co-ossified with the quadrate. There is no trace of any such posterior pterygoid bone actual or potential.

46 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

quadrate. And in this connection it may be remarked that if the detailed configura-
tion of the cartilaginous upper jaw be a criterion of relationship, the fact that a near
approach to the condition occurring in Sphenodon is that of the Cecilian Ichthyophis
glutinosa as recently described by Winslow * is of great interest, when it is remembered
that these Apodal Batrachia, in the possession of dermal ossifications and other well-
known characters, are the most approximately Stegocephalian of all living forms ”.

The Hyoid and Columella awris—Our observations concerning the hyoid apart from
its connection with the auditory apparatus are few. At the earliest stage we have
examined (viz. P) it has already appeared in procartilage in the form it assumes in the
adult, except for slight differences in general proportion, as is better seen at Stage Q
(Pl. III. fig. 4). We have no evidence pointing to a compound origin of its basal
portion such as that described by Gaupp ? for the Amphibian, or of the complexity in
structure of the order described by Siebenrock + for the Chelonia.

It is only as concerning the vexed question of the relationship between the colu-
mella auris and the anterior cornu of the hyoid that we need proceed to details. The
nature of this in the adult has been so oft recapitulated that it will suffice to point
out once more that, apart from theories based on alternative interpretations of the
facts of adult anatomy and surmises necessary for their defence, the real question
developmentally at issue is whether or not the hyoid cornu and the extrastapedial are
secondarily united, and whether the object called by Huxley suprastapedial does or
does not arise independently.

Huxley, in describing the parts of the adult, regarded® the whole columellar
complex as hyoidean, and the extra- and suprastapedial processes as parts of its
expanded outer extremity. Peters, and all subsequent investigators °, on the contrary,
with the exception of Versluys, who has recently argued’ in favour of original con
tinuity, have assumed that the connection between the extrastapedial and the hyoid
cornu is secondary, while Peters more especially believed the suprastapedial to have
been originally distinct. As great. testimony to the extreme care with which Huxley
worked at this problem, there stands the fact that he drew attention (op. cit. p. 398) to
the presence, on the inner side of the foramen (f-h., text-fig. 11, which for brevity’s
sake we associate with his name), of a fibrous differentiation included between the
extra- and suprastapedial processes.

* Winslow, G. M.: Tuft’s Coll. Stud. vol. i. no. 5, 1898, pl. iii. fig. 24.

* Cf. Boulenger, G. A.: P. Z. 8, 1895, p. 402.

* Gaupp ,E.: Morph. Arbeiten, Jena, Bd. iii. 1894, p. 399.

* Siebenrock, F.: Ann. naturhist. Hofmus. Wien, Bd. xiii. 1898, p. 424.

° Huxley, T. H.: P.Z.8. 1869, p. 391.

° Peters, W.: Monatsber. Akad. Wiss. Berlin, 1870, p. 15, and ibid. 1874, p. 40. Cf. also Baur, G.: Biol.
Centralbl. Bd. vi. 1887, p. 655; Killian, G.: Jen. Zeitschr. Bd. xxiv. 1890, p. 649; Osawa, G.: 98°, p. 520.

7 Versluys, Jan.: Zool. Jahrb. Anat. Abth. Bd. xii. 1899, p. 167.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. AT

Gadow alone among recent investigators has carefully examined a series of indi-
viduals, and he records further details. Chief among these is the discovery! that the
Huxleyean foramen may be reduced to the size of a pin-hole or absent (op. cit. p. 467)
—facts which point to the conclusion that its condition is indicative of variation in
degree of extension of chondrification, especially when it is remembered that it
transmits nothing.

Huxley described the head of the suprastapedial process (p. 397) as connected
with the parotic cartilage of the skull. Gadow, on the other hand, records in one
example a ligamentous attachment to this; he remarks of another that “it does not
touch the cranium” (p. 468); and of a third he writes, the hyoid is continued
“along the anterior and lower margin of the extra-columellar cartilage, upwards to
the parotic corner, when it does not fuse with, although it directly touches, the
cranial cartilage.” Sufficient this to show that the suprastapedial is in its ultimate
attachment variable.

With these facts in mind, we were especially attentive to the extrastapedial region,
and concerning it the following:—Examined at Stage S, and onwards to those stages
in which the adult condition is assumed, lateral longitudinal sections through the
quadrate (PI. V. figs. 13 & 14) show that bone to be unossified dorsally. It is seen to
be overlain by the squamosal (sq.), and when successive sections are followed outwards
the extrastapedial process (¢.¢.) is seen in the inner series to pass (Pl. LV. fig. 13) into
the suprastapedial (s.st.). As the sections become external the suprastapedial is seen
to approach the head of the quadrate and eventually to fuse with it, as in fig. 14
(s.st.), which passes through the Huxleyean foramen. Sections more superficial, as
regarding the continuity of the parts, combine the appearance of these two figures.
Examination of the whole series and dissection alike reveals (cf. Pl. IV. figs. 7 & 9)
an absence of cartilaginous connection with the skull; and in the denial of this we are
in agreement with Gadow.

The foregoing observations would at first sight appear contradictory to Huxley’s.
Examination of his fig. 4, however, reveals an error, in the fact that he has indicated
as the exoccipital the parotic process of the opisthotic, as is proved by his delinea-
tion of its articular extremity. Allowing for this correction, his “ parotic cartilage”
can only represent the articular head of the quadrate; and, if so, his description
amounts to that of a union between the suprastapedial and the quadrate, such as we
have described and have observed not only at Stage S but at T. And, as a con-
sequence of this, it follows that cartilaginous continuity between the suprastapedial
and the skull does not exist, and that the quadratic union applies to the adult as well
as to the young. Resorting to the earlier stages, with a view of ascertaining whether
this union is or is not primary, we find in sections at Stage R that it does not

1 Gadow, H.: Phil. Trans, 179 B, 1889, p. 468.

48 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

exist (cf. Pl. V. fig. 12), the quadrate head (q'.) and suprastapedial process (s.st.)
being distinct though closely approximate. Passing to Stage Q (figs. 10 & 11), the
distance between the two is seen to be much greater, the nearest approximation
being that of fig. 11.

Turning now to the suprastapedial process, and the fibrous interval of Huxley. ‘The
former arises at Stage Q asa simple upgrowth, seen in section at fig. 10, Pl. V., s.st.
When Stage R is reached, this is seen to be still elongating (text-fig. 11, s.st.) and to
have given rise at the middle of its inner border to a recurrent process (s.s¢.'), which,
passing downwards and inwards, becomes apposed to the columella auris (st.), to
which it is tied by a series of fibres, which pass obliquely between the two. Between its
recurved lower extremity and the columella a non-hyaline tract is present (*, fig. 12)

Fig. 11. Drawing from a reconstructional model, showing the detailed characters of the columellar head of
Sphenodon and its derivative processes at Stage R, x 30. Fig. 12. Microscopic section through the same,
parallel to the columellar axis, x 75.

ec. extrastapedial; f.2., foramen of Huxley; /’., anterior cornu of hyoid ; /y., ligamentous fibres ;
q., upper end of quadrate ; s.st., suprastapedial ; s.st’., recurrent process of the same.

which we conclude is that described by Huxley. It remains only to add that as the
process is absent at Stage Q it is of secondary occurrence.

As to the continuity between the hyoid cornu and the outer head of the columella
(extrastapedial process), we have evidence that for the earliest stages of differentiation
(P especially), when all the parts concerned are in the procartilaginous state, it is
complete ; but a very interesting detail arises—viz., that in some of a series of thick
sections which we possess there can be observed (Pl. V. fig. 5,*) a very feeble
suggestion of jointing, so feeble that it would be likely to be overlooked by anyone
not familiar with the sections. This, however, cannot be regarded as evidence of
original discontinuity between the columella and the hyoid cornu! It is seen to be
but a passing phase, indicative of either a probable ancestral or an incipient “jointing”
such as takes place elsewhere along the cornu (**); and, as compared with a later

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 4g

differentiation occurring at the base of the extrastapedial (Pl. V. fig. 120), the
primary independence of which has never been suggested }, it is insignificant indeed.

Holding the foregoing facts proof sufficient that the columella, extra- and supra-
stapedial are but the products of specialization of the upper extremity of the hyoid
arch, with which they are at all. stages continuous, we have in conclusion to direct
attention to some puzzling procartilaginous tracts, of which we have been unable to
detect a counterpart at a later stage. They are of the nature of two pairs of rounded
masses (one of which is represented in PI. V. fig. 1,7) disposed serially between the
roof of the pharynx and the auditory capsule, ventrad of the fenestra ovalis region, and
we are unable to hazard a guess at their significance.

Concerning the chondrification of the columella and the related anterior cornu of
the hyoid, we find at Stage Q, when the procartilaginous tracts above described become
hyaline, that all traces of the “jointing” disappear. Examination of figs. 6 to 9
(Pl. V.) shows this conclusively, and also that the hyoid cornu (h.') passes continuously
into the extrastapedial (ec.), and through that into the columella (s¢.). The inner
head of the latter, seen at the procartilaginous stage (PI. V. figs. 3 & 4, st.) to merge
into the feebly differentiated mass (¢.aw.) giving rise to the auditory capsule, at the
period of chondrification is seen to be structurally continuous with that now hyaline,
and in section (Pl. V. fig. 6, st.) delimitable only by a close approximation of its
peripheral cells. Later, it becomes free, and attached to the rim of the fenestra ovalis
by membrane, in the customary fashion (cf. Pl. V. fig. 12, st.). Its rod-like portion
commences to ossify superficially, in the manner of the parts of the vertebral column
and the otoccipital bones.

The Trabecule.—One very conspicuous feature of the afore-described stages in the
development of the chondrocranium is the non-extension or incorporation of the
trabecule into the lateral cranial wall. As pointed out (anted, p. 38), these remain
passive during the development of this.

Examination of the adult chondrocranium of Sphenodon, apart from a knowledge
of its development, might well arouse the supposition that its fenestra are due to
absorption of an originally continuous wall, of the cartilaginous fish type. One of the
most certain and fascinating of our results is the discovery that the cartilaginous
cranial bars are all due to continuous-growth processes, that the correlated fenestree
are in no way due to absorption, and that the trabecule play no part in the formation
of the lateral cranial wall. From first to last these are simple rods, lost by union

1 Kingsley, the latest worker who has dared to deal with the subject of the general morphology of the
auditory ossicles (with which we are not concerned), expresses his conviction (Tufts Coll. Studies, No. 6, 1900,
pp. 215-216) that the Lacertilian hyoid and columella are originally continuous in the embryo. He claims
for the “ extra columella ” an independent origin, but since he uses the term in an unconventional sense and
his figure (which does not bear out his description) leaves us in doubt whether his ‘“ extra columella” may
not represent the supra-stapedial process, we feel justified in the above statement.

vou. xvi.—Ppart 1. No. 7.—February, 1901. H

50 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

anteriorly with the basal ethmoid, united by their postero-internal extremities with
the parachordal; and, what is more, they are serially disposed at all stages with the
visceral skeletal arches.

Recent investigation by the reconstruction method has led to the conclusion that
the developmental processes occurring in the skull. of Man himself are not easily
reconcilable with those generally believed to be passed through by even that of certain
other mammals !.

As is well known, Salensky in 1878 described? in the embryo Sturgeon a distinct
cartilaginous centre for the lateral cranial wall; and Stohr, in 1880, discovering that
the parachordal of Triton? appears in two pieces, in 1882 showed* the basal portion of
the chondrocranium of Rana to be complex, if not actually composed of three pairs
of distinct elements—trabecule, “‘mesotic cartilages,” and “ occipital plates” (para-
chordals). Miss Platt has later described in Necturus® the dorsal part of the “ crista
trabecule” as paired, and instituted, on consultation with Sewertzoff, a comparison
with the alisphenoidal cartilage originally described by him in Acanthias in 97%.
While Peter, in the same year as Miss Platt, recorded the formation in Ichthyophis* of
so-called “dorsal trabecule.”’ Most important of all, however, is the full monograph
of Sewertzoff, which has appeared during the progress of our work, in which *, bringing
the whole subject to a focus, he shows that in the Klasmobranch Acanthias the trabecule
take an insignificant share in the formation of the lateral cranial wall, and that this is
mainly formed on either side from the above-mentioned distinct cartilages (termed by
him the alisphenoidal), the pair of which, uniting with the trabecule, contribute what
he has termed the prochordal portion of the resulting chondrocranium. In his
memoir he meets the challenge that if this cartilage be of the importance he claims, it
should be more generally forthcoming, by showing reason for its being present in
Pristiurus, that W. K. Parker had seen it in the Salmon®, and that other
observers, and more particularly Miss Platt and Peter referred to above, had probably
done so in other chordate forms. In view of this and of the similarity in posterior
extension of the trabecule along the parachordal in Acanthias and Sphenodon, and of
the relationships of the latter to our otosphenoidal plate (PI. II. fig. 1), we consider
that this may perhaps represent Sewertzoff’s alisphenoidal cartilage 1°.

1 Levi, G.: Archiy mikr. Anat. Bd, lv. 1900, p. 407.

Salensky, W.: Zool. Anz. Bd. i. 1878, p. 289.

* Stohr, Ph.: Zeitschr. wiss. Zool. Bd. xxxiii. 1880, p. 477.
Stohr, Ph.: Ibid. Bd, xxxvi. 1882, p. 91.

> Platt, Miss Julia: Morph. Jahrb. Bd. xxv. 1897, p. 377.

* Sewertzoff, A.: Anat. Anz. Bd. xiii. 1897, p. 413.

Peter, K.: Morph. Jahrb. Bd. xxv. 1898, p. 555.

Sewertzoff, A.: Kiipffer Festschrift, Jena, 1899, p. 281.
* Parker, W. K.: Phil. Trans. 1883, p. 129, pl. v.

* During the passage of this Memoir through the press, Sewertzoff has announced details concerning the

development of the skull in the Gecko (Ascahabotes fascicularis) which fully supports this conclusion (cf. Anat.
Anz, Bot. xviii. p. 36, 1900).

o

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 51

Far reaching as is his discovery, and interesting as are its bearings on our own
work, we venture to think that the most rational interpretation to be put upon the
behaviour of the trabecule in Sphencdon is that of Huxley, originally put forward in
his Hunterian Lectures in 1864, that they represent a pair of pra-oral visceral arches.
Huxley reiterated this conclusion in 1874, in his suggestive note on Amphioxus }, and
von Kiipffer gave it consideration and support in 1893 2, in his discovery of a pair of
pre-oral visceral diverticula in the embryo Sturgeon. Further consideration of this
very important topic is beyond the possibility of this memoir, but we hail with delight
the discovery, as our work was nearing its termination, by von Davidoff, of the
existence of this very pair of diverticula in the Lizards Platydactylus and Lacerta.

Cranio-facial Membrane-Bones.

The anatomy of these has been so fully dealt with by various authors, and most
recently by Osawa (98*. p. 497), that we have little to add to their descriptions.
Developmentally, however, some interesting considerations arise. At Stage Q, the
earliest at which we have been able to observe membrane-bones, the vomers, palatines,
pterygoids, maxille, postorbitals, squamosals, angularia, supra-angularia, and dentaries
are all present (PI. III. fig. 5) and remote from each other. By the time that R is
reached, all the membrane-bones present in the adult are represented (¢f. PI. III.
figs. 10-12). Looking at the skull from the side, this does not at first sight appear
so, but when examined fully it is found that while the frontals are approximated in
the middle line, the parietals are widely divaricated and small and of a remarkable
angulated type. Examination of the skull at this stage shows that the frontal and
posttrontal, the prefrontal, maxilla, jugal, and postorbital are all in close relation-
ship, first active development having apparently involved those elements which are
circumorbital—a fact which immediately impresses itself on the mind when, at this
stage, the skull is viewed either from above (fig. 11) or the side (fig. 10). And one is
led to speculate how far this may not be indicative of a first protection of the eye,
when it is remembered that the paleontological record proves the circumorbital

1 Huxley, T. H.: Proc. Royal Soc. vol. xxiii. 1874, p. 131.

There is evidence among Huxley’s unpublished notes that in the early 80’s he was returning to this conception
and to work upon the skull. He was bringing to bear upon it the discovery in the Elasmobranchs of a fourth
branch of the trigeminal nerve, to haye been termed the palato-nasal or hyporhinal. This term was intended
to express the fact that, in relation to the trabecul, this branch of the fifth cranial nerve, together with the
ophthalmic (for which he had already introduced the correlative term orbito-nasal, in his article ‘* Amphibia,”
Encyclop. Brit., Vol. i. Edit. 9, p. 767), repeats the condition of the other cranial nerves in relation to their
visceral arches and clefts, and thereby presupposes the existence of a pre-oral cleft. And, further, he was
building up an argument on this basis to show that in these facts there lies the explanation of the mode
and point of termination anteriorly of the notochord.—G. B. H.

» Kiipffer, C. von: Stud. d. vergl. Entwick. Kopfes d. Kranioten, Hit. i. detpenser: Miinchen, 1893, p. 89.

H 2

52 PROF. G. B. HOWES AND MR, H. H. SWINNERTON ON THE

=

region to have been the first seat in order of time of the development of dermal
plates |.

Passing to the palate, it is seen that at this stage approximation is most marked in
front, for while the vomers have met in the middle line, the pterygoids are widely
divaricated behind. A noticeable feature is the fact that the palatines, which support
the orbital floor, have apparently shared in the afore-mentioned rapidity of growth.
From this stage onwards, the salient feature in progressive development is the closing
in towards the middle line of the bones of both the cranial roof and palate, rendered
possible by the fact that the most rapid phases in the growth of the brain have now
passed. Comparison of Pl. III. figs. 11 & 12, and Pl. IV. figs. 5, 6, and 8, will
render clear the changes undergone in the individual bones during the process, which
it is not necessary to describe in words.

It is at the stage (R) that the parasphenoid first appears, in the form (PI. III.
fiz. 12, p.s.; im section in Pl. IV. fig. 1) of a minute bony element which would most
certainly be lost to sight in ordinary dissection, lying freely beneath the antero-median
border of the post-pituitary plate. With advancing development it assumes an arrow-
head shape and a more intimate relationship with the basis cranii, fusing by its broad
posterior extremity at Stage S with the basisphenoids, and closing the pituitary foramen
as it does so by extension anteriorly (Pl. IV. fig. 3).

We have already drawn attention (anted, p. 2) to the interest attaching to this bone.
It was overlooked by Giinther, Briihl, and others, and its discovery was first claimed
by Fritsch, who believed he had observed it as an independent element’. Baur
immediately challenged the alleged independence 3, and gave an accurate account of
its limitations in a young individual. Fritsch compared the supposed parasphenoid
with that of Hyloplesion, and comparison of his figure of this with that given by
Credner (op. cit. p. 513) of the presumed co-ossified basi- and presphenoids of
Paleohatteria at once arouses suspicion by the close similarity in shape of the two;
while further complication arises from the fact that Baur, commenting on Credner’s
discovery, regards* his basi-presphenoid as a parasphenoid alone. Fritsch for
Sphenodon, and Credner for Paleohatteria, were dealing with the compound basi- and
parasphenoid, and were therefore in error. Baur was right only in his delimitation
of the parasphenoid of Sphenodon.

The pterygoids, as already remarked, are developed widely apart, apposition in the
middle line commencing anteriorly at Stage R, at which (Pl. III. fig. 12, pg.) they
already reach the vomers—7. é., their forward extension is thus recognizable as soon as

Of. Newberry, J. S.: Monogr. U.S. Geol. Survey, vol. xvi. 1889, p, 108, pl. xliv.; and Jeeckel, O.: Sitzb.
Ges. naturf. Fr. 1892, p. 90. .

* Fritsch, A.: Fauna d. Gaskihle d. Permform. d. Bohmen, Bd. ii. 1889, p. 58.

* Baur, G.: Zoolog. Anzeiger, Bd. xii. 1889, p. 45.

* Baur, G.: Amer. Journ. Sci. 1889, p. 311.

DEVELOPMENT OF THE SKELETON OF THE TUATARA, 03

the bones assume a mutual relationship, and is not brought about by ontogenetic
growth. At Stage R (PI. III. fig. 12) it will be observed that the anterior edge of the
palatine (pa.) is transverse and that the vomers (vo.) lie wholly in front of them;
whereas at Stage S (PI. IV. fig. 6) the palatine border is angulated and the vomers are
correspondingly modified. Proof that this change has arisen by backward elongation of
the vomers, lies in the study of the relationships to the posterior nares, and it therefore
follows that in the all-characteristic vomero-pterygoid apposition the vomer has played
apart. Boulenger, one of the advocates of the Rhynchocephalian affinities of the
Chelonia, has called special attention! to a similar apposition in this order; but con-
cerning it the process is the reverse of that of the adult Rhynchocephalian, it being
the vomer which for the most part reaches back to the pterygoid. Judged by the
foregoing ontogenetic changes undergone by the developing Sphenodon, this feature,
instead of presenting, as might appear, a difficulty in the way of the acceptation of the
said affinity, strengthens it, since both bones are in both groups of animals involved
in the apposition, though in an inverse degree.

In Ichthyosaurus the vomers extend back divaricatingly behind the nares, and the
pterygoids, inserting themselves between them, extend forwards between the nares 2.
Taking the Stage R of Sphenodon as the starting point, the Ichthyosaur might well
represent one extreme of modification, the Chelonian, through the adult Sphenodon,
an opposite one; and in consideration of accepted views of the Chelonian affinities of
the Plesiosauria ®, it is interesting indeed to find that in these they are the vomers
which longitudinally extend *.

The interest in the pterygoid of Sphenodon does not stop here, for, on examining its
basicranial articulation we have found a synovial joint to be present and an indepen-
dent interarticular cartilage (Pl. 4, figs. 1 & 3, m.p.), which flanks the inner face of the
pterygoid and has an essential similarity to the meniscus mandibuli. We therefore
propose to term it the meniscus pterygotdeus °.

Cognate to the study of the pterygoid is the presence of a process of the squamosal
hitherto unrecognized, which (PI. IV. fig. 11, sq.') extends downwards and forwards
between the quadrate and pterygoid, and, together with a process arising from the
posterior border of the squamosal (sg.", Pl. IV. fig. 9 and Pl. V. fig. 18), embraces the
expanded otic head of the quadrate. Both are present in the adult, the hinder process

being the less conspicuous of the two.

? Boulenger, G. A.: Brit. Mus. Catal. edt. p. 17.

* Cf. Baur, G.: Anat. Anz. Bd. x. 1895, p. 458, fig. 1.

* Of. Andrews, C. W.: Quart. Journ. Geol. Soc. vol. lii. 1896, p. 251, fig. 2.

* Cf. Andrews, C. W.: Geol. Mag. (iv.) vol. ili. 1896, p. 4, and Ann. & Mag. Nat. Hist. (6) vol. xv. 1896,
p. 345.

° Parker has undoubtedly seen and figured this in Zootoca (Phil. Trans. 1879, p. 612, & pl. 45. fig. 4), but
his descriptive paragraph (§ 7) can hardly be said to adequately describe it.

54 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

The “ Squamosal.”—This bone has been most fully described by Baur, who? has
accurately dealt with its relationships to the parietal, postorbital, jugal, quadrato-jugal,
quadrate, and paroccipital process. It is unnecessary here to recapitulate the details
of this association, which our figures render sufficiently clear, except to remark that
we have extended the relationship to the pterygoid.

In the progress of investigation into the comparative osteology of the fossil reptiles,
the varying conditions of the squamosal and supratemporal, one or both of which may
be present, have become the subject of much consideration. The presence of the two
has been regarded as a lowly characteristic, if only by way of analogy to the Stego-
cephalia. Cope and Baur are conspicuous among those who have utilized these bones
in the determination and discussion of affinity, and nothing short of a deplorable
confusion has arisen from their inconsistency in the usage of terms °, and the fact that
while one of them arrived at an inversion of the order adopted by certain contemporary
writers, he finally complicated matters* by needlessly reviving for the reptilian
squamosal Owen's term ‘‘ prosquamosal.” A final agreement was never arrived at, and
the question therefore arises as to which of the two bones is for the future to be
regarded as the supra-temporal.

As a general rule these bones lie side by side in the same transverse plane. The
term supra-temporal was applied by Bakker to the inner one‘, in dealing with the fish
skull. Cuvier denoted the presumably homologous bone in reptiles the ‘“‘mastoid”®; and
Owen, retaining this term, applied © to the outer of the two (Cuvier’s “ temporal’’) the
term squamosal. ‘To be consistent, therefore, on the assumption that the inner of the
two bones, having similar relationships in fishes and reptiles, is homologous,
convenience and precision are met by terming the inner the supra-temporal, the outer
the squamosal. And it is in this sense that we use these words’.

Our knowledge of the paleontological history of the Rhynchocephalia has during
recent years been materially advanced by the description by Lortet of remains from
the Jurassic of France. In his memoir already cited (antea, p. 3) he drew attention
in Saphzosaurus (Sauranodon) to a ‘“ parieto-squamosal” complex, in respect to which

* Baur, G.: Anat. Anz. Bd. x. 1895, p. 321.

* Cf. Baur, G.: Anat. Anz. Bd. i. 1886, p. 349, and Bd. ii. 1887, p. 657! and, as an awful example, the
series of notes embodying the dispute between him and Cope in Amer, Nat. vols. xxix. & xxx,

° Baur, G.: Anat. Anz. Bd. x. 1895, p. 320.

* In Cuvier and Valenciennes, Hist. Nat. des Poissons, t. i. 1828, p. 338.

° Cuvier, F.; Ossemens Fossiles, t. x. 1836, p. 14.

° Owen, R.: Catal. Osteolog. Series R. Coll. Surgeons, vol. i. 1853 (table), p. xxxviil.

7 Concerning the afore-mentioned confusion, Fraas for example, in his revisionary memoirs on the Ichthyo-
sauria and Stegocephalia, following in respect to the latter the lead of Huxley, Miall, Fritsch, and Credner,
refers to the inner bone as the squamosal, the outer as the supra-temporal. Zittel adopts the Huxleyean
order for the Reptilia and Stegocephalia, with confusion arising out of the interpretation of the latter in the
Lacertilia as the quadrato-jugal. Briihl is still more glaringly inconsistent and contradictory ; while even

DEVELOPMENT OF THE SKELETON OF THE TUATARA, 55

Boulenger first showed him! to be probably in error. Baur, accepting Boulenger’s
correction, has sought to show? that the bones regarded by him as the supra-temporal
and squamosal lie within the area of the ‘“‘ squamosal”’ of Sphenodon, and that that
bone is therefore compound. Shuffling the terms, he regarded the body of the latter
with its laterally visible processes as a “ prosquamosal ” (‘‘squamosal ” awct.) and its
posterior ascending process as the squamosal (“‘ supra-temporal ” auct.).

Seeking for evidence in support of this in the Tuatara, Baur admits that none was
forthcoming in a skull of 25 mm, in length (op. cit. p. 321). Not only have we failed
in all attempts to detect any such separation, but also to observe at any period traces
of a second element. While we fully admit that this so-called “ squamosal” of
Sphenodon combines the structural relationships of the supra-temporal and squamosal
as originally defined, failing the discovery of any trace of its supposed double nature,
we are disposed, on consideration of the behaviour and all detailed relationships of the
supra-temporal in the Lacertilia, to regard it as a squamosal, and to interpret its
ascending limb, which meets the parotic process of the parietal, as secondarily acquired.
The alternative would be the introduction of a new term, in which neither
““squamosal’’ nor ‘‘ temporal” were compounded, but we have no wish to render
confusion more confounded. ‘The future can only settle the question, and we are
content to leave it to that.

The Quadrato-jugal.—this bone, as is well known, was first recognized in Sphenodon
by Dollo%, and later more fully described by Baur*. We have nothing to add to their
descriptive account of it. Its most characteristic feature is its enclosure with
the quadrate (qu. & q,j., Pl. IV. figs. 7 & 9) of a conspicuous foramen. Osawa, the
latest writer upon it, terms it (98*. pp. 499 & 520) the “tympanic,” presumably
on account of his inability to regard the mammalian tympanic as the homologue of the
quadrate; and associated with the study of this bone there is a matter of no little
importance, if, as we believe, the tendency of our time is in error.

Baur, in 1889, argued® against the generally accepted belief that the single

Smith Woodward is not uniform in his terminology. Boulenger, onthe other hand, is so, and, like ourselves,
he retains the terms for the bones to which they were originally applied—z. e. for him, in both fishes and
reptiles, the inner is the supra-temporal, the outer the squamosal. Difficulty admittedly arises when but one
bone is present, and there is no doubt that in many such cases the problem can only be solved develop-
mentally ; but, on comparison of those lizards in which both bones are present, we believe him to be right in
regarding the bone which alone suspends the quadrate in the Ophidia (Brit. Mus. Cat. ‘‘ Ophidia”) as the
supra-temporal, and not the squamosal as do Huxley and his followers.

* Boulenger, G. A.: Ann. & Mag. Nat. Hist. (ser. 6) vol. xi. 1893, p. 209.

* Baur, G.: Anat. Anz. Bd. x. 1895, p. 322, cf. also Amer. Nat. vol. xxx, 1896, p. 145.

* Dollo, L.: Bull. Mus. R. Nat. Hist. Belg. t. ii. 1883, p. 235.

* Baur, G.: Zool. Anz. Bd. ix. 1886, p. 685.

° Baur, G.: Journ. of Morphol. vol. iii. 1889, p. 473.

56 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

temporal arch of the Squamata represents only the upper arch of the Rhynchocephalia,
basing his conclusions on the surmise that the quadrato-jugal is not unrepresented in
the former as is usually supposed, but that the bone generally termed the “squamosal”
is its homologue. Somewhat similar conclusions follow from the later determinations
of Gaupp, laborious but unconyincing, in which he seeks to show! that the bone
hitherto known as the quadrato-jugal in Batrachia and Birds must be for the future
termed the ‘“quadrato-maxillary,” and that for the quadrato-jugal in Crocodilia,
Chelonia, Rhynchocephalia, and Lacertilia, the term “ paraquadrate” must be
employed.

Baur assumes that the Squamata ‘“‘ never possessed an infra-temporal fossa, but that
the broad arch was reduced from below in the same way as in the Testudinata ” (op. cit.
p. 473). It is beyond the scope of this memoir to fully discuss this question,
voluminous in itself, but there tells strongly against the interpretation of the bone
which in the ‘‘Squamata” reaches the head of the quadrate with that which in the
Rhynchocephalia flanks its lower articular border, the fact, long ago pointed out by
Huxley ”, that in the living Lacertilia there is present a ligament having the relation-
ships of the latter. And, further, argument by analogy to the living Urodela, in
which, while the maxillo-jugal arch is complete in bone only in the Hastern genus
Tylototriton *, a similar representation is present in ligament which may extend even
into the maxillary region, places a further obstacle in the way of its acceptation. All
recent investigation has gone to show that the Reptilia and the Batrachia are the
diversely modified descendants of the Stegocephalia; and the fact that in them the
supra-temporal, squamosal, and quadrato-jugal coexist in a transverse series tells with
great force against this seductive argument.

The “ Septo-maaillary.”—This bone was originally described in Sphenodon by Osawa
(98*. p. 503) as a small semicircular element attached by fibrous tissue to the vomer,
and he therefore named it a “turbinal.” In this he was unquestionably in error. The
bone was figured and described by Parker in Zootoca+ as the septo-maxillary, and
under this name it has been more recently described by Gaupp in other lacertilian
embryos. Concerning its detailed relationship, he associates 1t with the support of the
septum nasi internally and with that of the border of the cartilage enclosing Jacobson’s
organ superficially (op. cit. Ber. p. 10). The bone present in Sphenodon (PI. IV. fig. 2,
sma.) is still more superficial in position and free of the nasal septum than this. In
consideration of the fact that whereas here the Jacobson’s organ is completely roofed in
cartilage, in the lizard, according to Parker, the septo-maxillary fulfils that function °,

* Gaupp, G.: Morphol. Arbeiten, Jena, Bd. iv. 1895, p. 77.
* Huxley, T. H.: Anat. of Vertebr. 1871, p. 190.

* Riese, H.: Zoolog. Jahrb., Anat. Abth. Bd. y. 1892, p. 99.
* Parker, W. K.: Phil. Trans. 1879, pt. ii. p. 609.

* Parker, W. K.: Phil. Trans. 1879, pl. 44. fig. 5.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 57

we are disposed to regard the bone as its homologue. It is figured in the macerated
state at Pl. VI. fig. 1, s.me., and, as remarked by Gaupp, is a membrane-bone.

The supposed “lachrymal” of Giinther (67. p. 597), accepted by Hofmann},
Seeley (?) 2, and Credner 3, has no existence.

The Pre- and Postfrontal and Postorbital.—The two former are proved by their
development to be membrane-bones*‘, and examination of Pl. IV. fig. 10 shows that
they are neither of them compound and that there are no correlated chondro-cranial

ossifications.
The postorbital has the customay relationships of that bone and is very large 5.

1 Hofmann, C. K.: Bronn’s Klass. u. Ordng. d. Thier- Reichs, Bd. vi. Abth. 3, pl. 66. fig. 5.

* Seeley, H. G.: Journ. Linn. Soc., Zool. vol. xii. 1876, p- 184. ‘In front is a small lachrymal, which is
not found in Chelonians.” The context is not clear.

* Credner, H.: op. cit. p.510. Baur has pointed out the error here, Amer. Journ. Sci. vol. xxxvii. 1889,
p. 311.

* We retain the term prefrontal, as one now in general use. It is, however, unfortunate (since it was
originally applied by St.-Hilaire, in 1807, to a cartilage-bone, which Cuvier in his ‘ Lecons’ defined as trans-
mitting the olfactory nerve) that it should have become applied indifferently to various cartilage and membrane
bones occurring in the prefrontal region. A great confusion exists with respect to the modern usage of the
term, but it does not materially affect our work.

° The study of the postorbital in‘Sphenodon is intimately bound up with Giinther’s work upon the living
Crocodilia, which possess but a single so-called “ postfrontal.” On the basis of comparison with this he came
to regard the postorbital of Sphenodon (which, following Stannius, he termed “ quadrato-jugal”) as “a
detached portion of the postfrontal” (67. p. 598). Baur discovered in 1886 (Zool. Anz. Bd. ix. p. 740)
that both postfrontal and postorbital are present in Belodon, and accepted Giinther’s conclusion concerning
Sphenodon. Their reasoning suggests an origin of the postorbital from the postfrontal, rather than that both
bones were originally distinct, and that the presence of one or both is due to variation by co-ossification with
age. And, as bearing upon this, we submit the following observation :—Cuvier showed that in the Iguana
(‘Lecons, t. x. p. 14) there are two bones occupying the region of the postfrontal of other Lizards. He
applied to both this term, and figured them as attached side by side to the postorbital process of the frontal.
In our own example the hinder bone alone has this relationship, the former being pushed forwards in front of
the process named. Comparison with the single “postfrontal” bone present in many Lizards—e.y., the
familiar backwardly-pointed bone of Varanus—shows this to have the detailed relationships of Cuvier’s two
“ postfrontals” in Iguana, wherefore suspicion arises that it is perhaps compound, That this may be the
case is proved by the skull of a young Tupinambis in our possession, in which, as Mr. M. F, Woodward has
shown us, two bones are present in its place. Contrary to what happens in Iguana, the postfrontal is alone
attached to the frontal and the postorbital to it. This notwithstanding, it follows that the bones described by
Cuvier in Iguana are the postfrontal and postorbital, and that they are both represented in tke varanoid type
(cf. also Gaupp on the embryo Lacerta, in Morph. Arbeiten, Bd. iv. p. 77, pl. vi. fig. 9), We are also
indebted to Mr. Woodward for drawing our attention to a skull of the Green Turtle (Chelone mydas) in our
Teaching Collection, in which that portion of the ‘“ postorbital” suturally connected with the anterior two-
thirds of the frontal is on the left side distinct—7. ¢., an independent postfrontal is present.

These facts go far to prove that in the Reptilia generally, where either a single “ postfrontal” or “ post-
orbital” is alone present, it may be a compound of these two; and they certainly suggest that the postfrontal
of the living Crocodilia may have gone elsewhere than over to the frontal, as surmised by Baur.

VOL. XVI.—PART I. No. 8.—February, 1901. I

58 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

The Mandible.—The mandibular ramus has been shown by Baur to consist (95*.
p. 413) of the six elements usually present in that of other Reptilia. He originally
described it in 18911 as resembling most closely that of those Chelonia in which the
angular and supra-angular, apposed behind the splenial, under-arch the articular, and
as destitute of the 7th element or ‘“ presplenial” descrihed by him in these animals.
We have only to add that at the latest stage observed by us (T) the articular has not
yet appeared, the articular region being still cartilaginous, and that at Stage S the
angular and supra-angular (s.¢., Pl. IV. fig. 4) are still separated by the splenial (sp.).

6. THE APPENDICULAR SKELETON.

The Pectoral Girdle-—Concerning this we have little to record. ‘The simplicity of
the coracoid was pointed out by Giinther, in the remark (67. p. 611) that it has
“no notch whatever.” Fiirbringer, in a passing allusion seven years later ?, commented
on the rounded border and feebly ossified state of this (Pl. VI. fig. 6, cor.), and there
can be no doubt that in respect to these features it simplifies the Lacertilian type. As
pointed out by Fiirbringer, however, the Chameleons approximate to a similar con-
dition, but it may be questioned whether the “ simplification” in them is not due to
secondary causes. Ossification takes place during Stages S and T, on lines common to
both the Batrachia and Reptilia. An interesting detail is the early appearance of the
clavicle, viz. at Stage Q (Pl. VI. fig. 4, cl.), at which no cartilage-bones are anywhere
present in the axial skeleton. The interclavicle appears later. We have failed in all
attempts to find evidence of a cartilaginous predecessor of these bones.

The relationships to the sternum we have already described (antea, p. 33).

The Pelvic Girdle.—Giinther accurately described the adult girdle, except that he
applies to the ileo-pectineal process the term ‘“‘uncinate” (67. p. 615). Like the
shoulder-girdle, it is at Stage Q fully chondrified. Its two halves (Pl. VI. fig. 7) are
united, and there is a considerable cartilaginous symphysis (¢.¢.p.) which in the mid-
ventral line separates the cordiform fenestre (f.c.). With later growth (at Stage R)
a backwardly-directed median process (the hypoischium of Mehnert*) becomes con-
spicuous, but it is never segmented off or ossified to form an ‘os cloace” as in
Lacerta. The epipubic cartilage (e.) like it is simple—i. ¢., there is nothing to
suggest those processes of bifurcation and subdivision recorded for certain Lacertilia.

Interest attaches to the ligamentum medianum pelvis, from the fact that while
Wiedersheim has described in its place in the adult a cartilaginous tract uninter-

" In his 1895 notes he admits a transposition in those of 1891 of the terms angular and splenial, but it
does not affect his comparison. :

* Fiirbringer, M.: Morph. Jahrb. Bd. i. 1876, p. 643.

* Mehnert, E.: Morph. Jahrb. Bd. xvii. 1891, p. 123.

' Wiedersheim, R.: Zeitschr. wiss. Zool. Bd. liii. 1892, p. 54.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 59

ruptedly continuous with the epipubis and hypoischium, Mehnert has denied (op. cit.
p. 142) a “skeleto-vicarious ” significance to this ligament for Lacerta. Our develop-
mental material shows that Wiedersheim was in error, since the ligament is already
present (Pl. VI. fig. 8, Zz.) at Stage R. Concerning Mehnert’s conclusion, we can
only add that in Sphenodon the ligament is preformed in cartilage (Pl. VI. fig. 7, c.i.p.)
at first of considerable extent, and that with advancing development, correlatively with
the expansion of the pelvis and widening of the cordiform fenestre, this undergoes
a relative reduction with accompanying replacement in fibrous tissue. If Mehnert is
correct, the cartilaginous symphysis and the primarily small size of the fenestre carry
Sphenodon so much nearer the Batrachia.

In the course of our work our attention became arrested by the fact that there are
apparently two types of hip-girdle represented in the adult. We append camera-lucida
figures of these. When viewed from beneath, it is evident that the essential difference

Fig. 13. Fig. 14,

Camera-lucida outline sketches of extreme types of the adult pelvis of Sphenodon.
13, least expanded ; 14, most expanded. Nat. size.

between them is one of increased length as compared with breadth. In the pelvis of
the least expanded type (text-fig. 13) the cordiform fenestra are more rounded than in
the most expanded, in which they appear (fig. 14) angular; and we find that whereas
in the least expanded type the transverse measurement across a-) is about equal
to that along c-d (fig. 13), in the most expanded (fig. 14) c-d is greater. We note,
however, that in all cases the distance between the opposite limits of the cordiform
fenestre is equal to that of the symphysis ischii from the vertebral column and’to the
transverse diameter of the sacrum.

For want of material undoubtedly mature upon which to base further comparison,
we are unable to decide how far this is or is not a sexual matter; but we are disposed
to believe the contrary. ‘The only other case known to us, which is at all analogous,
is that of the presence of two still more distinct types of scapule in an extensive
collection of bones of the Australian Dugong brought home by Professor Haddon.
F.R.S., from Torres Straits in 1889, now in the custody of one of us.

12

60 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

The Long Bones.—Under this head we include the humerus and femur, radius and
tibia, ulna and fibula. They have all been so often described, from Giinther to
Osawa, that detailed recognition by us would be superfluous. We would only add that
the condylar foramina of the humerus, originally observed by Dollo (84), are both
fully formed at Stage Q (PI. VI. fig. 10, fien., fec.), and that the inner has from the
first period of differentiation its canal-like character.

The long bones are the first of all the cartilage-bones to ossify.

Carpus and Tarsus, with Phalanges.

It is evident, from the study of both carpus and tarsus, that chondrification sets in
correspondingly (for the tarsus, cf. Pl. VI. fig. 15). One inexplicable feature is the
long duration of the cartilaginous state of both. Ossification begins in both post-
axially (as is seen in fig. 14 for the carpus), but not until the rest of the limb is fully
ossified.

We have examined both carpus and tarsus at all stages of development back to Q,
where these elements are first chondrified. ‘To make sure of detail, we have employed,
beyond clarified dissections, serial sections cut horizontally.

The Carpus.—Ginther described ten carpal elements, and in this he has been
followed by others. He appears to have missed one of the centralia, and to have
confused the other with the proximal elements, which he describes as five in number
(67. p. 612). Osawa, the latest writer on the subject, correctly records eleven
elements (98%. p. 528), the eleventh being the secend centrale, detected by Bayer
(84. p. 237), who first applied to the parts.a rational terminology. It was, however,
independently discovered by Dollo and Baur (86*. p. 188), the latter opposing Bayer’s
conclusion that its supposed absence is due either to disappearance or union with
another carpal element. In this he was right, for we find it always present.

None of the afore-mentioned observers describe the precise size and relationships
of the two centralia to each other and the adjacent carpal elements. Osawa, however,
gives a very different delineation to the dorsal and ventral aspects of the same pair,
and figures the preeaxial as outwardly extended between the radiale and first carpale as
seen from the dorsal surface (98*. p. 527, figs. 13 & 14). While we can confirm the
accuracy of this, we are able to record further suggestive details. From a comparison
of our figs. 12 and 13 (Pl. VI.) which represent the opposite carpales of the same
individual, we find that the right (fig. 12) is normal but that the left (fig. 13) is
exceptional, in the fact that the preeaxial centrale (pr.c.) is smaller than the postaxial
(po.c.) and lies wholly between the radiale and the first carpale, instead of merely ex-
tending between them. The postaxial centrale, on the other hand, is correspondingly
enlarged, whereby it articulates with the second carpale, as well as with the third and
fourth, to which alone it is usually related. There is thus to be observed an inverse

DEVELOPMENT OF THE SKELETON OF THE TUATARA, 61

proportion to that of the corresponding centralia of the other limb (fig. 12). Bayer has
suggested that in the presence of the double centrale Sphenodon exhibits a Batrachian
tendency, drawing attention to the great extent to which the living Urodela are doubly
centralial. One of us has, with another, attempted to show! that the presence of a
second centrale carpi is a diagnostic character of the Anura, and this goes to support
Bayer’s argument. As to centralia, however, Wiedersheim has demonstrated? the presence
of three in the Axolotl ; and with these facts in mind it occurred to us that the inequality
in development of the two centralia in Sphenodon might possibly be due to the presence
of a third, which had fused with the opposite fellow on the opposite sides in the pair
of limbs under discussion. At Stage Q the condition of the centralia was found to be
the same as in the normal adult; but in a young specimen belonging to the R. College
of Science, Dublin, the preeaxial centrale is on each side ossified from two independent
centres (Pl. VI. fig. 14, pr.c.), and in such a form that while co-ossification of them
would bring about the condition of the right limb (fig. 12), co-ossification of the
middle nucleus with the postaxial centrale (po.c.) would result in that of the left.

Bruhl, for some unaccountable reason, systematically terms? the pisiform of Reptiles
the “ulnar sesamoid”! Concerning the rest of the proximal carpals and the centralia
we have nothing to add.

The distal carpals, stated by Giinther to be five in number, are by Bayer enumerated
as four. As he was dealing with a young animal he found only the 4th carpal ossified.
This is seen to be the case on the left side of our figs. 12 and 13, in which (Stage T)
the rest of the carpus is still cartilaginous (¢f. previous statement on p. 60). Bayer
believed that the 5th carpale is to be sought in the cartilaginous head of the related
metacarpal (op. cit. p. 241); but in this he was mistaken, as pointed out by Baur
in that it is always present and distinct, though small (Pl. VI. figs. 11 to 14).

We have no variations or other matters to record concerning the phalanges of the
fore limb.

The Tarsus.—Ginther describes two proximal and two distal elements, and is doubtful
about a fifth—the fifth tarsal. He alludes without name to the “meniscus” of Born,
which we figure (Pl. VI. fig. 18, mn.). Osawa describes one proximal element, the
“ proximal tarsale,” and four distal—five in all. He regards the meniscus (p. 504) as the
first tarsale, while Born associates it in the Lacertilia* with the centrale. Both are
~ in error, for whereas the meniscus does not appear till Stage S (when all the tarsal
elements have been formed), the first tarsal arises at Q (fig. 16) as a separate element
(I.), and at Stage R, when fully chondrified, unites with its metatarsal. The meniscus is
thus proved to be an accessory element (cf Born, Morph. Jahrb. Bd. vi, 1880, p. 67).

1 Howes & Ridewood: P. Z. 8. 1888, p. 177.

? Wiedersheim, R.: Morph. Jahrb. Bd. vi. 1880, p. 581.

3 Briihl, C. B.: Zootomie aller Thier K]., Wien 1880, pls. 31-34 and 53 & 54,
4 Born, G.: Morph. Jahrb. Bd. ii, 1876, p. 25.

62 PROF. G. B. HOWES AND MR. H. H. SWINNEKTON ON THE

Born, as is well known, gave it as characteristic of the Lacertilia that tarsalia 1
and 2 were probably united with the corresponding metatarsals; and in this he has
been followed by Bayer (p. 243), who claims a phylogenetic union for these! Osawa
rightly figures the second tarsale of Sphenodon as distinct ; and we find that from
Stage Q (fig. 15) to the adult state this is present as an independent element (as in
fig. 18) which becomes extensively ossified.

Perrin asserts (95. pp. 44 & 97) that five separate distal tarsalia are present,
and his figure 9 may illustrate but does not adorn his text! We are at a loss to
understand what he has figured; but one thing certain is that in ascribing three
phalanges to the fifth digit he is im agreement with Bayer, who is inclined to regard
the hooked bone, which by its angulated head articulates with the outer face of the
fourth tarsale, as the fifth of that series. As a salient objection to regarding this as a
metatarsal he seeks to show that on the Giintherian determination Sphenodon would
be an exception to the rule among Lizards in possessing more than three phalanges
to the fifth digit; but it does not occur to him that this statement is tantamount to
admitting that the angulated bone is in most Lizards a metatarsal, and that it thereby
nullifies his argument. Dismissing for the moment the facts of development, the
discovery by us that a specimen preserved in the R. College of Surgeons Museum is
possessed of three phalanges on the outermost digit of one hind limb, and four on the
other, dispenses with the necessity for further discussion of this point, except to remark
that among the Chelonia, Pleurodira (Emydura) for example, we meet with a quadri-
phalangeate fifth toe. The matter is clearly one lying within the range of individual
variation.

Developmentally, this bone, angulated from the first period of its differentiation .
(Stage Q, Pl. VI. fig. 16, v.), ossifies at R (Pl. VI. fig. 17), at the same time and in
the same manner as the other metatarsals; and we have already pointed out that the
tarsal elements do not ossify until T, when the metatarsals are formed. And were
further proof needed of its metatarsal homology, it is forthcoming in the totally
different manner of ossification of the carpus and tarsus and the metacarpals, meta-
tarsals, and phalanges—the former ossifying endosteally, the latter ectosteally.

There is no trace in Sphenodon of tarsale 5 actual or potential, and no evidence
developmentally for the belief of Baur that it is incorporated in the fourth tarsale
(Zool. Anz. Bd. ix. p. 189)1. It seems to have vanished even from the ontogenetic
record.

Concerning the proximal tarsal series, Osawa describes one confluent element; and
Giinther evidently had to deal with a specimen in which they were just uniting, for
the “suture” to which he refers as “scarcely visible ” is recognizable, as in our PI. VI.

1 We are disposed to believe, with Forsyth Major (Trans. Linn. Soc., Zool. vol. vii. 1899, p. 510), that the

compound nature of the “ cuboid” is seriously open to doubt.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 63

fig. 18, in all but old individuals. Bayer, finding the praaxial moiety of the “astra-
galus”” cartilaginous, regarded it as the tibiale, and the whole “ astragalus ” as con-
sisting of the centrale! and the intermedium, the “ calcaneum” being to him the
fibulare (op. cit. p. 243). Perrin, going further, names the “ astragalus”” (op. cit.
p. 44) the “ tibio-centro-intermediare.”

Development at Stage Q shows (PI. VI. fig. 16) that at the chondrification period the
“astragalus” and “calcaneum” are independently chondrified, and a feeble ypsiloid
differentiation (accurately indicated in the fig.) may be observed at what would be
the apposition lines of the tibiale (¢.), centrale (fc.), and intermediare (7.), were they
distinct. In an earlier embryo of the same stage (fig. 15) we found the inter-
mediare (7.) and fibulare (f.) chondrified and separated by a foramen apparently
homologous with that known as the f. arteria perforans mesopodii (f0.), the
centrale (¢c.) and tibiale (¢.) being procartilaginous, although in close apposition with
the intermediare and with each other. Bayer and Perrin had correctly surmised!

7. THe DENTITION.

The detailed study of the tooth-genesis does not fall within the scope of our work,
but we have one or two interesting anatomical facts to record.

Firstly, as to the vomerine teeth. No trace of them in a calcified form is forth-
coming up to Stage 'T, the oldest we have examined. We can add nothing to what is
recorded in the latest account given by Siebenrock?, It may be that we have not
happened to deal with embryos in which they were developing, or, perhaps, that these
clearly vestigial organs attain their full development late.

Baur would seem to be wrong in the surmise (96°. p. 437) that they exist in
young specimens and disappear in old age ®.

The Incisors.—These have been correctly shown by Dendy (99%. p. 77) to be repre-
sented in the young stage by three pairs of “ distinct pointed conical teeth” above and
below, and not by two as believed by Giinther (67. p. 602) and Baur (p. 436). It is
worth remarking, however, that Knox had already recorded the supposed existence of
three pairs in the upper jaw (69. p. 18), and Newman in the lower (77. p. 234), the
former stating that they were confluent at their bases. This is the case at our Stage T

‘ Baur’s passing remark (Zool. Anz. Bd, ix. p. 189) that he found this represented by a piece of cartilage
which was “ eingekeilt ” is suggestive of begging the question.

2 Siebenrock, F.: Transl. cit. p. 309.

s Further search is necessary to ascertain how far the vomerine teeth are or are not represented during
ontogeny, and a former pupil of mine, Mr. H. Spencer Harrison, has undertaken to immediately work out this and
other problems connected with the dentition of Sphenodon as the subject of a special communication to appear
in the Qu. Journ. Microscp. Science.—G,. B. H.

64 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

(Pl. II. fig. 15), the outer tooth of each set being somewhat the larger of the three. At
Stage S (fig. 14) all are seen to be free, and the outer still large. Beyond the mere
inference of fusion, Dendy does not state the method by which he presumes these
pointed incisors to be converted into the tusks of the adult. As a rule each of the
upper tusks, when fully formed, is doubly pointed (or, as remarked by Ginther,
“ notched ”) (ef, text-fig. 15), there being a smaller internal cone, anda larger external
one somewhat backwardly curved (text-fig. 16). In the lower jaw there are three cones
(text-fig. 16), a larger external and two smaller internal, the three teeth which are

Fig. 17.

be
i ‘ SaaS oe
; J i
y, S on

Fig. 18.
L \ ( ! ! /
AS Sai
alii LL
pe Oy

z za ZiL
~— min\ tas Sean

of ieee DRNINVANS) i
i an x ea

\

Ilustrations of the dentition of Sphenodon.

Fig. 15, Incisors, front aspect, old individual. Fig. 16. The same, younger individual, little worn. Both
nat. size. Fig. 17, Enlarged sketch of upper incisors of fig. 16, x 6. Fig. 18. Complete adult dentition :
nat. size. 7, incisors; ¢.a., cheek-teeth, alternating series; ¢.w, cheek-teeth, structurally uniform series.

present having united with the mandible. That portion of the dentary element which
bears them becomes, with them, clothed in an enamel-like substance, which justifies
Giinther’s remark (67, p. 602) that the alveolar edge of the mandible is polished.
Tomes ! regards this substance as true bone.

In the embryonic upper jaw the middle incisor prgsent early ceases to elongate
(cf. Pl. II. fig. 15, tm.) and at Stage T it becomes loose. The reason of this is
evident from the fact that longitudinal section (Pl. II. fig. 16) shows it to be confluent

* Tomes, C.: Dental Anatomy, ed. 4, 1894, p. 253.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 65

only externally with the premaxilla (p.a.) and not by its whole base, as is the case with
the other teeth. We suspect that this tooth is early shed, but unfortunately our material
does not embrace a specimen proving the point.

A possible source of error must not be here overlooked, in the fact that in the adult
there may be present a small pointed cusp (text-fig. 16,*) between the two upper
incisors, which at first suggests a persistent middle tooth. When, however, a tooth
thus constituted is examined under a lens, it is found that the minute cusp has a
counterpart (text-fig. 17) on the inner face of the inner tooth, and that, like this, it
is but the product of its base. And since the teeth, when first formed, are simple
cones, these lesser cusps must be due to secondary complication.

The palatal and maxillary teeth vary very greatly in appearance at different stages in
development and periods of life. One conspicuous feature which has not been recorded
is that at Stage S the maxillary teeth number 11 and the palatal 4-5 (cf Pl. IV.
figs. 4-6). These first-formed cheek-teeth usually alternate, a larger and a smaller
occurring in succession, and not infrequently they may be arranged in recurring sets of
three, a larger and two smaller to each. At Stage T the same numerical condition
obtains (allowing for individual variation, most marked for the palatine teeth), but
under the growth-processes at work the larger teeth have now increased in size.
From this period onwards the numerical increase in the teeth as a whole is due
to superaddition from behind forwards, and most of the teeth thus formed (¢.w., text-
fig. 18) are uniform in size. Numerically they average about 6 on either side, and
for the palate about 4-5, giving a total number of about 16-17 maxillary teeth and
9-11 palatal '.

Passing to the mandibular series, we note an essential similarity to the maxillary, in
the arrangement of the teeth first formed. At Stage S (Pl. IV. fig. 4) there are 11
alternating teeth as in the maxilla’, but no others. On the assumption of Stage T
the teeth of the alternating series, unlike those of the upper jaw, apparently cease to
grow. Wear and tear supervening, and the development of the structurally uniform:
teeth continuing apace, these (t.w., text-fig. 18) become predominant; and hence the
condition herein delineated, which is of short duration, as the teeth of the alternating
series (¢.a.), now insignificant, become rapidly worn down.

Baur has described (95°. p. 436) a Sphenodon skull, 25 mm, in length, having two

» The number of teeth recorded by different observers ranges for the maxillary from 6 (Knox) to 17 (Colenso),.
and for the palatal from 5 (Knox) to 13 (Newman); for the mandibular from 13 (Colenso) to 19 (Giinther).
In the absence of detailed description and knowledge of degree of wear and tear, it is not possible to make
use of these figures. :

? This alternation is a striking feature. Among the Monitors it is often the case that in the fresh state the
cheek-teeth are similarly, though more markedly, alternate, the elongated teeth being fixed to thejaws alternately
with small ones which are freely displaceable at their bases. Can it be that there is a common determining

cause at work here?

VOL. XV1.—ParT I. No. 9.—February, 1901. K

66 PROF, G. B. HOWHS AND MR. H. HU. SWINNERTON ON THE

upper incisors and an eminence which he surmised suggested a third, and he remarked !
that each of the inner incisors on either side had a very small successional tooth, which
he believed was never further developed. On examination of a series of sections of a
19 mm. example we find a similar tooth (Pl. II. fig. 16, ¢d.) but behind the middle
tooth of the three that are present (¢.m.). Baur’s specimen appears to have suffered the
loss of the middle incisor, and to justify our conclusion that this is shed, And while
we are not sure whether our successional incisor is the same as his, or whether he and
we were dealing with members of a series which may be formed, his conclusion that
the tooth is never functional receives support from what we have observed ?.

In describing the cheek-teeth, Baur attributed to the fifth maxillary and the first
mandibular a successional tooth. This we have not been able to confirm. Passing to
the structurally uniform series (¢.w.), we find these to mostly arise lineally. Pl. Il.
fig. 17, in its outlined portion, is a reconstructional drawing from horizontal microscopic
sections at this period. ‘The teeth drawn in outline (¢,/.) are fused to the maxilla and
palatine, as indicated. Those drawn in colour, together with the shaded portion of the
drawing, are from individual sections, the teeth which appear to represent the structurally
uniform series (coloured yellow) being delineated in the position in which they arise.

The teeth of the adult Sphenodon have been defined by Giinther (67. p. 601) as
“ acrodont in the strictest meaning of the term.” Boulenger (Brit. Mus. Cat. cit. p. 1)
regards them as “not implanted in alveoli”; while Tomes, ignoring the incisors, has
written of the post-incisors that they are “acrodont,” and he further suggests that
the glistening investment of the alveolar edges, which Giinther originally described and
showed to “perform the functions of teeth when these are ground down.....
in advanced age,” is true bone. Baur refers (p. 437) to “alveoli ” in his 25 mm.
specimens, but gives insufficient details.

If we may infer from the foregoing that Tomes, ignoring the incisors, was suspicious
of their being in the adult non-acrodont, we have to confirm his doubts. Thanks to
Mr. M. F. Woodward, we have been enabled to examine a series of microscopic sections
of both upper and lower incisors of the adult im sitw; and concerning the upper
there is evidence of surrounding bone—not as the result of a truly thecodont condition,
but of an apparent secondary overgrowth subsequent to the union between tooth and
jaw. Examination of Pl. I. fig. 18 shows in the case of a mandibular tooth that the
truly acrodont condition is assumed at Stage S; and at Stage T the incisors show in
our sections a condition intermediate between this and that above described. Further
investigation of this topic is beyond the limits of our pledge to Professor Dendy,
but, pending detailed study of the tooth-genesis, we would distinguish the condition
occurring in at least the incisors as Ayperacrodont.

1 As usual, he writes (line 8) “ innere ” for ‘‘ aussere.”
2 We have no material to show whether the embryo teeth which we herein describe do or do not become
later replaced.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 67

8. SUMMARY AND CoNCLUSIONS.

Summary.—The following is a summary of the more important conclusions embodied
in Sections 5 to 7 of the present Memoir :—

1. That two kinds of intercentra are formed: primary intercentra, originally paired
and mostly preformed in cartilage; and secondary intercentra, which replace those
throughout certain regions of the body, and are mostly median and arise by direct
ossification outside the vertebral column.

2. That the primary intercentra persist in the caudal region to form the chevrons,
and anteriorly for the first few segments, and that the secondary intercentra coexist
with them in the anterior caudal region alone.

3. That the hyaline cartilages which go to form the vertebral centra are paired in.
origin.

4. That an intravertebral chordal plate is formed by transformation of the sub-
stance of the chorda within each vertebral centrum, and that the plate is continuous
with the chordal epithelium, which becomes converted into a tunica lying inside the
chordal sheath.

5. That during the final differentiation of the vertebrae the chorda becomes
metamerically segmented, and that there appears in each segment a central chordal
vesicle at the point of greatest flexibility.

6. That in that part of the caudal region modified for “ splitting ” there are formed,
by similar differentiation to that which gives rise to the intravertebral chordal plates,
a series of intervertebral plates, and that the intravertebral plates play an important
part in the casting of the tail, and may be possibly the seat of regenerative activity in
the formation of the renewed caudal axis.

7. That the ribs arise in procartilage, in relation to the primary intercentra, with
which they are the first differentiated skeletal elements; and that they are differen-
tiated obliquely, the capitular portions in direct relationship with the intervertebral
regions and the intercentra—the tubercular with the areas of differentiation of the
vertebral centra and arches of the vertebree behind. That these relationships are lost
during later development for all but the third and fourth preesternal segments.

8. That the uncinates are separate in origin, with the possible exception of those of
the penultimate and antepenultimate preesternal ribs.

9. That the cartilaginous brain-case is a product of the union of distinct ethmo-
and orbito-sphenoidal plates, and that its bars and fenestre are all attributable to
direct processes of growth—/. ¢., that it is not a fenestrated cranium of the cartilaginous
fish type.

10. That the hypoglossus nerve-bearing region bears five pairs of nerves with four
pairs of foramina, and that during development these become reduced to two each.

11. That the trabecule cranii play no part in the direct formation of the lateral

cranial wall, and that they represent a pair of preoral visceral arches,
K 2

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68 PROF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE

12. hat the epipterygoid bone is the product of ossification of the ascending process
of the pterygo-quadrate cartilage, and that the special feature of the quadrate bone is
an extension of its ossific head into the latter for approximation to the epipterygoid.

13. That the columella auris and stapedial processes are alike direct derivatives of
the hyoid arch, with which they are continuous at all stages, and that structural
complication is due to overgrowth of the same.

14. That the upper end of the hyoid cornu is attached to the quadrate only, and
that there is a fleeting “jointing ” of the former throughout its course.

15. That in the meeting of the pterygoids and vomers, the latter play a part leading
up to the conditions occurring in the Chelonia and Plesiosauria.

16. The cartilaginous pterygo-quadrate is in its detailed characters most nearly
comparable to that of the Apodal Batrachian Ichthyophis.

17. That each of the three segments of each of the “abdominal ribs” (gastralia)
arises by union of a number of calcifications, and that the median segment may be paired.
That the “ plastron ” is present in a degenerating form.

18. That in their early differentiation the membrane-bones of the head and face are
predominantly circumorbital in position.

19. That there is no supratemporal bone recognizable at any stage as a distinct
element.

20. That the hip-girdle in its development is of a lower type than the Lacertilian,
and that there are two types of pelvis present in adults.

21. That the fifth tarsale has no existence in ontogeny, and that the basal element
of the fifth digit of the hind limb is a metatarsal.

22. That there are apparently three centralia carpi represented during development,
and that a centrale is incorporated in the ‘ astragalus.”

23, That calcified vomerine teeth are not present during encapsulation within the
ege-shell.

24, That of the three pairs of upper incisors, the middle certainly disappear
and the inner may become tricuspid.

25. That the cheek-teeth appear to consist of two series—an early developed
alternating set, and a later posterior and structurally uniform set.

16. That there arise within the occipital region and the individual vertebral segments
‘sustentacular ligaments, for support of the medulla and spinal cord.

Conclusions—Paragraphs 16, 17, 20, and 22 of our Summary add fresh testimony toe
the belief in the Batrachian affinities of the living Sphenodon, while paragraph 15
strengthens the demonstration of its Chelonian resemblances and extends these to the
Plesiosauria. Paragraph 17 proves the creature to be a highly modified representative
of its Suborder, but at the same time to pass through a developmental phase realistic
of the lower Suborder of the Rhynchocephalia, as now classified; and the same is
true of paragraph 24, by comparison with the Proterosauria (especially Paleohatteria).
‘Of the supposed Agamid affinities we have written enough (antea, pp. 4, 22, 46).

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 69

Sphenodon, judged from our standpoint, must be regarded as the surviving represen-
tative of that group of animals ancestral to all the living Sauropsida, and to at least the
Dinosauria, Pterodactyla, and Ichthyosauria, of the past—if not of the Mosasauria and
Dolichosauria also, and unquestionably intimately related to the Anomodontia. As
concerning the unmistakable Stegocephalian affinities of the Rhynchocephalia, it
becomes necessary to enquire more closely than hitherto into the sum of those
characters which constitute a Batrachian a Batrachian—a Rhynchocephalian a Reptile.

Attention was in 1892 called by one of us (Journ. Anat. & Phys. vol. xxvi. p. 402)
to the fact that whereas no Batrachian living or extinct was then known to possess
more than two phalanges on each of its two innermost digits—the formula for the
Class being 2 23 4 2, that of the Sauropsida being 23 45 4 (or something minus that by
reduction), it would seem impossible to derive the Sauropsidan condition from that
of any known Batrachian, not excluding the Stegocephalia. Recent investigation,
however, has modified this aspect of the question. Firstly, there has been discovered
an undoubted Stegocephalian ally having on the second digit of its fore limb three
phalanges and on the third four, and for its hind limb the formula 234431. And,
again, in Credner’s Sclerocephalus of the Permian, which, its massive quadrate notwith-
standing, he places among the Stegocephalia ?, there existed a combination of the lowest
Stegocephalian type, amounting, in the structure of its dermal skeleton, almost to the
‘“‘Ganoidan,” with a limb-skeleton (if the remains are rightly associated) of a veritable
lizard—the phalangeal formula being 2 3 45 4 for the hind limb, and that clawed ®.

Again, as to the sternum, it has also been pointed out by one of us (‘ Nature,’
vol. xlviii. p.269,1891) that a sharp distinction may be drawn between the coraco-sternum
of the Batrachia (an archisternum) and the costal sternum of the Amniota (a neosternum),
the existence of which in any Batrachian or Stegocephalian has not been proved.

And as to the skull, the now well-known fact that whereas in the Amniota the
hypoglossal nerve-bearing region, truncal in origin, is incorporated in the occiput, in
the Batrachia these nerves are postoccipital +, once again opens the gap between the
Batrachia and Amniota—indeed, so markedly, that our ideas may be systematized by

‘ Ceraterpeton galyani, A. S. Woodward, Geol. Mag. (dec. 4), vol. iv. p. 297 (1897).

° Credner, H.: Zeitschr. deutsch. geolog. Gesellsch. Bd. xiv. 18938, p. 639.

3 We are at a loss to understand the reason for the intercalation in the restored portions of the skeleton of
Pariasaurus in the British Museum of Natural History of a fourth phalanx to the second digit of the hind-
limb, especially as in the original description of the specimen it is the front-limb of which it is said (Phil.
Trans. vol. 183, B. p. 363) to be possible that one digit may have nad four! We fail to discover evidence of
more than three phalanges for any digit that is preserved.

* Restricting the terms to the Terrestrial Vertebrata, we leave aside the question how far the vagus-bearing
portion of the skull may be truncal also, and that of the undoubted parallelism which exists between the
Amniota and certain Ichthyopsida, concerning the union of skull and yertebral column (cf. the masterly
Memoir by Fiirbringer, M.: Gegenbaur Festschrift, Leipzig, 1897).

70 PROF, G@. B. HOWES AND MR, H. H. SWINNERTON ON THE

applying to the former condition the term Archicraniate:, and to the latter that of the
Syncraniate.

The characters of the occipital condyle and the presence of one, two, or, for the
matter of that, of three condyles, no longer have the significance once attached to them
as criteria of affinity.

Judged from this point of view, the Rhynchocephalia may well be regarded as a
lowly group, ancestral to the Sauropsida as ordinarily defined, and intimately related
to the Anomodontia; and while the latter, perhaps with or through the Pelycosauria of
Cope, on the one hand gave rise to the Mammalia, they were probably with the Rhyn-
chocephalia derived by diversity of modification from some common ancestral stock
which carries us towards a group which must have been either Batrachian Reptiles or
Reptilian Batrachians, as compared with forms extant—. ¢., they either possessed a
coraco-sternum and an archicranium, or a costal-sternum and a syncranium, structural
combinations which go hand in hand. If they were of the latter type, the living
Batrachia must have suffered the loss of a costal-sternum and not a few of their
distinctive characters must be indicative of retrogression. ‘The argument applies
equally to the quadrate and whether its representative in the living Batrachia is or is
not vestigial, and, as concerning the parasphenoid and pterygoids, the question arises
whether in these ancestral forms they did or did not reach the vomers.

On the other hand, it is possible that, in some manner yet to be discovered, the
ancestral series of Terrestrial Vertebrata may have combined the characters of the later
differentiated forms, as Gadow has surmised in his sagacious remark? that * the
Amphibia and Reptiles do not form a continuous line of development, but are two
divergent branches of a common stock of Paleozoic Tetrapoda.” If, with Credner, we
group together the Stegocephalia and “« Proganosauria” as the “ Eotetrapoda” °, or with
Dawson and Baur‘ associate a no less heterogeneous assemblage under the cognomen
“‘ Microsauria,” we but imply the conviction herein set forth.

Concerning the phalangeal problem, the discovery that certain living Chelonia are
hyperphalangeata®; that by Peters ® that in the Pleurodian Pelomedusa the numerical
reduction of the phalanges is in part due to fusion of more numerous elements during

‘ Sewertzoff writes (Bull. Soc. Nat. Mosc. n.s. vol. ix. 1895, p. 186): “Bei die Amphibien entspricht der
Ganze Occipitalabschnitt einem einzigen Seemente, dein einfachen Occipitalbogen, so dass die Amphibien in
dieser Hinsicht unter allen Cranioten, mit Ausnahme der Petromyzonten, die einfachsten Zustand zeigen.”
Intensely interesting in this association are the recent observations of Peter (op. czt. [antea, p. 50] pp. 590-
592), based on the discovery in Ichthyophis of a postvagal nerve, having, it would seem, an essential similarity
to the “spinal accessory ” of the Amniota.

* Gadow, H.: Phil, Trans. vol. 187. 1896, p. 23.

8 Credner, H.: Allgem. Verstell. naturwiss. Abhandlg. Berlin, Hft. xv. 1891 (‘‘ Naturwiss. Wochenschr.”),
pp. 1-52. a

* Cf. Baur,G.: Anat. Anz, Bd. xiv. 1897, p. 148, and Bd. xi. 1896, p. 657.

* Cf. Boulenger, G. A.: Brit. Mus. Cat. Chelonians, 1889, p. 240, espec. Chitra.

° Peters, W.: Reise nach Mossambique, Zool. iii. Berlin, 1882, p. 6.

DEVELOPMENT OF THE SKELETON OF THE TUATARA. (fal

ontogeny; the investigation of Kiikenthal, which has brought to light the remarkable
fact | that the fourth and fifth digits of the Crocodilian fore limb are developmentally
hyperphalangeate—all testify to the great potentiality of the digital blastema?, and do
away with the value of the mere numerical difference as a criterion of affinity.

The question thus resolves itself into this—are the ‘Terrestrial Vertebrata the
descendants of the afore-defined Batrachian-Reptilia or of Reptilian-Batrachia? The
problem for the immediate future lies in the study of the occiput, the sternal skeleton,
and the quadrate; and, to our thinking, Sclerocephalus, with its multisegmented
and structurally simple ‘“ plastron,” its “fanged” vomer, its elongated dentigerous
pterygoid *, and its quadrate, points the way.

It is certain, but most unfortunate, that in its earliest forms, the sternum, known to
us only in its definitive conditions, was cartilaginous, and has been lost to us in the
paleontological record. The discovery by Osborn, however, of a cartilaginous sternum
in the fossil state4, gives us hope. The decision must lie with the future.
Anatomist and palzeontologist must approach the question in the spirit of a combined
morphological brotherhood; and its solution will mark an epoch in the progress of
the vertebrate morphology of the era of its discovery.

Addendum, Nov. 16, 1900.

Shortly after the proofs of this Memoir were revised for press, there reached us a recently
published paper on the organogeny of Sphenodon, by Professor H. Schauinsland, of Bremen
(Archv. Mikr. Anat. Bd. lvi. pp. 447-867). Although it came to hand too late for comment in
our pages, we observe from its perusal that it is in places erroneous, and that we should have lost
nothing by its earlier appearance, since its author is insufficiently acquainted with the literature
of the subject, and apparently ignorant of the recent important papers by Dendy, now more than
a year old.

List OF THE MORE IMPORTANT MEMOIRS DEALING WITH SPHENODON.

$38, Axprecur, P. Note sur la présence d’un Rudiment de Proatlas sur un exemplaire de
Hatteria punctata. Bull. Mus. Belg. tom. ii. pp. 185-193. (First record of pro-atlas.)

83>. ——. Epiphyses osseuses sur les Apophyses épineuses des Vertébres dun Reptile
(Hatteria punctata, Gray). Bruwelles, 1883. Pp. 1-6.

86, Baur, G. Die zwei Centralia im Carpus von Sphenodon (Hatteria) und die Wirbel von
Sphenodon und Gecko verticillatus, Laur. (G. verus, Gray). Zool. Anz. Bd. ix. pp. 188-190.

‘ Kiikenthal, W.: Morphol. Jahrb. Bd. xix. 1893, p. 50.

2? In a manner akin to that of the passing “jointing” of the hyoid cornu described in the text (antea, p. 48).

> It is unfortunate that its parasphenoid is unknown, but it must assuredly haye possessed one, and that
probably dentigerous.

4 Osborn, H. F.: op. cit. antea, p. 14.

PROF. G. B. HOWES AND MR, H. H. SWINNERTON ON THE

86>, Baur, G. Osteologische Notizen tiber Reptilien. Zool, Anz. Bd. ix. pp. 685-690. (Cf.
Giinther, op. cit. p. 746, and Baur, G., ibid. Bd. x. pp. 120-121.)

86' Osteologische Notizen iiber Reptilien. Zool, Anz. Bd. ix. pp. 733-743.

862, ——, The Ribs of Sphenodon (Hatteria). Amer. Natural. vol. xx. pp. 979-981.

87. ——. On the Morphology of Ribs. Amer. Natural. vol. xxi. pp. 942-945.

88. ——. Osteologische Notizen tiber Reptilien. Zool. Anz, Bd. xu. pp. 40-47. (Para-
sphenoid, epipterygoid, and alisphenoid.)

89. Revision meiner Mittheilungen im Zoologischen Anzeiger mit Nachtragen. Zool.
Anz. Ba, xii. pp. 238-243. (Quadratojugale and otic bones.)

91. ——-. The Lower Jaw of Sphenodon. Amer. Natural. vol. xxv. pp. 489-490.

95%, ——- Ueber die Morphologie des Unterkiefers der Reptilien. Anat. Anz. Bd. xi.
pp. 410=415.

Q5» Das Gebiss von Sphenodon (Hatteria) und einige Bemerkungen iiber Prof. Rud.

Burckhardt’s Arbeit iiber das Gebiss der Sauropsiden. Anat, Anz. Bd. xi. pp. 436-439.

84. Bayer, F. Ueber die Extremititen einer jungen Hatteria. Stzb. Akad. Wien, Bd. xc.
pp. 237-245.

87. Bemmecen, J. F. Beitrage z. Kenntniss d. Halsgegend b. Reptilien. I. Anat. Theil.
Bijdr. t. d. Nied. Dierkd. Ver. Amsterdam, 1887, pp. 102-146. (Contains an accurate
account of nerves, blood-vessels and glands of neck of Sphenodon.)

94. Bere, J. Zur Kenntniss der Briickenechse. Zool. Garten, Bd. xxxv. pp. 102-105 and
pp. 146-150. (An admirable figure of Sphenodon.)

89. Bovienerr, G. A. Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the
British Museum, 1889, pp. 1-3.

91. ——. On British Remains of Homcosaurus, with Remarks on the Classification of the
Rhynchocephalia. Proc. Zool. Soc. 1891, pp. 167-172.
93. ——. On some newly-described Jurassic and Cretaceous Lizards and Rhynchocephalians.

Ann. & Mag. Nat. Hist. (ser. 6) vol. xi. pp. 204-210.

76. Buiter, W. L. Notes on the Tuatara Lizard (Sphenodon), with a Description of a supposed
new Species (S. giintheri). rans. N. Zealand Inst. vol. ix. pp. 317-325.

7. ——. Notice of a new Variety of Tuatara Lizard (Sphenodon) from East Cape Island.
Trans. N. Zealand Inst. vol. x. pp. 220-221. (External characters of a live specimen
described, no name given.)

Further Notes on the Habits of the Tuatara Lizard. Trans. N. Zealand Inst. vol. x1.

pp. 849-351. (Deals with individuals in captivity.)
98. Buscu, C. H. Beitrige zur Kenntniss der Gaumenbildung bei den Reptilen. Zool.
Jahrb. (Anat. Abth.) Ba. xi. pp. 441-499.

85. Corenso, W. Notes on the Bones of a Species of Sphenodon (S. diversum, Col.) apparently
distinct from the Species already known. Trans. N. Zealand Inst. vol. xviii. 1885,
pp. 118-123.

86. Corr, E. D. The Intercentrum in Sphenodon. Amer. Natural. vol. xx. p. 175.

88. Cornet, J. Note sur le prétendu Pro-atlas des Mammiferes et de Hatteria punctata.
Bull. Ac. Belgique (sér. 3), tom. xv. pp. 406-420.

98. Dernpvy, A. Summary of the principal Results obtained in a Study of the Development of
the Tuatara (Sphenodon punctatus). Proc. R. Soc. vol. lxii, pp. 440-443.

998%. ——. Outlines of the Development of the Tuatara (Sphenodon punctatus). Quart. Journ.
Micr. Sci, vol. xl. pp. 1-87.

CON

oon

96".

DEVELOPMENT OF THE SKELETON OF THE TUATARA. 73

Denny, A. On the Development of the Parietal Eye and adjacent Organs in Sphenodon.
Ibid. pp. 111-153.

The Life-History of Tuatara (Sphenodon punctatus). Trans. N. Zealand Inst.
vol. xxxl. pp. 249-255.

Denpy, A.,and Howss, G. B. The Hatching of Tuatara Eggs. Nature, vol. lix. p. 340.

Dotto, L. Notes Erpétologiques. Zool. Anz. Bd. vii. pp. 547-548. (First description of

condylar foramina of humerus. More fully described with figures in Bull. Mus. Belg.
tom. ui. p. 151). (Cf also Fiirbringer, Morph. Jahrb. Bd. xi. pp. 484-486.)

Sur le Proatlas. Zool. Jahrb. (Anat. Abth.) Bd. iii. pp. 433-446.

Fritscu, A. Fauna der Gaskohle und der Kalksteine der Permformation Béhmens, Bd. ii.

Prag, 1889. (p. 58, parasphenoid ; p. 52, cervical vertebre.) (A correction in Zool. Anz.
Bd. x. p. 115.)

Gapow, H. On the Modifications of the First and Second Visceral Arches, with especial
reference to the Homologues of the Auditory Ossicles. Phil. Trans. vol. 179. pp. 451-
485.

On the Evolution of the Vertebral Column of Amphibia and Amniota. Phil. Trans.
vol. 187, B. 1896, pp. 1-57.

——. Gur Rettung von Hatteria. Anat. Anz. Bd. xy. pp. 41-43.

Gorrtr, A. Ueber den Wirbelbau bei den Reptilien und einigen anderen Wirbelthieren.
Zeitschr. wiss. Zool. Bd. |xii. 1897, pp. 343-394.

Gray, J. EK. Note on a peculiar Structure in the Head of an Agama. Zool. Miscell. 1831,
p. 18. (Genus Sphenodon.)

Descriptions of two hitherto unrecorded Species of Reptiles from New Zealand.

Zool. Miscell. 1842, p. 72.

Sphenodon, Hatteria, and Rhynchocephalus. Ann. § Mag. Nat. Hist. (ser. 4) vol. 11.
p. 167. (Gives history of three generic names.)

Ginruer, A. Contribution to the Anatomy of Hatteria (Rhynchocephalus, Owen). Phil.
Trans. vol. 167. pp. 595-629.

Howes, G. B. Pro-atlas and .Vomerine Teeth in Hatteria. Proc. Zool. Soc, 1890,
pp. 857-360.

Huxtiey, T. H. On the Representatives of the Malleus and the Incus of the Mammalia in
other Vertebrata. Proc. Zool. Soc. 1869, pp. 891-407.

Katuius, E. Ueber die Fovea centralis von Hatteria punctata. Anat. Anz. Bd. xiv. pp. 623—
624. (Reply by Osawa, ibid. Bd. xv. pp. 226-227.)

Kraatscn, H. Zur Morphologie der Mesenterialbildungen am Darmkanal der Wirbelthiere.
Morphol. Jahrb. Ba. xviii. pp. 424-433. (Detailed description for Sphenodon.)

Knox, F. J. On the Tuatara (Hatteria punctata, Gray), or Great Fringed Lizard of New
Zealand. Trans. N. Zealand Inst. vol. 11. pp. 17--20.

Maurer, F. Die ventrale Rumpfmuskulatur einiger Reptilien. Festschrift zum siebenzigsten
Geburtstage von Carl Gegenbaur : Leipzig, 1896. Bd. i. pp. 1838-256.

Newman, A. K. Notes on the Physiology and Anatomy of the Tuatara (Sphenodon giintheri).
Trans. N. Zealand Inst. vol. x. pp. 222-239. (Includes description of habits.)

Osawa, G. Beitrag zur feineren Structur des Integumentes der Hatteria punctata. Arche.
mikr. Anat. Bd. xlvu. pp. 570-583.

VoL. xvI.—Part I. No. 10.—Fedruary, 1901. L

99.

90.

93.

DEVELOPMENT OF THE SKELETON OF THE TUATARA.

Osawa, G. Beitriige zur Lehre von den Eingeweiden der Hatteria punctata. Archv. mikr.
Anat. Bd. xlix. pp. 113-226.

Beitriige zur Anatomie der Hatteria punctata (Knochen, Muskeln, Nerven). Archv.
mikr. Anat. Bd. li. pp. 481-691.

—. Beitriige zur Lehre yon den Sinnesorganen der Hatteria punctata. -4rchv. mikr.
Anat. Bd, li. pp. 268-366.

Ueber die Stellung der Hatteria punctata in der Tierreihe. Verhandlg. Anat.

Gesellschaft, 1898 (Anat. Anz. Bd. xiv., Suppl.), pp. 100-106.

Erwiederung an Gadow auf den Aufsatz “Zur Rettung von Hatteria.” Anat. Anz.
Bd. xv. pp. 289-291.

Perrin, A. Recherches sur les Affinités zoologiques de Hatteria punctata. Ann. Sci.
Nat. (sér. 7), Zool. tom. xx. pp. 33-102. (Mainly deals with hind limb.)

Perers, H. W. Remarks on Exhibition of a Specimen of Sphenodon. Stzb. Ges. naturf.
Fr. Berlin, 1870, p. 54.

Ueber die Gehérknéchelchen und ihr Verhialtniss zu dem ersten Zungenbeinbogen
bei Sphenodon punctatus. Monatsber. Ak. Wiss. Berlin, 1874, pp. 40-45.

Reiscuzex, A. Notes on Zoological Researches made on the Chicken Islands, east coast
of the North Island, N.Z. Trans. N. Zealand Inst. vol. xiv. pp. 274-277. (Original
description of supposed commensal habit.)

Résr, C. Beitrige zur vergleichenden Anatomie des Herzens der Wirbelthiere. Morphol.
Jahrb. Ba. xvi. pp. 27-96. (Deals with sinus venosus in detail.)

Rucer, G. Ueber das Peripherische Gebiet des Nervus facialis bei Wirbelthieren. Festschrift
zum siebenzigsten Geburstage von Carl Gegenbaur : Leipzig, 1896. Bd. ii. pp. 195-348.
Scuauinstanp, H. Zur Entwickelung von Hatteria. Stzb. Ak. Berlin, 1898, pp. 629-631.
(Preliminary account on general development, based on material obtained in Cook’s

Island, Dec. 1896 to Jan. 1897.)

Beitriige zur Biologie der Hatteria. Jdid. pp. 701-704. (Breeding-habits and

general development.)

Beitriige zur Biologie u. Entwickelung der Hatteria, nebst Bemerkungen u. d.
Entwickelung der Sauropsiden. Anat. Anz. Bd. xv. pp. 309-334.

Sirsrnrock, F. Zur Osteologie des Hatteria-Kopfes. Stzb. Akad. Wien, Bd. cui. Abth. 1.
pp. 250-268. (English translation in Ann. & Mag. Nat. Hist. (ser. 6) vol. xii. pp. 297-
311.)

Turtentus, G. Vorlaufiger Bericht iiber die Hiablage und erste Entwickelung der Hatteria
punctata. Stzb. Akad. Berlin, Bd. xiv. pp. 247-256. (Apropos of investigations conducted
during 1898-1899 at Te Karewa, St. Stephen’s Island, N.Z.)

Tuomas, A. P. W. Preliminary Note on the Development of the Tuatara (Sphenodon
punctatuin). Proc. R. Soc. London, vol. xlvili. pp. 152-156. (Records sexual differences

and gives a description of the egg.)

Warp. ‘The Hatteria (Sphenodon) punctatus.” Nat. Sci. Bull. vol. i. 1882, pp. 14-15.
(Mainly a popular account of an expedition to obtain the living animal.) (French
translation by Bonnier in Bull. Sci. Dép. Nord, tom. xix. pp. 89-97.)

Werner, F. Beobachtungen an Sphenodon (Hatteria) punctatus. Zool. Garten, Bd. xxxiv.
pp. 835-339. (Observations on an adult in captivity.)

arn)

et)
Peps

76

DEVELOPMENT OF THE SKELETON OF THE TUATARA,
EXPLANATION OF THE PLATES1.
PLATE I

SPHENODON PUNCTATUS.—VERTEBRAL COLUMN AND RIBS.

a., arch of the atlas; a., body of atlas (odontoid peg) ; ¢.¢., caudal canal; ¢.v., cartilaginous
vertebra ; /./., fibrous tissue; /.a., accessory hypapophysis ; i.p., primary intercentrum ; 7.p.', median
intercentrum ; 7.p./, chevron-bone; 7.s., secondary intercentrum ; i.sg., interseptal segment ;

my., myelon (spiual cord) ; ”.a., neural arch; ne., notochord; ne.e., chordal epithelium; ne.s.,
chordal sheath ; n.p., intravertebral chordal plate ; ».p.’, intervertebral chordal plate; n.sp., neural

spine; 0¢.c., occipital condyle ; 0.v., osseous vertebra; 7.cd., caudal rib; 7.s., sacral rib; r.t., trunk

rib; s./., splitting lamina; s.0., skeletogenous sheath; ¢.a., interarticular tissue; v.c., vesicula

centralis.

Vig.

Fig.

Fig.

Fig.
Fig.
Fig.

Fig.

Ie

Or

“NI

9.

5 AAR

18.
1),
20.

2l.

Staye P. Vertebral Column :—Uateral longitudinal section at about the region of

vertebrae 6-8. x 50.
Staye P. The same :—Median longitudinal section through the region of fig. 1. x 50.
Stage P. The same :—Transverse section through the intervertebral region of caudal

segments 2-3. x 40.
Stage P. The same :—Section through a vertebral region—the 6th segment in front of
fig. 3. x 40.
Stage Q. Vertebral Column :—Uateral longitudinal section in the region of vertebree
20-23. x 40.
Stage Q. The same :—Median longitudinal section through vertebree 20-23. x 40,
Stage Q. The same:—Longitudinal section (slightly oblique) through caudal vertebrz
3-6. x 40.
Stage Q. The same :—Median longitudinal section through the basi-occipital and the
four anterior cervical vertebree. x 40.
Stage S. Vertebral Column :—ULongitudinal section through the basi-occipital and the
three anterior cervical vertebre. x 25.
Stage S. The same :—Median longitudinal section through vertebre 13-15. x 20.

Stage S. The same :—Transverse section through the intervertebral region 5-6. x 25.
Stage S. The same :—Ventral aspect of the last presacral to the 9th caudal vertebre

showing free caudal ribs. x 5.
Staye T. Vertebral Column :—Median longitudinal section through vertebre 7-10. x 18.
Stage T. The same :—Median longitudinal section through intercentrum 8-9 of fig. 13,

showing minute structure. x 50.
Adult. Vertebral Column :—Median longitudinal section through vertebre 9-11. x 11.
Adult. The same :—Ventral aspect of the 10th to the 20th vertebra showing an abnormal

condition of the intercentra. ? nat. size.
Adult. The sume :—Median longitudinal section at about the region of the 12th caudal

vertebra. x iy
Adult. The same :—Caudal vertebre 7--12 from the left side. ? nat. size.
Adult. The same :—Transverse section through plane a-d of fig. 17. 6 thle
Adult. The same :—Caudal vertebra 11 from the left side. $ nat. size.
Adult. The same :—Caudal vertebre. ? nat. size.

* In all the Plates, where colouring has been employed, blue indicates hyaline cartilage and yellow bone,
with the exception of Pl. I, fig. 13.

Trans. Loot, Soc. Vol XV. TEI.

HLELS, del. cr
M.-P, Parker ith. Geo. West & Sons imp

SPHENODON PUNCTATUS.
Vertebral Column & Ribs.

PLATE I

‘ te aa

—~T
io 2)

DEVELOPMENT OF THE SKELETON OF THE TUATARA.

PLATE II.
SPHENODON PUNCTATUS.—VERTEBRAL COLUMN AND RIBS, GASTRALIA, AND TEETH.

a., arch of atlas ; ab.’, abdominal rib, median portion ; ab.", abdominal rib, lateral portion ;
c.au., auditory capsule; d., dentary; ¢.0., exoccipital; g.t., gastralia tissue tracts; z.p.', median
intercentrum; ip.", chevron-bone; m., costo-cervical muscle; m.', ligament of costo-cervical
muscle; mk., Meckel’s cartilage ; ma., maxilla; my., myelon (spinal cord) ; x./, first spinal nerve ;
nit. twelfth cranial nerve; n.a., neural arch ; ne., notochord; nc.e., chordal epithelium ; nc.s.,
chordal sheath ; n.p., intravertebral chordal plate ; n.s., neurocentral suture ; 0.v., osseous vertebra ;
p.a., pro-atlas ; pe., premaxilla; 7.¢., cervical rib; r.cd., caudal rib; 7.s., sacral rib; r.¢., trunk rib ;
t.a., interarticular tissue; ¢.ch., cheek-tooth ; ¢.d., developing tooth; ¢,f., fully-formed tooth (fused
with bone); ¢.i., inner incisor; ¢.m., middle incisor; ¢.0., outer incisor; ¢.p., transpalatine ;
u.p., Uncinate process.

Fig. 1. Stage S. Anterior cervical vertebra :—The first five vertebree showing anterior cervical

ribs, lateral aspect. x 8.
Fig. 2. Stage T. The same :—The first 5-6 vertebree showing osseous and so-called ligamentous
cervical ribs from left side, ventro-lateral aspect. x 4,

Fig. 8. Stage S. The “ Pro-Atlas” :—ULateral longitudinal section, including the exoccipital.
; x 20.
Fig. 4. Stage S. The Ribs :—Transverse section of last presacral vertebral segment. x 20.
Fig. 5. Stage S. The same :—Transverse section of the second sacral vertebral segment. x 20.
Fig. 6. Stage S. The same :—Transverse section of the fourth caudal vertebral segment. x 20.
Fig. 7. Stage R. Uncinate process :—Section through a poststernal rib showing development of
uncinate process. x 25.
Fig. 8. Stage S. Abdominal ribs :—Ventral aspect of ribs 3-5. x 8.
Fig. 9. Stage S. The same :—Ventral aspect of ribs 16-18 of right side. x 11.
Fig. 10. Stage T. The same :—Ventral aspect of ribs 7-16 showing irregular union of parts. x 2.
Fig. 11. Stage R. Notochordal plate :—Transverse section showing first origin. x 40.
Fig. 12. Stage S. The same :—Transverse section at full formation. x 25.
Fig. 18. Stage S. Chevron-bones :—Transverse section showing attachment to fourth caudal
vertebra. x6
Fig. 14. Stage S. Incisor teeth :—Front aspect. x 5.
Fig. 15. Stage T. The same :—Front aspect. x 4,
Fig. 16. Stage T. The same:—Median longitudinal section through second upper incisor and
, associated parts. xX 23.
Fig. 17. Stage T. Mavillo-palatine teeth :—Combined drawing—the teeth already confluent with
the bone being indicated in outline, the developing teeth in colour. 4 Iho

Fig. 18. Stage S. Check-tooth :—Transverse section, including dentary and Meckel’s cartilage.
x 20.

Trans. Loot. Soc. Vol XVI. Tb Il

c.aw.

HH,S. del.
MP, Parker lith Geo. West &

& Sons imp

SPHENODON PUNCTATUS.
Vertebral Column & Ribs, Gastralia & Teeth.

ie

Ul epee

me

PLATE Lia

80 DEVELOPMENT OF THE SKELETON OF THE TUATARA.

PLATE III.
SPHENODON PUNCTATUS.—DEVELOPING SKULL, EARLIER STAGES.

The figures on this Plate are of wax models reconstructed from microscopic sections,
the skeletal parts being alone represented. ‘The fenestrae and interspaces in the
chondrocranium are for the most part occupied by membrane (not indicated), except
in so far as they transmit nerves and blood-vessels (¢f. Pl. 1V. fig. 10).

an., angular; ar., articular; 0.s.', basipterygoid process; c¢.', anterior semicircular canal ;
c.au., auditory capsule; ¢.r., coronoid ; d., dentary ; ¢.c., extrastapedial cartilage ; ¢.n., external
nares ; €.0., exoccipital; epg., epipterygoid ; e.s., ethmosphenoidal plate; ev., extranasal; ex.'“,
extranasal processes ; f.i.—vii., foramina for exit of cranial nerves; f.a., foramen for ophthalmic
branch of the carotid; f.e., ethmoidal foramen; /.2., interorbital fenestra; f7., foramen for jugular
vein; f.m., foramen magnum; f.n., lateral cranial fenestra; fr., frontal; h., hyoid; A.’, anterior
cornu of the hyoid ; h.", posterior cornu of the hyoid; i.m., internal nares; j., jugal; mk., Meckel’s
cartilage; mz., maxilla; ma.’, maxillary process; n.a.p., alinasal process ; c., notochord; n.c., nasal
capsule; n.c.', supranasal process; n.c.", prenasal process; 7.f.', nasal fenestra; n.pa.p., naso-
palatine process; 2.p.p., naso-premaxillary process; ns., nasal; .v.p., mferior naso-vomerine
process ; 0c.c., occipital condyle; os., otosphenoidal plate ; os.‘°, otosphenoidal processes ;
p., parietal; pa., palatine; par., parachordal; p.f., prefrontal; py., pterygoid; pg.’, pterygoid
process ; p.o., postorbital ; po.f., postfrontal; p.p., parotic process; p.g., pterygo-quadrate :
ps., presphenoidal cartilage ; p.s., parasphenoid ; pa., premaxilla; py.', pituitary foramen ;
q-, quadrate ; q.’, otic process of quadrate; q,j., quadrato-jugal ; s.a., supra-angular; sb., subnasal ;
S.i., interorbital septum; s.mz., septo-maxillary; s.0.’, supraoccipital cartilage; sp., splenial ;
sq., squamosal ; sq.’’, posterior process of squamosal ; s.s¢., suprastapedial cartilage ; s¢., stapes ;
t.p., transpalatine; ¢r., trabecula; vo., vomer.

Fig. 1’. Stage P. Developing chondrocranium :—Left lateral aspect. The arrow indicates the

direction of the longitudinal axis of the embryo as it lay coiled. x 13:
Fig. 2*. Stage P. The same :—Ethmoidal, trabecular, and sphenoidal regions, dorsal aspect. x 13.
Fig. 3°. Stage P. The same :—Parachordal and auditory regions, dorsal aspect. x 13.
Fig. 4. Stage Q. Developing chondrocranium :—Lateral aspect. x 8.
Fig. 5. Stage Q. Developing skull :—Lateral aspect. x 8.
Fig. 6. Stage Q. Developing chondrocranium :—Veutral aspect. x 8.
Fig. 7. Stage Q. The same :—Dorsal aspect. xo:
Fig. 8. Stage R. Developing chondrocranium :—Lateral aspect. &¢ i
Fig. 9. Stage R. Developing skull :—Posterior aspect. Xe th
Fig. 10. Stage R. The same :—Lateral aspect. x 8.
Fig. J1. Stage R. The same :—Dorsal aspect. x 8.
Fig. 12. Stage R. The same :—Veutral aspect. x (he

* In these figures the uncoloured areas represent pro-cartilage.

Trans. Loot. Foc. Vol XV. TC AL

H.H.S, del.
M._P; Parker lith. Geo, West & Sons imp.

SPHENODON PUNCTATUS.
Developmg skull, earlier stages.

}

“you. XVIL—PAR I. No. 11.----February, 1901.

82 DEVELOPMENT OF THE SKELETON OF THE TUATARA.

PLATE IV.
SPHENODON PUNCTATUS.—DEVELOPING SKULL, LATER STAGES.

an., angular; ar., articular; .0., basi-occipital; .s., basisphenoid; 4.s.', basipterygoid
, posterior semicircular canal; c¢7., coronoid ;

u"

process; c.', anterior semicircular canal; c.
d., dentary ; e.c., extrastapedial cartilage ; e.n., external nares ; ¢.0., exoccipital ; e.p.g., epipterygoid ;
e.s., ethmosphenoidal plate; ea., extranasal; ew.'-ex.’, extranasal processes ; /. 7.—vii., foramina for
exit of cranial nerves (f., fenestra in the suprastapedial cartilage; /.c., ethmoidal foramen ;
fi. interorbital fenestra ; fy., foramen for jugular vein; f.n., fenestra in the anterior wall of the
brain-case; f.p., parietal foramen; fr., frontal; h.’, anterior cornu of the hyoid; z.7., internal
nares; j., jugal; dd., lachrymal duct; mk., Meckel’s cartilage; mp., meniscus pterygoideus ;
mx., maxilla; ma.', maxillary process; 2. v., vi., cranial nerves; n.c., nasal capsule ; 2.c.', supra-
nasal process ; 7.c.”, prenasal process ; n/.’, nf.’’, nasal fenestre ; ns., nasal; oc.c., occipital condyle ;
op., opisthotic ; 0.s., otosphenoidal plate ; 0.s.'", otosphenoidal processes ; p., parietal ; pa., palatine ;
pF.» prefrontal ; p.g., pterygoid ; p.g.’, pterygoid process ; p.o., postorbital ; po,f., postfrontal ; p.p.,
parotic process; pro., prootic ; ps., presphenoidal cartilage ; p.s., parasphenoid ; pz., premaxilla ;
py., pituitary body; q., quadrate; q.’, otic process of quadrate; q,j., quadrato-jugal ; s.a., supra-
angnlar; s., subnasal; s.i., interorbital septum; s.mz., septo-maxillary; s.0., supra-occipital ;
s.o.!, supra-occipital cartilage ; sp., splenial; sg., squamosal ; sq.’, anterior process of squamosal ;
sq.', posterior process of squamosal: s.st,, suprastapedial cartilage; s¢., stapes; ¢f.p., trans-
palatine ; vo., vomer.

Fig. 1. Stage R-S. The head :—Transverse section through epipterygoid region (y-6 of fig. 4).
x 6.

Fig. 2. Stage R-S. The same :—Combined figure of two transverse sections through the nasal
region (a-8 of fig. 4), the left half several sections in front of the right. x 15.

Fig. 3. Stage R-S. The same :—Transverse sections showing detailed relations of pterygoid and
basisphenoid (seven sections in front of fig. 1). x 18.

Fig. 4. Stage 8. Developing skull :—Lateral aspect. x 5.
Fig. 5. Stage S. The same :—Dorsal aspect. x 5.
Big. 6. Stage S. The same :—Ventral aspect. x 5.
Fig. 7. Stage S. The same:—Posterior aspect. x 5.
Wig. 8. Stage T. Developing skull :—Dorsal aspect. x 3.
Fig. 9. Stage T. The same :—Posterior aspect. xX 3.
Nig. 10. Stage T. The chondrocranium :—With endostoses and the parasphenoid; as seen after

removal of the mandibular skeletal arch. Left lateral aspect. x 3.

Mig, ll. Stage T. The left pterygo-quadrate arch and squamosal :—Lateral aspect. x15:

Trans. Loot. Soc. Vl. XVI. TCI.

ema ieee rca .
OP. €0. bo, $0. $0. Pp.

H.H.S. del.
M-P.-Parker lith. Geo, West & Sons imp

SPHENODON PUNCTATUS.
Developing skull, later stages.

84 DEVELOPMENT OF THE SKELETON OF THE TUATARA.

Led b/ MN) \%
SPHENODON PUNCTATUS.—THE QUADRATE, HYOID, AND COLUMELLA AURIS.

an., angular; ., boundary between stapes and extrastapedial cartilage ; 6.a., branchial arch ;
b.c., branchial cleft ; ¢.!", horizontal semicircular canal ; ca., carotid artery ; ca.’, branch of carotid
artery; ¢.au., auditory capsule ; e.c., extrastapedial cartilage ; ew., eustachian recess; fe., fenestra
in suprastapedial cartilage; /.', anterior cornu of the hyoid; j.v., jugular vein; mk., Meckel’s
cartilage; mt., mouth; x. v.-ai., cranial nerves ; x. vii.', branch of chorda tympani; ph., pharynx ;
p-p-, pavotic process ; py., pterygoquadrate; g., quadrate ; q.’, otic process of quadrate; s.a., supra-
angular ; sq.!, anterior process of squamosal; sg.", posterior process of squamosal; s.st., supra-
stapedial cartilage ; s¢., columella (stapes) ; sé’, boundary between columella and extrastapedial
cartilage.

Figs. 1-5. Stage P. A series of sections, in order from within outwards, showing the primary
relationships of the columella auris to the hyoid and quadrate. x 40.

Fig. 1. Represents the most internal section No. 1.
Fig. 2. Represents section No. 6.
Fig. 3. - » INO; os
Vig. 4. 30 5 NOs 1s
Bie 5. ue NOs 27%
Fig. 6-11. Stage Q. A similar series to the above. X 20
Fig. 6. Represents the most internal section No. 1.
Fig. 7. Represents section No. 11.
Fig. 8. bp pe NOn 26:
lays, @); 3 Pe Nowe.
Fig. 10. » No. 46.
Fig. 11. 5 SENOS
Fig. 12. Stage R. Transverse section of auditory region passing through quadrate and columella
auris. x 25,
Figs. 13-14, Stage S. Sections, in the same order as figs. 1-5, showing the relation of the
suprastapedial cartilage to the quadrate. x 20.

Fig. 13. Represents the more internal section No. 1.
Fig. 14, Represents section No. 16.

Ut XVI. FZ%.V.

U.

Trans. Loot. Io

HHS. del.

Geo, West & Sons imp

M.-P. Parker lith.

SPHENODON PUNCTATUS.

The Quadrate, Hyoid, & Columella auris

PLATE

: VOL, XVI.—PART ils No 12.— February, 1901.

si

Sb DEVELOPMENT OF THE SKELETON OF THE TUATARA,

PLATE VI.
SPHENODON PUNCTATUS.—CRANIO-FACIAL MEMBRANE-BONES AND APPENDICULAR SKELETON.

ac., acetabulum; an., angular; ¢., centrale; ¢.i.p., ischio-pubie cartilage; cl., clavicle ;

cor., coracoid ; cor.', sulcus coracoideus ; cor.", foramen for supracoracoideus nerve; d., dentary ;
é., epipubis ; ep., epiphysis; 7”, fibula; /\, fibulare ; /.6., foramen for arteria perforans mesopodii ;
fc. foramen cordiforme ; f.ec., ectepicondylar foramen ; f.en., entepicondylar foramen ; f.0., obtu-
rator foramen; fr., frontal; g,f., glenoid fossa; hp., hypoischium ; 7., intermedium ; i.c., mter-
clavicle; i/., ilium; is., ischium; 7., Jugal; /éip., ischio-pubic hgament (ligamentum medianum
pelvis) ; m.i., metischial process ; mn., meniscus tarsale; mz., maxilla; ma.’, maxillary process ;
ns., nasal; p., parietal; pa., palatine; pb., pubis; pb.’, prepubic process; p.f., prefrontal ; pg.,
pterygoid; pi., pisiform; p.o., postorbital; po.c., postaxial centrale; po.f., postfroutal; pr.c.,
preaxial centrale; pro.t., proximal tarsal; pa., premaxilla; q.j., quadrato-jugal; R., radius;
rd., vadiale ; 7.¢., trunk rib; s.,sternum; s.a., supra-angular; sc., scapula; se.', acromial process ;
sc, suprascapula ; se., sesamoid; s.mz., septo-maxillary ; s.n., poststernal notch; sp., splenial ;
sq., squamosal; sg.'’., posterior process of squamosal; 7., tibia; ¢., tibiale; ¢.c., tarsal centrale ;
i.p., transpalatine; U., ulna; w., ulnare; vo., vomer; I.-V., metacarpals and metatarsals ;
1-5, carpals and tarsals.

Tig. 1. Stage 8S. The membrane-bones :—Bones from roof of skull and side of head. a)
Pig. 2. Stage S. The same :—Bones from roof of mouth. x 5.
ig. 38. Stage S. The same:—Bones from lower jaw. x5)
Vig. 4. Stage Q. Pectoral girdle and sternum:—Lonugitudinal section with developing clavicle.
x 25.

Mig. 5. Staye R. Pectoral girdle and sternum :—Ventval aspect. Ks
Fig. 6. Stage T. Pectoral girdle and sternum :—Ventral aspect. x 2.
Vig. 7. Stage Q. Pelvic girdle :—Ventral aspect (from wax model). x 8
Fig. 8. Stage R. Pelvic girdle :—Ventral aspect. x a.
Fig. 9. Stage T. Pelvic girdle :—Ventral aspect. x 2.
Fig. 10. Stage Q. Humerus :—Distal end, ventral aspect (from wax model). x 1d.
Fig. 11. Stage Q. Right carpus :—Horizontal section. x 20.
Pig. 12. Stage T. Right carpus :—Dorsal aspect, showing normal condition of centralia. x 4.
Fig. 18. Stage 7. Left carpus :—Dorsal aspect, showing abnormal condition of centralia from
same animal as fig. 10. x 4.

Pig. 14. Small Adult. Right carpus :—Dorsal aspect. x 2.
Fig. 15. Stage Q. Left tarsus :—Farly period, horizontal section. x 20.
Fig. 16. Stage Q. Right carpus :— Late period, horizontal section. x 20:
Fig. 17. Stage R. Left tarsus :—Horizontal section. xaos
Pig. 18. Adult. Right tarsus :—Dorsal aspect. X 2.
Big. 19. Adult. Portion of left tarsus :—Dorsal aspect, showing ulnar sesamoid. x 2.

Trans. Loot. Soe. Vol XVI. TE VI.

Ss

prot. —/------

HHS. del.
MP.

Parker lith. Geo West & Sons imp
SPHENODON PUNCTATUS.
Cranio-facial membrane bones, & Appendicular Skeleton.

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T. On the Development of the Skeleton of the Tuatara, Sphenodon punctatus ;
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By G. B. Hows, LLD., PRS. and H. H. Swinnerton, B.Se., Marshall
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Il. Contribution towards a Knowledge of the Osteology of the Pigmy Whale (Neobalena
marginata). Sy Frank E. Bepparp, W.4., F.RS., Prosector and Vice-Secretary
of the Society.

Received May 23, read November 20, 1900.

[Puares VIT.-IX.] =

‘THE earliest description of any part of this Whale is, so far as I am aware, to
be found in Dr. Gray’s account of the Cetacea collected during the voyage of the
‘Erebus’ and ‘Terror’'. In that memoir he described and figured the baleen of the
creature, which was known from three plates, obtained off Western Australia, and
now in the collection of the British Museum. ‘These measured 20 inches in length,
and were noted as remarkable on account of their “ pure white” colour. The baleen,
Dr. Gray remarked *, ‘‘is much smaller and broader compared with its width at the
base than, and is different in colour from, the baleen of any of the other species [of
Balena|.” He adds to this that it “is of nearly the same structure as that of the
Greenland whale.” Dr. Gray’s descriptions of new forms of whales, based upon
fragmentary portions of their hard parts, were seldom so fortunate as this particular
identification of the plates of whalebone with an animal unknown to science. It was
by him retained in the genus Lalwna in the ‘ Catalogue of Seals and Whales.’ Gray
was fully justified, and not long afterwards, by further discoveries of this whale.

In 1869 Hector? described and figured a skull of a young example of the same
whale. Upon this skull Dr. Gray founded a new genus for its reception, to which he
gave the name of Neobalena*.

Later on Sir James Hector appended some ‘“ Notes on the Cetacea in the Colonial
Museum, Wellington,” to a paper by Dr. Knox “On the Balzenidee, or Whales with
Baleen” °. In the course of these notes upon the subject of the present article
measurements and figures of the skull of Neobalena were given, and the author
identified the animal with that originally described by Gray in the following concluding

1 Zoology of the ‘ Erebus’ and ‘Terror,’ 1846, p. 48, pl. i. fig. 1. See also Cat. Cetacea B. M. 1850, p. 14,
and P. Z. 8. 1864, p. 200.

2 Catalogue of Seals and Whales in the British Museum, 1866, p. 90.

° Trans. New Zealand Inst. ii. p. 26, pl. 11. B. figs. 1-4. See also Ann, Nat. Hist. v. p. 221, and vi. p. 155,
figs. 1 & 2.

* Supplement to the Catalogue of Seals and Whales, 1871, p. 39.

> Trans. New Zealand Inst. ii. p. 21.

VOL. Xvi.—Part 11. No. 1.— August, i901. )

88 MR. I. E. BEDDARD ON THE

sentence to his essay :—‘ From the character afforded by the baleen of this specimen I
conclude that it is the head of the Balana marginata, Gray, or West Australian
Whale.”

The skull is figured in three views, and there can of course be no doubt that the
identification of Hector was perfectly true.

In a contribution to the same journal as that from which we have just quoted,
Dr. Gray ! gave some further notes upon Balena marginata, establishing it as the type
of his new genus Weolalena. The paper is reprinted from one published in the
Annals & Magazine of Natural History’*, and is reproduced in Dr. Gray’s full
account of Neobalena in the ‘Supplementary Catalogue of Seals and Whales in the
British Museum.’

Dr. Gray had evidently some justification for pointing out that his separation of the
whale by the characters of its whalebone have been fully borne out by the characters
of the skull as described by subsequent observers. It is doubtful, however, whether
this position is strengthened by his statement that “ Physalus antarcticus,” also differ-
entiated by the characters of its whalebone, has turned out to be a distinct form of
Rorqual.

Dr. Gray’s definition of the genus, founded upon the skull and the whalebone, was
as follows :-—

“Skull rather depressed ; brain-cavity nearly as long as the beak, depressed, much
expanded at the sides, with a very deep notch on the middle of each side over the
condyles of the lower jaw, and with a subtriangular crown-plate. ‘The nose as broad
as the expanded brain-cavity at the base, attenuated to a fine point in front and slightly
arched downwards. Lower jaw laminar, compressed, high; the upper edge thin, and
inflexed the greater part of its length, erect in front ; the lower edge inflexed in front,
the rest of the edge being simple. The baleen elongate, slender, several times as long
as broad, with a fringe of a single series of fine fibres; enamelled surface smooth and
polished, thick.”

The skull to which this description refers is that described by Sir J. Hector, and
was obtained on the island of Kawau near New Zealand. The figures given by Hector
are reproduced by Gray in his ‘Supplementary Catalogue.’ It is an incomplete skull
wanting the end of the snout and the lacrymal bone.

A few years later another skull was described by Sir James Hector? from the
Auckland Museum. It was that of “a young calf,” and measured 2 feet 11 inches.
The baleen is described as “ yellowish white.” Hector observes that the whale

‘ « Notes on the Skull of Balena marginata described in the Transactions of the New Zealand Institute,
vol. ii. p. 21, as the type of a new Genus Neobalena,’ Trans. New Zealand Inst. ii. p. 123.
2 1870, vol. v. p. 221, and vi. p. 155, figs. 1 & 2.

“ Notes on New Zealand Whales,” Trans. New Zeal. Inst. vii. 1875, p. 251.

OSTEOLOGY OF THE PIGMY WHALE. 89

“appears to be found on all parts of the coast, but is described by the whalers as of
rare occurrence.” It was held by one “qualified informant” to be identical with
the rather mysterious “Scrag Whale,” a creature which has not been satisfactorily
identified with any known form. I hope, however, on a future occasion to have the
opportunity of saying something about the latter whale, which may be the Grey Whale
of California.

Some little confusion as to possible synonyms of this whale has been introduced by
Dr. Gray. In a paper dealing with British Cetacea (the italics are necessary) the
author adds some details’ to his earlier notes? on the so-called Balena (Caperea)
antipodarum.

These details consist in a description of the tympanic bones of a Balwna identified
with that species, which were received from Otago, New Zealand. Nothing is there
said of the size of these bones. The figures were subsequently copied into the
‘Catalogue of Seals and Whales’ *, but again without measurements. ‘These ear-
bones, however, were regarded as those of a specimen 60 feet long, to which dimensions
it does not appear at all likely that Meobalena marginata ever arrives. Yet in a third
reference to this ear-bone, Dr. Gray, though quoting Hector‘ to the effect that it
belongs to Neobalena, refers to a skeleton in the Paris Museum as wanting the ear-
bones and as being that of a Eubalena antipodarum. The coincidence—not very
remarkable—seems hardly worth mentioning, since it was perfectly apparent that there
could be no conceivable confusion between the two whales from the investigations of
van Beneden and some others who are duly quoted by Gray.

Having thus entered into the matter of the ear-bone, stated by Hector to be that of
Neobalena, Dr. Gray unexpectedly observes: “In these remarks I have taken no
notice of the Pigmy Right Whale (Neobalena marginata) found in New Zealand and
West Australia, because that is at once known from all the others by its small size.”

On a later page (P. Z. S. 1873, p. 143), however, the synonymy is correctly ®
given as:

Neobalena marginata, Gray, Cat. Seals and Whales, p. $0, &c., &c.
Caperea antipodarum, Gray, ibid. p. 101.

In the paper which has just been quoted, Hector refers to a description, contained
in a letter written to him by Mr. Traill, of the external characters of this whale, as he
correctly assumed and later on proved it to be. It was captured among a large school of

* “On the Cetacea which have been observed in the Seas surrounding the British Islands,” P. Z. S. 1864,
p. 195.

* Loology of the ‘ Hrebus’ and ‘ Terror,’ and in Dieffenbach’s ‘ New Zealand,’ p. 101.

* “ Notice of a Skeleton of the New Zealand Right Whale, &c.,” P. Z. S. 1873, p. 133.

* Ann. & Mag. Nat. Hist. 1873, vol. xi. p. 108.

° Correctly, that is to say, as regards specific name: for on the page of the Catalogue first quoted it is called
“ Balena marginata.”

0 2

90 MR. F. E. BEDDARD ON THE

Blackfish—a somewhat vague term for a whale, but apparently here meaning a species
of Globicephalus. The animal was 15 feet 5 inches in length, and of a black colour
with a light stripe on the belly. The rest of the description may be given in Sir
James Hector’s own words :—*‘ Pectoral fins situated immediately behind the head,
each being 1 foot 3 inches long. 230 plates of baleen on each side, the largest being
18-5 inches by 1-8 inches at base and 0:1 inch thick ; colour of baleen yellowish white
with a dark margin. The ribs are at least seventeen pairs, and are very oblique.
Most of them are nearly straight, broad, and flat, and very small towards the point of
attachment, the form being suggestive of short swords or paper-knives, and from their
shape and light curvature very unlike ribs. The sternum is singular, bearing a striking
resemblance to a scutcheon, and appearing to have had only one rib-attachment on
each lateral border. The seven cervical vertebre were thoroughly ankylosed.”

Mr, Traill held the whale to be a Finback (= Balenoptera), apparently because of
the dorsal fin, to which Sir James Hector does not allude in his transcription of
Mr. Traill’s remarks, but refers to afterwards in characterizing the whale. The
skeleton of this individual came later into Hector’s hands and was briefly described by
him with a number of illustrations in a “ Postscript” to thesame paper. The skeleton
did not, however, arrive in a complete condition, as is evidenced by the fact that
Hector only deseribes 15 pairs of ribs, while Traill asserted that there were 17 at least.
This skeleton is now in the Natural History Museum in London. A large number of
the important points are noted by Sir James Hector. I have, through the kindness of
the Director of the Natural History Museum, been able to study this example and also
a much finer and apparently adult or nearly adult whale of the same species. This
specimen was purchased in January 1886 of Dr. Julius v. Haast. Upon both of these
some few notes have been made and published by Sir William H. Flower and Mr. R.
Lydekker in their ‘Mammals Recent and Extinct. I have myself dealt briefly with
this form in ‘ A Book of Whales’ !.

The skeleton described by Sir James Hector is so clearly that of a young animal,
that it would be impossible, or at least not at all desirable, to draw from its study a
final definition of the characters of this remarkable genus. Some of the characters are
plainly due to immaturity and would deceive no one ; others, on the other hand, would
not be known to be those of immaturity, unless an adult skeleton were there for
purposes of comparison. Sir James Hector uses, for example, the features of the
sternum in his description of the distinguishing characteristics of the genus. It
certainly bears no obvious signs of immaturity; but at the same time its entirely
different shape from the sternum of the large individual shows that this part of the
skeleton does undergo some changes during the process of its complete ossification,
unless, indeed, it be the case that the two individuals in the Natural History Museum
are really of different species; but this conclusion hardly seems likely in view of the

* London, John Murray, 1900.

OSTEOLOGY OF THE PIGMY WHALE. il

many close agreements which they present. The shortness of the neural spines of the
vertebre—although clearly partly at least due to youth, as is evidenced by the rough
edges which they show, indicating the existence of some unossified cartilage—might
not be regarded as entirely uncharacteristic of the species were it not for the second
specimen. Length of neural spines is sometimes a character of importance in the
Cetacea. In the larger specimen the great length of the neural spines is a very
distinguishing feature of the skeleton, and is no doubt a character of the genus or species.
The slightly different form of the scapula in the two whales is another point to which
attention might be directed as evidence of specific difference ; but it hardly, to my
mind, amounts to a sufficiently marked variation, and might also be—probably is—due
to different stages of ossificaticn.

I now proceed to a description of the skeleton of Neobalena, which is mainly

drawn from the larger individual at South Kensington.

The Vertebral Column.

The total number of vertebrae possessed by the larger of the two specimens is 43,

which are thus distributed among the several regions :—
Coicw 2D iSie lb 2 wCanelO—— 43.

The cervical vertebre (Pl. LX. fig. 5), as in Balena, form a fused mass, and the
fusion is very thorough though not absolutely complete. ‘The spinous processes of all
seven are completely fused. A single broad plate of bone, rounded anteriorly and
concave posteriorly, represents the seven spinous processes of the cervical vertebre.
Laterally, however, the fusion is not so thorough. ‘The first five are quite
consolidated ; but behind this mass the backwardly projecting process which corre-
sponds to the metapophysis of the dorsal vertebrae is quite obvious for the two
remaining vertebre of the series. ‘The upper bars of the transverse processes of these
vertebree are longest in the atlas; from this vertebra they gradually decrease in size
up to the fourth. The process in question of this vertebra is pretty nearly of the same
length as are those of the following ones. ‘The lower transverse processes of the vertebree
are fused into a thick plate which is concave on its upper face, that turned towards the
upper transverse processes. It is one solid piece, and no traces exist of its formation
out of various component parts. The anterior end of the plate of bone projects more
than the middle and hinder portions; there is thus a correspondence with the upper
transverse processes. ‘The total length of the seven cervical vertebre is about equal
(a little less than) the length of the succeeding three dorsals.

The dorsal vertebre, as already mentioned, are eighteen in number. ‘The first of
the series (the lower vertebra in Pl. VIII. fig. 2) is much less than those which follow ;
its transverse processes only reach out to very nearly the same level as those of the
immediately preceding cervicals. The transverse processes of this and of the three
following dorsals are thickish from above downwards and not wide; the thickness

92 MR. F. E. BEDDARD ON THE

of these processes diminishes in the succeeding vertebree, and culminates with number
nine of the series, which is thin and lath-like ; in all the following dorsals the thin and
wide character of the transverse processes exists ; these processes go on without much
change, through the lumbars and caudals, becoming, however, much shorter as the
end of the series is approached. ‘The last traces of transverse processes are evident on
the fourth caudal, afler which there are no recognizable projections.

‘The spines of the dorsal vertebre rise up to the sixth (Pl. VII. D. 6); this vertebra
is the first to show a backward inclination of the spine ; the slope of the processes
increases up to the sixteenth, after which they continue to slope at much the same
angle. The length of the spines begins to diminish after the fourteenth dorsal. On
this vertebra the length of the spinous process is 12 inches. They are recognizable
until the beginning of the caudal series (Pl. VIII. fig. 3). On the second caudal
vertebra the anapophyses are on a level with the spinous process, which is still perfectly
separate from them. On the sixth caudal vertebra the spine and the anapophyses form
a low oval elevation of which the component parts are no longer distinguishable. ‘The
neural canal also is persistent up to this point as a canal. On the seventh caudal this
canal has become a groove upon the dorsal surface of the vertebra. There is no groove
or canal from this point till the end of the body. The metapophyses bearing the quite
rudimentary posterior zygapophyses are but little pronounced. ‘They appear to end
with the fourth dorsal vertebra. They do not embrace the anterior zygapophyses but
are set above them. ‘The anapophyses bearing the anterior zygapophyses begin faintly
with the first dorsal. They are recognizable, as already said, up to the sixth caudal,
but they do not grasp the spinous process of the vertebra in front after the first lumbar.
The articulation, however, between these processes and the preceding vertebra is
always very faint. Reckoning the first vertebra which bears chevron-bones as the first
caudal, the skeleton will have only two lumbar vertebra, the smallest number known
in any whale. There are 6 chevrons (Pl. VII.), of which the last only is divided into
two pieces, not ankylosed together.

‘The transverse processes of the dorsal vertebra arise at first from the sides of the
neural arch; later they spring from the centrum of each vertebra. The sixth dorsal
vertebra is the first of the series of those whose transverse process is most unmistakably
a process of the centrum. ‘The vertebra in front of this is nearly, but not quite, in the
same condition; there is still a trace of the origin from the neural arch discernible.
In front of this vertebra the transverse processes are quite distinctly processes of the
neural arch.

The vertebral column of this whale shows a certain number of intermediate
characters. The shortness of the vertebral column, 7. e. the comparative fewness of its
component vertebre, is apparently a peculiarity of this genus. But it throws no
particular light upon its affinities. It is apparently to some extent a question of size;
at least this may be the case, for in the small Balwnoptera rostrata there are as few as

OSTEOLOGY OF THE PIGMY WHALE. 93

50, 48, or even possibly 46. The large species, B. musculus, on the other haud, has
as many as 62 vertebrae in its skeleton. In the Right Whales the figures given by
van Beneden and Gervais are 53-58. Thus Neobalena has the shortest vertebral
column of the three genera considered. The shortness, it will be observed, is chiefly
in the lumbar region, which, consisting as it does of at most 2 vertebree, is the shortest
lumbar region, not merely of any Whalebone Whale, but of any whale at all. Inia,
with 3 of these vertebra, only just betters it. The 15 dorsals, again, are in excess of
any other of the allied whales.

The cervical mass is completely fused, as in the Right Whales. So far Veodalena is
distinctly referable to this division, end differs from the Rorquals. The fusion of the
vertebra appears to go on during life, becoming more complete, as is shown by the two
skeletons dealt with here ; the details need not be recapitulated. ‘The fusion seems to
be more thorough than in Balena. At any rate, the skeleton of an adult Balena
figured by van Beneden and Gervais, which shows no epiphyses in the vertebral column,
exhibits distinctly the lines of separation of all the cervicals from top to bottom of the
neural arch. ‘The same may be said of the cervical mass of an adult Greenland Whale
figured by the same authors. In this skeleton, however, the epiphyses of the vertebre
have not entirely become coalesced. Another distinguishing character of this whale
appears to be the great wing-like masses formed by the lower transverse processes.
In short, it will be apparent from the illustrations that in this region of the vertebral
column Neobalena carries to an excess the characteristics of Balwna.

It must be noted, however, that though on the whole the cervical mass of Veobalena
most resembles that of the Right Whales, there is one feature in which it disagrees
with the characteristics of those vertebra in the genus Balena and comes rather nearer
to the Rorquals. In Salaena the lower transverse processes of the cervical mass are
often reduced, and the second and following ones are much feebler than the first or the
first two. In the Rorquals, on the other hand, the equally strong development of the
lower transverse processes of these vertebrz is a distinctive mark. ‘They are well
developed and equally so in all of them; but the processes, like the vertebre them-
selves, preserve their independence. It is perhaps permissible to call attention to this
as a point of affinity between Neobalena and Balenoptera, though on the whole the
differences between the cervical region in Neobalena and in other Rorquals are more
striking than the likenesses.

The most remarkable feature about the dorsal series of vertebre is of course the fact
that the first dorsal appears to have no rib. Its transverse process does not stand out
as far as those of the succeeding vertebre ; there is thus hardly room for a rib except
a very minute one, which might conceivably have got lost. It is to be remembered,
however, that in both skeletons this rib is wanting, and indeed the next one also
in the immature skeleton. Furthermore, the first actual rib (the second of a hypo-
thetical series) articulates with the sternum, as is always the case with the first vertebra

94 MR. F. E. BEDDARD ON THE

in these animals. Nor is there apparently any room on that bone for the articulation
of a rib lying in front of this. ‘This is a condition quite curiously the reverse of that
which often obtains in Rorquals (and other Cetacea), where the first rib is two-headed
and, indeed, partly double through its extent, being apparently formed by the union
of the ordinary first rib and a cervical rib. In Neobalewna the ribs are decreasing in
number, and in consequence the first dorsal is small. It is, however, in the fully-grown
animal incomplete above, as it is in the immature skeleton, where the neural arches
do not meet. This latter fact is duly noted by Hector.

It has been mentioned that the first six dorsal vertebrz only, and the last of these
hardly, have the transverse processes arising from the neural arch itself. In Balena
the series of vertebre in which the transverse processes arise thus is a longer one.
The first ten dorsals in Balwna australis are provided with transverse processes which
definitely arise from the neural arch; after that point they more and more distinctly
arise from the centrum of the vertebra. The arrangement in JVeobalana is more
like that of Balenoptera. In Balewnoptera laticeps (t= B. sibbaldi) the sixth dorsal
vertebra has a transverse process arising from the centrum. ‘The same appears to be
the case with Balenoptera rostrata.

The Scapula.

The scapula (Pl. VII., Sc.) presents considerable differences of form in the two
specimens. In the younger specimen it is much as was figured by Sir James Hector.
The bone is very elongated and not at all high. ‘The highest point, moreover, is not
the middle of the superior border of the blade. The shape, in fact, is far from regularly
fan-like. A series of measurements showed that the anterior end of the upper border
is the highest part of the scapula. It is slightly depressed in the middle. So very
much does the posterior border slope directly backwards from the glenoid cavity, that
it seems to be almost in a straight line with it and with the acromion. Though I have
seen no scapula in any allied form in which this is the case, it appears that even in
Balena, which has a particularly high scapula, the acromion is actually in the same
straight line, or very nearly so, with the posterior border of the shoulder-blade. Hector
has observed this, but has not emphasized the fact that the acromion and the posterior
border of the scapula are in the same straight line and that there is so far no diver-
gence from the characters of that bone in other Whalebone Whales. As to the elonga-
tion of the shoulder-blade, I found that the measurements of length and extreme
height (not, as already mentioned, in the middle of the bone, but near to the anterior
end, and, moreover, an oblique line ending at the middle of the glenoid cavity) are for
the right-hand bone 123 inches as against 7 inches in height. The left-hand scapula
was a little, a very little, diflerent. The corresponding measurements were 13 and 7.
Taken in the middle of the superior border and drawn at right angles to that border
down to the margin of the glenoid cavity, the diameter of the scapula was not more

OSTEOLOGY OF THE PIGMY WHALE. 95

than 64 inches. The corresponding measurements of some individuals of Balenoptera
were as follows :—

Balenoptera rostrata, 15 x 9.

Balenoptera “ huttoni,” 144 x 83°.

Balenoptera musculus, 504 x 33.

It is clear therefore, from a comparison between these measurements, that the
scapula of Neobalwna marginata is distinctly longer in proportion than it is in
Balenoptera; a fortiori it is much longer in proportion than is the scapula of Balena,
which, as is well known, is a high scapula.

The blade-bone is thin and slightly curved, when viewed from above, in an S-like
direction. It is neither definitely concave nor convex on either side. The com-
paratively wide flat acromion is about three times the width of the coracoid process,
When the scapula is looked at from above, the coracoid is seen to project very strongly
inwards, and the acromion, though but slightly, outwards. The effect of the fore-
shortening is that the scapula seems to end anteriorly in three prongs. In the Rorquals
the same state of affairs is to be noticed; and, as in Balewna australis the coracoid
projects distinctly outwards, we have here another feature in which Neobalena is more
akin to the genus Balenoptera than it is to Balena.

In the larger and more mature specimen the scapula was a little different in form.
It has the more regularly fan-shaped outline of that bone in the Rorquals; but it
has not the appearance of so great an antero-posterior elongation as in the smaller
Neobalena. Measurements confirm this appearance.

The two blade-bones of this individual only differ in the fraction of an inch, 20 and
§ inches was the length as against 11 and $ inches vertical diameter, and 134 oblique.
Thus the proportions in this individual are not so un-Rorqual-like. But at the same time
it will be noted that while in Balenoptera the height is to the length as 1: 13, the same
proportions in the larger Neobalena are as 1: 1}; thus showing that there is really
the same difference here as in the smaller example, though not quite so pronounced.
It may well be that the indented upper margin of the scapula of the smaller specimen
indicates incompleted ossification; it appeared rough to the touch, which is so far
evidence, as bone embedded in cartilage, which will continue to ossify, ends abruptly

in that way.
The Pectoral Limo.

As will be seen from an inspection of Plate VII., the fore-limb of Neobalena is of.
relatively small size. Its proportionate length compared with the length of the body
of the creature is small as compared with that of the Rorquals, and smaller still when

1 T enclose the specific name in inverted commas since the name on the label attached to the specimen is
not certainly correct. I believe it to be B. rostrata.
VOL. XvI.—ParT 11. No. 2.—August, 1901. P

96 MR. F. E. BEDDARD ON THE

compared with that of the Right Whales. It need hardly be pointed out how very
different is this limb from the great paddles of Wegaptera. It is, however, apparently
four-fingered as in the Rorquals; no trace of the additional fifth finger of the Right
Whales was to be observed.

The humerus is short as compared with the radius. The measurements of the
smaller individual were 4 inches for the humerus, and 6 for the radius, The pro-
portions are a little different in the larger specimen.

I append for the purpose of comparison a few corresponding measurements from
other Whalebone Whales :—

Humerus. Radius.

in in.
Balenoptera rostrata ......... 74 103
SCD OTTO = oacinkisbaacadesoede ie 103
13%, GOYDOIED, —.sososeconscoseostonee 15 28
SB ONUS CLLULLS ee ee eee 12 22
LD AITVUS CULU SE eee PEEP Ee 18 31
Balena australis ............... 15 154
EG OPHAPD scocces.08a000000200005¢ 13 od

It seems to be plain, therefore, that the arm of Neobalwna is like Balenoptera in its
proportions; just as the hand resembles that genus in being four-fingered. As the ends
of the digits are evidently missing, it seems to be useless to enter into any description
of the component bones of the hand.

Ribs.

The adult or nearly adult skeleton of this whale possesses 17 pairs of ribs, the largest
known number in any Whalebone Whale: the nearest approach is seen in Balwnoptera
sibbaldi, where there are 16; indeed this latter may possess 17, since the first rib
is occasionally double, a cervical being fused with it. As already mentioned, the ribs
begin with the second dorsal vertebra, the first having apparently no rib. It is remark-
able that in the Cetacea we find precisely what is found in the Manatee and the Sloth—
the decrease of the cervical region by the presence of an additional rib belonging to the
last cervical, and the increase of the cervical region by the apparent dropping of a rib.

As is always the case in the Whalebone Whales, only one rib articulates with the
sternum. This rib (Pl. IX. fig. 6) is very broad below, where it expands into its
articular face; but the broadening is gradual, not sudden ; and it is only the proximal
end of the rib which equals the succeeding ribs in diameter. This broadening is very
marked indeed, and is more marked than in any other Whalebone Whales. The Right
Whales come nearer in this particular to Veobalena than do the Rorquals. The general
form of the ribs undergoes some modification in the series. ‘The first rib is simply

* See footnote to p. 95.

OSTEOLOGY OF THE PIGMY WHALE. 97

curved ; the next four (Pl. IX. figs. 4, 5) are sharply bent at right angles at a point
some distance from the capitulum. The bending in the last of these is not so marked.
It more approaches the regular curve of the succeeding ribs. In the ribs further
towards the end of the series (Pl. IX. fig. 7) the curvature is less and less marked, and
the rudimentary last rib is almost quite flat. At the angle where the rib bends down
it is flat and compressed, as if the bone had been squeezed between the thumb and first
finger. ‘This sharpish edge is recognizable on ribs three to five inclusive, and even to
a trifling extent in number six. The anterior set of ribs are moderately flattened in a
plane at right angles to the long axis of the body.

The last of the series are much more flattened, but in a plane parallel to that axis.
The intermediate ribs have a twist about one fourth of the way down; the distal
portion of the rib gets to be expanded in a plane parallel with the long axis of the
body, while the head end retains its parallelism to axes at right angles to the long
axis of the body. ‘This twist is gradually rectified as we progress from the anterior
to the posterior ribs.

The peculiar form of the first rib has been mentioned. The six following ribs are
narrow in diameter. The eighth has a greatest diameter of 34 inches; the greatest
breadth is attained by the tenth, which is some 54 inches in diameter. This is
maintained through the next four, after which the breadth diminishes and the small
last rib is very narrow, and indeed altogether rudimentary. The very different
appearance of ribs from different regions is illustrated in the accompanying drawings
(Pl. LX. figs. 4-7). None of the ribs reach the bodies of their vertebrae, a feature in
which of course Neobalena agrees with other Mystacoceti. But several of them have
a distinct capitulum and tuberculum with an intervening neck. In the first rib these
could barely be distinguished. Ribs 2—6 have both capitulum and tuberculum quite
plain ; these are most obvious, because separated by a longer neck, in vertebre 3 and
4 (Pl. IX. figs. 4, 5); in them the neck measured about 5 inches in length.

Another feature which the ribs of this whale share with those of other Whalebone
Whales should be noticed. In the posterior and more rudimentary bones of the series
the rib gradually decreases in diameter, not only at the distal free end, but also at
that end which is nearest to the vertebral column. It does not appear, indeed, that
during life the thin commencement of many of the posterior ribs ever came into direct
relations with the vertebral column. It is, in fact, the middle part of the rib which is
alone ossified, the two ends having apparently been represented by fibrous or
cartilaginous tissue.

The great breadth and the large number of the ribs of Neobalwna give a suggestion
of a Sirenian to this, as I believe, primitive form of Whalebone Whale. ‘The likeness.
is here only pointed out; it is not possible to build any views as to the affinities of the
Cetacea upon it.

In the introductory anatomical sketch of their great work on the Osteology of

Pd

98 MR. F. E. BEDDARD ON THE

Whales, MM. van Beneden and Gervais make a statement which the structure of the
present species of whale, as will be seen by a glance at Plate VII., does not bear out,
and perhaps in a more marked degree than some other Whalebone Whales. The
authors remark that in Whales in general, not only in Whalebone Whales—* Les
premiéres (c6tés) sont toujours les plus larges et les plus courtes.” This is most
clearly untrue of Neobalwna marginata, and is really not absolutely true of all other
whales, though unquestionably it is of the great majority.

In a quite unexpected way Neobalena resembles not so much other Balenidee as it
does many Toothed Whales as regards one character of its ribs. In the former group
the ribs are, as has been pointed out by van Beneden and Gervais, less flattened and
distinctly more rounded than they are in the Odontocetes. This flattening is carried
to an enormous degree in Neobalena, which thus departs very widely from its nearest
allies among whales. That there happens to be in this particular a resemblance to
that group of whales with which Neobalena has plainly no obvious affinities, cannot
but be regarded as a caprice of structure of no account in considering the affinities of
our whale.

As to other likenesses and differences from other Whalebone Whales which
Neobalena shows in the form of its ribs, the following comparisons seem to be of
perhaps some importance, in addition, of course, to the highly remarkable fact, already
emphasized in connection with the vertebral column, of the commencement of the
series of ribs with the second dorsal vertebra.

In Balena australis the first rib is much curved round at its articulation with the
vertebral column, very much more so than in Neobalena, but it must be said to lack
a ‘“‘neck,” since it is the extremity of the bone which is attached to the vertebra—
“Le col et la téte manquent également du reste aux premicres cétés,” is the statement
of the authors of the ‘ Ostéographie des Cétacés.’ The last five ribs of that whale
are incomplete and possess no neck. ‘There are thus nine which have a clearly
developed capitulum, though of course they do not reach the bodies of the respective
vertebree. In the other species of Balena, B. mysticetus, there are but thirteen pairs
of ribs. Of these the first two pairs have no trace of head or neck. The last
two are similar in so far as this point is concerned. ‘There are therefore here at any
rate nine ribs with a neck. The number is not very different from that of Balena
australis. In Neobalena it is plain that a considerable number of ribs have acquired
the secondary character of possessing both tuberculum and capitulum.

Turning to the Rorquals we find quite a different state of affairs. In Megaptera,
where there are fourteen pairs of ribs, only the third and the fourth agree to differ
from the rest by the possession of a distinct neck. But there are traces of the division
in at any rate the two following ones. In Balenoptera musculus Sir W. H. Flower
described ! the ribs in the following words—* The first rib is simple... The second

‘ P. Z. §. 1864, p. 415.

OSTEOLOGY OF THE PIGMY WHALE. 99

and third have capitular processes which reach nearly to the bodies of the vertebre,
that of the second is rather the longest . . . . The neck becomes rudimentary in the
fourth and obsolete in the fifth and all succeeding ribs.” In “ Physalus latirostris”
(which appears to be identical with what is now known as Balenoptera sibbaldi)
there are fifteen pairs of ribs. But though there is one pair more than in the last
species the ribs are less modified. The second and third, according to Flower, have
well-developed capitular processes; but these processes become “ nearly obsolete” on
the fourth.

The small Balenoptera rostrata has, in correspondence with its diminished size,
fewer ribs than its gigantic allies. It has only eleven pairs of these bones. MM. van
Beneden and Gervais find from an examination of skeletons that, as in other Rorquals,
the first pair are without a capitulum. It is not necessary to go into further details
concerning the characters of the ribs in the Whalebone Whales. I may say that the
facts given above have been verified by me in the skeletons of these whales in London.
The principal generalization to be drawn from these facts is that the genus
Balenoptera has a more imperfect series of ribs than the genus Balena. Fewer
ribs in the former have the two heads of the typical mammalian rib. Now in this
feature it is clear that Neobalena comes nearer to Balenoptera than to Balena. It is,
in fact, somewhat intermediate between the two. We might presume that Neobalena
offers a more primitive state of affairs than either of the remaining families of Right
Whales from certain points of view. It is perfectly clear that the origina] condition
of ribs is shown (so far as concerns the Mammalia) in the Monotremata. In that
group the ribs retain their primitive intercentral position, arising only from the bodies
of the vertebre, and having no connection with the transverse processes of the
vertebrae. It does not, however, follow from this that Balwnoptera and Megaptera
exhibit the least archaic conditions, because there are so few ribs which retain at any
rate traces of the presumably primitive connection of the ribs with the centra of their
vertebre. It seems to me that Prof. Max Weber! has shown conclusively, in
opposition to Prof. Albrecht ?, that we must look upon whales as definitely
“eutherian” mammalia and as not representing in any way the problematical
‘“‘promammalia.’ If that be so, the ribs of whales are derived from those of some
terrestrial mammal in which both central and tubercular heads were present. ‘The
loss of the former and the feeble development of the latter are to be explained by
respiratory exigencies, necessitating an imperfect articulation with the vertebre at
both points.

This allows of course of a greater expansion of the chest-cavity and a consequent
completer filling of the lungs with air. If it could be shown that Neobalena is a

* Weber, “ Ueber die Cetoide Natur der Promammalia,” Anat. Anz. ii.
* Albrecht, “ Ueber die Cetoide Natur der Promammalia,” ibid. i. p. 338.

100 MR. F. E. BEDDARD ON THE

whale which dives more persistently and for greater periods of time than any of its
allies, the large number of ribs and the fact that so many of them are so imperfectly
attached to the vertebral column would be intelligible. But we have no knowledge of
the habits of this whale which could allow of any such a theory.

The Sternwum.

The great care which must be exercised in using the sternum as a character of
generic or specific importance in whales, is illustrated by that of the present species.
Sir James Hector correctly figures the sternum of the individual studied by himself,
and well describes it as ‘ bearing a striking resemblance to a scutcheon.” It has in
fact precisely this form in the smaller and immature skeleton of Meobalena in the
3ritish Museum. The anterior border projects in the middle line, and again on both
sides, while the margins are rounded and converge slightly posteriorly. On the other
hand, as will be seen from the drawing which I exhibit here (Pl. IX. fig. 2), the
sternum of the larger and more mature skeleton is quite different. It has, as will be
seen, somewhat the form of a Maltese cross. The anterior border, the posterior
border, and both sides are excavated at points exactly, or very nearly exactly, opposite
to each other, so that on the whole a cross-like form is produced. The anterior
excavation is the deepest of the four. The two lateral excavations are rather more
pronounced than that of the posterior border. In the figure to which I have just
referred, the sternum is viewed a little in profile owing to the position of the
skeleton and the impossibility of getting a direct dorsal view. But no confusion can
arise in consequence as to the shape of the bone and the proportions of its different
parts. Now it is curious that the sternum which appears to be the more unfinished,
i. e. the least ossified, is that of the demonstrably older individual. The filling in of
the anterior excavation with bone and its projection forward would certainly appear at
first sight to be a mark of age. It may still be the case that the specimens are really
of different species. But other considerations forbid this assumption in my opinion.
The variability of the form of the sternum is only another illustration of the fact that
degenerating organs tend to vary considerably. But the variations of form of this
organ seem to be greater in Veobalena than in any other Whalebone Whale.

The Skull.

As will be seen from an inspection of the large drawing (PI. VII.), which is illustrative
of the entire skeleton of Neobalena, the skull is not large in proportion to the rest of
the skeleton. That drawing, it should be explained, is not exactly parallel to the
horizon. ‘The position of the skeleton in the Whale Gallery at the Museum rendered it
impossible to obtain an accurate horizontal sketch. The amount of obliquity, however,

OSTEOLOGY OF THE PIGMY WHALE. 101

does not seriously interfere with the understanding of the proportions of the different
regions, while it does not at all mask the form of the various parts of the skeleton.
The proportions of the length of the skull to that of the entire skeleton including the
skull are as 1: 54. It will be noticed therefore that the proportions are not those
of either of the whales of the genus Balwna. The proportions, in fact, are roughly
those of any species of the genus Balenoptera. ‘The proportion of the head to the
trunk has formed in the diagnosis of many naturalists an important feature in the
distinguishing of the families Baleenide and Balenopteride, or of the genera Balena
and Balenoptera, according to the views taken of the systematic arrangement of
the Mystacoceti. So far Neobalena is in no sense intermediate; it distinctly resembles
the Rorquals.

But the general aspect of the skull is on the whole suggestive of that of Balena.
This likeness is of course emphasized by the long whalebone, which extends in the
dried skull to a point considerably below the lower margin of the mandible, when that
bone is approximated to the upper jaw. The skull as a whole is arched and the
rostral part is narrow ; this latter feature is well exhibited in the figure (Pl. VIIL. fig. 1)
which illustrates the skull viewed from above. If this aspect of the skull of Neobalena
be compared with the corresponding aspect of the skulls of Balena and Balenoptera,
the closer resemblance of Neobalena to the former genus will be apparent. For in
the Rorquals the rostrum is much broader than in Balewna. The length of the
rostrum also as compared with that of the rest of the skull is a feature in which
Neobalena suggests a true Balena rather than a Rorqual. The rostral portion just
about equals in length the back part of the skull. It is not, however, to all appearance
quite so long proportionally as it is in the Right Whales; but the difference is in
reality due to the narrowness of the frontal bones in Balwna, a feature which seems
to be if anything less marked in Balena australis than in its Greenland congener,
B. mysticetus. It is interesting to note that Meobalwna is nearer to what we must
probably look upon as the less specialized type of Right Whale; less specialized
because of its wider range, variability, less arched skull, &c. It is also permissible to
point out that the proportions of these different regions of the skull and the degree
to which the bones form an arch anteriorly, are more like those of a foetus of Balena
mysticetus figured by MM. van Beneden and Gervais! than the adult of either of the
two Right Whales. It may be further observed that in the young of B. mysticetus
the head is not so enormously large in proportion to the trunk as it is in the adult
of that whale.

Coming to the details of the skull-structure in Neobalena, we find on the whole a
greater likeness to Balena, but that in certain features the characters of the Rorqual
appear.

1 Ostéographie des Cétacés, pl. 1. figs. 7, 8.

102 MR. F. E. BEDDARD ON THE

The vertex of the skull is situated just behind the nasal bones.

The nasal bones are not unlike those of other Mystacoceti in their general form. It
will be observed from the drawing (PI. VIII. fig. 1) that they are distinctly asym-
metrical when seen from above; the right bones are larger than the left. his
drawing, it should be explained, is a copy of the skull of the younger individual.

The mavillw (Pl. VIII. fig. 1, Pl. IX. fig. 1, Mav.) are, as usual in these whales, bones
of a bent form; the posterior half meets the anterior half at an obtuse angle. ‘The
former is much shorter than the latter, the proportions being as 1:2. ‘The actual
lengths, as measured, are respectively 16 and 33 inches. The form of this bone as
regards the proportions of its two halves is like those of the Right Whales and
contrasts with those of the Rorquals. In the latter the descending bar of the maxilla,
though it reaches below the orbit in Balenoptera, as it does in Neobalena, is distinctly
shorter, the anterior portion being thus relatively much longer in that genus of whales.
Another character of this bone shows in Neobalena a close likeness to what obtains in
the genus Balena. ‘There is posteriorly a ridge near to the posterior boundary which
curves round, but is of comparatively slight extent, both in MVeobalena and Balena.
In Balenoptera, on the contrary, we find that this ridge is very much more marked,
and that it extends further, curving backwards in the direction of the occipital region
of the skull, and, as it were, sheltering the frontal bone behind. The maxillz do not
reach the end of the jaw.

The inner angle of each maxilla is prevented by the premaxille from coming into
contact with the nasals; it extends back, as already mentioned, for a little way beyond
the outer portion of the bone, that portion which extends backward being of about
the same diameter as the adjacent premaxillary. In Balwna there is the same failure
of the maxille to articulate with the nasals; but the forwardly running portion of the
bone is hardly differentiated. The Rorquals, on the other hand, show an entirely
different arrangement of these parts. The internal angle of the maxilla is prolonged
into a long and narrow process, which extends for a long way backwards and articulates
directly with the nasals. There is completed in some of these whales a condition
which is only just commencing in the genus Neobalena.

The frontal (Pl. VIII. fig. 1, Pl. LX. fig. 1, Hr.) bone of Neobalena is, on the other
hand, decidedly more like that of Balwnoptera than of Balena. If the skulls of the
two latter genera be compared with each other, it will be noted that they differ
markedly in the width of the frontal bones. In the Rorquals these bones are very
broad, and thus get an appearance of being much shorter than those of Balena, which
are narrow, and, indeed, hardly exceed in width the descending part of the maxilla.
Furthermore, their backward inclination in the Right Whale is much more marked
than in the Rorqual. As will be seen from the drawings exhibited (Pls. VIIL. & IX.
fig. 1), the conditions which are to be met with in this region of the skull of Neobalena
are quite like those of the Rorqual. The descending part of the frontal, where it

OSTEOLOGY OF THE PIGMY WHALE, 105

forms the margin of the orbital cavity, is very broad and short relatively to its length.
It is, in fact, constructed precisely on the same plan as that of the frontal in the genus
Balenoptera.

Viewed from above the orbital portion of the frontal bones is decidedly squarish in
outline. The length of the anterior side, that to which the maxilla is attached, is
pretty nearly the same length as the side which overhangs the actual orbit. The
frontal extends so far back that when the skull is looked at from above there is no gap
to be seen between the frontal and the squamosal. In the skulls of both Balena and
Balenoptera this is not the case ; and they are always, and properly, figured as showing
a large vacant space between the edges of the two bones mentioned. Otherwise the
general outline and indeed the proportions generaily and the mutual angles of the
borders of the frontals of Neobalwna are almost a replica of those of the Rorqual, and
correspondingly distinct from those of Balena. It will be observed from an inspection
of the drawing exhibited (Pl. VIII. fig. 1) that a forward process of the frontal indents
the maxilla, that bone having a corresponding concavity upon its anterior edge which
receives the convexity of the frontal. To the inside of this the maxilla extends
forwards for a short distance until it is stopped by the median part of the frontal bone,
with which it articulates. The convexity thus formed upon the frontal is not,
however, very deep. When we compare these conditions with the corresponding ones
in Balena and Lalenoptera, we find that Neobalwna is somewhat intermediate, with
a stronger resemblance to Balena. In the Rorquals the maxilla extends for a long
way forward, while in balena the edge is nearly straight. Thas Meobalena occupies
a midway position with respect to its two allies; but it is decidedly nearer to Balena
than to Balenoptera.

Lodged between the frontal behind the maxilla in front is the small /acrymal bone
(Pl. IX. fig. 1, Z.), which is thin and plate-like. It presents no features of special
interest when compared with the corresponding bone in Balana and Balenoptera.

The premaaiile (Pl. VIII. fig. 1, P.Wa.) of Neobalena reach right to the end of the
jaw, from a participation in which the maxille are excluded. This is shown both in
the lateral and the dorsal view of the skull. They are thin and narrow bones which
preserve approximately the same diameter throughout their whole course, being only
slightly wider posteriorly than anteriorly. Posterioriy they are widely separated, and
leave a wide vacuity in the middle line of the skull above; for the last one-third
of their total length they are in contact. ‘They articulate behind with the frontals and
with the nasals, and, of course, along the whole length with the maxilla. The articu-
lation with the nasals is for nearly the entire length of those bones, and, as already
mentioned, the premaxille and the frontals are the only bones which have a junction
with the nasals. Where they embrace the nasals they are bowed inwards. ‘The
premaxille of Balena offer a few points of difference from those of Veobalena, but on
the whole agree with them more closely than do those of Balenoptera.

VOL. XVI.—ParT I. No. 3.— August, 1901. Q

104 MR. F. E. BEDDARD ON THE

In the first place, the premaxille of Ralena embrace the whole length of the nasal
bones, and even extend beyond them ; in the second place, they appear to be in contact
anteriorly for rather a greater extent than is the case with Neohbalana. These bones
are altogether more prominent upon a dorsal view of the skull than in Neohalena. In
the Rorquals the premaxilJa are still more different from those of Neohalwna. They
only reach the anterior half of the nasal bones, the maxille, as already stated, arti-
culating with the latter bones. This is not, however, always the case, for van Beneden
and Gervais figure a dorsal view of the skull of Balenoptera sibbaldi in which the
premaxille not only reach the entire length of the nasals, thus cutting them off from
the premaxille, but extend considerably beyond them. On the other hand, in a skull
of B. rostrata the premaxille stop short of the nasals. ‘These differences, possibly due
to the state of ossification of the skulls in question, may therefore be regarded as of
less importance than the fact of the great backward extension of the maxilla, which
occurs in all skulls of Balawnoptera.

The occipital bone of Neobalena is remarkable for its great length, which gives to
the back part of the skull a much greater extent proportionately than in other Whale-
bone Whales. This is clearly seen in the drawing which shows the skull when
viewed from the side (Pl. IX. fig. 1) more clearly than in that (Pl. VIII. fig. 1) which
exhibits the skull from above. The exoccipital regions on either side of the condyles
project much further back along the squamosals than in any Balena or Balenoptera.
Superiorly the occipital is naturally wider behind than in front ; it is ridged along the
middle line and terminates anteriorly in a square face of articulation with the frontals.
The diameter gradually diminishes from the back part of the skull to the anterior end
of the bone. The length of the bone is greater than the width of any part which
appears on the dorsal surface of the skull, as is seen in the figure referred to (Pl. VIII.
fig. 1).

The posterior contour of the occipital is different from that of either Balwna or
Balenoptera. ‘The lateral parts of the bone jut out considerably beyond the level of
the condyles, while in Balewna the posterior transverse line of the skull is nearly
straight, less so, however, in older than in younger specimens. In Balewnoptera we
find the same relative straightness of the posterior face of the skull. The differences
appeared to me, from a comparison of actual skulls, to be rather greater than is
depicted in the figures illustrating the ‘ Ostéographie des Cétacés.’ Viewed from
above the form of the occipital is not uncharacteristic. For in Balena this part of the
bone is as broad as it is long, or nearly so, and of a more rounded form than in
Neobalena. In Balenoptera the bone is also comparatively short and wide, and,
moreover, it does not nearly reach to the anterior end of the orbital plates of the
frontal. In Neobalena it very nearly does so, and in this feature the skull of
Neodulwena is much more distinctly to be compared with that of balena. Indeed

OSTEOLOGY OF THE PIGMY WHALE. 105

the great length of the roofing portion of the occipital bones is a very distinctive
feature of the whale Veobalena as compared with its immediate allies.

The sguamosal (Pl. VIII. fig. 1, Pl. IX. fig. 1, Sg.) is rather characteristic in its
form in this whale. The lower border of the bone projects down behind the glenoid
cavity considerably further than it does in front. In this region, indeed, it hardly
overshadows the condyle of the lower jaw, there being from before backwards a gradual
descent in the margin of the bone. ‘There is, moreover, a much shorter part of the
lower margin of the squamosal lying in front of the condyle of the lower jaw than
there is behind it. On the whole the genus Balena is most like Neobalena in this
particular; in Megaptera and in the Rorquals the bone is much wider across the
elenoid border, and the half of the border which lies in front of the glenoid cavity is
proportionately much longer. This great forwardly directed process of the squamosal
is but feebly developed in Neobalena.

Viewed from above, the disposition of the squamosal differs in the three types of
Whalebone Whales almost equally, and Neobalena is not any more like Balena than
it is like Balenoptera. As already mentioned, the occipital projects back for some way
behind a line passing through the two occipital condyles, and the backward projection
of the sqnamosal is almost exactly coextensive with the hinder parts of the exoccipitals.
This is to a certain degree paralleled in Balenoptera, where the two bones end
posteriorly at about the same level; but in that genus the projection of the two
beyond a line drawn at right angles through the occipital condyles is very much less
than in Weobalena. On the other hand, in Balena the squamosal projects back with
an extension which is quite as fully marked as in Neobalena, but the exoccipitals do
not accompany this backward projection of the squamosal. ‘This statement is at
variance with the numerous figures of the skull of Balwna seen from above, such as
those of Gray in the ‘Catalogue of Seals and Whales,’ or the figures of MM. van
Beneden and Gervais; but all those figures represent the skull viewed in such a fashion
that the occipital condyles are entirely or nearly entirely exposed. My own comparison
represents the skulls of these three whales viewed more directly from above without a
complete exposure of the condyles.

In the arrangement of the pterygoids and the palatines, Neobalena is much like the
Right Whale; in Balwnoptera the pterygoids have a marked backwardly directed
spur; of this there are only traces in Neobalena.

The lower jaw of Neobalena is remarkable on account of its great depth. Its
curvature is sigmoid, and the symphysis is preceded by a decided dip downwards in
the direction of each mandible. ‘The coronoid process is quite feebly marked, but is
still perfectly recognizable (as is to be seen in Pl. IX. fig. 1, C.). When viewed from
above (PI. VIII. fig. 1) the spoon-shaped outline of the interspace between the two
rami of the mandible is seen to be but feebly represented.

Q2

106 MR. F. E. BEDDARD ON THE

‘The space has comparatively straight margins. In these features the jaw of this
whale is distinctly more like that of Rhachianectes than of any other Whalebone
Whale!. Restricting our comparison to the genera Balena and Balenoptera, it is
clear that Neobalena in the characters of the lower jaw comes nearest to Balena.
This it approaches in two marked features: in the first place, it agrees with Balena
in the feeble development of the coronoid process; and in the second place, of the
downward inclination of the symphysial region of the bones. It is, however,
proportionately much deeper than in Balena. This latter statement also applies
to a comparison of it with Balwnoptera. As in other Whalebone Whales, the angle
of the lower jaw does not project back beyond the condyle.

It will be apparent from the above description of the skull of Meobalena that it
most resembles that of Balewna, but that it shows a few points of approximation to the
skull of Balenoptera, and possesses a few others in which it is peculiar and unlike
either genus.

I propose on a future occasion to compare the skull and the skeleton of Neobalena
with that of another aberrant Whalebone Whale, khachianectes. But, in the
meantime, I may point out that the two genera seem to have pursued two different
paths of modification. While Neobalena may be best described, perhaps, as a Right
Whale with a dash of Rorqual about it, Rhachianectes is decidedly a Rorqual with
about an equal mixture of Right Whale.

It may be useful to abstract from the foregoing account of the osteology of Neobalena
marginata the features in which it presents resemblances to the genera Balenoptera
and Balena and to contrast with these the peculiarities which appear to be distinctive
of the genus Neobalena.

Neobalena agrees with Balewna in the following assemblage of characters :—

(1) The arching and the narrowness of the anterior part of the skull.
(2) The absence of a marked coronary process upon the mandible.
(3) The complete fusion of the seven cervical vertebre.

(4) The great length and the characters generally of the whalebone.
(5) The absence of throat-grooves.

Neobalena agrees with the genus Balenoptera in the following larger number
of characters :—

(1) The proportions of the skull to the rest of the skeleton.

(2) The great breadth and the shortness (from above downwards) of the orbital
portion of the frontal bones.

(3) ‘The small number of ribs which possess the capitular head.

(4) The general shape of the scapula.

‘ It should be noted that in the drawing which illustrates the dorsal view of the mandibles (PI. VIII.
fig. 1) those bones are a little displaced, and thus appear to contradict the above statements.

OSTEOLOGY OF THE PIGMY WHALE. 10%

(5) The proportions of the arm to the forearm.
(6) The existence of only four fingers in the manus !.
(7) The presence of a dorsal fin.

The anatomical features in which Neobalena is peculiar and disagrees with both
Right Whales and Rorquals are more numerous still ; they are as follows :—
(1) Small size (cf., however, Balwnoptera rostrata).
(2) The great length of the region of the skull which les behind the orbit.
(3) The depth and the form generally of the mandibles.
(4) The large quadrangular lower transverse processes of the cervical vertebre.
(5) The great shortness of the entire vertebral column.
(6) The extremely reduced lumbar region of the vertebral column.
(7) The large number of the ribs, their breadth and flatness, and the commence-
ment of the series with the second and not the first dorsal vertebra.
(8) The shape of the sternum.

From these facts a definition of the genus may be compiled, and will be the
following :—

Genus NEroBaLa&NA.—Size small, 20 feet or so. Dorsal fin present. No throat-
grooves. Head hardly more than one-fifth of the length of the entire body. Baleen
long. Skull like that of Balena, but with much produced postorbital region and
broader frontals. Mandible deep, with only a rudimentary coronoid process. Cervical
vertebree completely fused, the lower transverse processes forming a strong quad-
rangular mass. Dorsals 18 in number. Lumbars 2. Caudals 16. Ribs very numerous,
17 pairs, the first attached to the second dorsal vertebra ; the posterior ribs broad and
flattened, the first six only with traces of capitulum. Shoulder-girdle elongated
antero-posteriorly, with long coracoid and acromion. Head shorter than radius.
Digits four. Sternum cross-shaped.

P.S., May 1901.—Since this paper was read, Mr. 8. F, Harmer, F.R.S., has kindly
directed my attention to a skeleton of Neobalwna marginata in the Museum at
Cambridge. In this example, which is immature, the epiphyses of the vertebre being
quite separable, the sternum has an outline different from both the two examples with
which I have dealt above. In the Cambridge specimen the outline is roughly that of a
half an oval divided across the longer diameter. The straight edge forms the anterior
border.

There are seventeen ribs on each side, and to the first dorsal vertebra no rib is

1 Lam, of course, aware that Dr. Kiikenthal (‘ Die Walthiere,” in Denkschr. Jen. Ges. 1889) has shown that
in Balenoptera musculus there are a series of cartilaginous pieces intercalated between the third and fourth
fingers, which he considers to represent the missing digit of the adult Rorqual hand. If this be shown to be
a general feature, it will not interfere with the anatomical difference between Balana and Balenoptera in the
manus, though it will, of course, show that the supposed thumb is not the equivalent of that digit.

108 OSTEOLOGY OF THE PIGMY WHALE.

attached.

It is highly improbable, Mr, Harmer informs me, that it ever had a pair
of ribs.

The first five cervical vertebra are completely fused, except, of course, for the nerve-
foramina. ‘The neural arches of the 6th and 7th vertebre are free from the others,
except mid-dorsally and for a short distance on each side of the middle line. ‘The
6th and 7th vertebre are also partly free from each other in their centra. On the

right side of the body there is a similar slit dividing the 5th from the 6th vertebra.
I have to thank Mr. Harmer for this information.

ae

110 OSTEOLOGY OF THE PIGMY WHALE.

EXPLANATION OF THE PLATES.

Je byINd WUE

Skeleton of Neobalena marginata, one-tenth natural size. From an adult specimen
mounted in the Whale Gallery of the Natural History Museum, South Kensington.
Dii., first dorsal vertebra; D. 6, sixth dorsal vertebra; Ce., mass of cervical vertebre ;
Ch.i., first chevron-bone ; Hy., hyoid; Sc., scapula; S¢., sternum.

rte

TaN AY tee
ial é

Tram. vob. Foo. Nol AVL. F¢ VI.

WGntern Brow imp.
WS Berridge del. J Smit 1th.
OSTEOLOGY OF NEOBALASNA MARGINATA-

— Part 1. No. 4 — August, 1901.

112

ro dis

OSTEOLOGY OF THE PIGMY WHALE.

PLATE VIII.

Skull of Neobalena marginata, viewed from above. J’r., frontal bone ;
O., occipital; Ma., maxilla; P.J/a., premaxilla ; Sqg., squamosal.

g. 2, First four dorsal vertebree of the same.
= 9
5S: uv.

First six caudal vertebre of the same: @, the first vertebra; , the second, &c.

W.S.Berridge del. J.Smit lith.

OSE Ol OGYs On;

Tron, Loot. Soe Vol, NVI G6 VI.

Mintern Bros.imp.

NEOBALANA MARGINATA.

ca 7
a
peo A

Oy

114

So Ov HB OD

4

OSTEOLOGY OF THE PIGMY WHALE.

PLATE IX.

. Skull of Meobalena marginata, lateral view. C., coronoid process of mandible ;

Fr., frontal bone; L., lacrymal; Ma., maxilla; 0., occipital; Sq., squamosal.

. Sternum. ‘The figure is drawn a little in profile, as it was impossible to get

an accurate view of this bone from above.
Cervical vertebra.

. Third rib.
. Fourth rib.
. First rib.

. Fifth rib.

Trans. Loot, Soc. Vol XVI. G¢_ LY.

W.S Berridge del. J.Smit hth. Mintern Bros.imp.
OSTEOLOGY OF NEOBALANA MARGINATA.

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Ill. On the Breeding-habits of some West-African Fishes, with an Account of the
External Features in Development of Protopterus annectens, and a Description
of the Larva of Polypterus lapradei. By J. S. Bupeurr, MV A., F.Z.8., Trinity
College, Cambridge.

Received and read December 4, 1900.

| Phares X. & XI. and text-figures 19-23. ]

ConrENts.
Page
Te introduction® Sis i.a)2eve ais chr eh SR Sen Ree eereer the tena 115
II. Results of the Search for Polypterus Eggs .............- 116
III. The Habits and Life-history of Protopterus ............ 119
a. Nesting-habits.

b. Development of the Embryo.
IV. The Nesting-habits of Gymnarchus ..........02.0--000- 126
V. The Nesting-habits of Heterotis niloticus..........00.00% 128
VI. The Nesting-habits of Sarcodaces odoé .......4-..-005- 130
VII. The Nesting-habits of Hyperopisus bebe ........ 002-00 130
WATER Conclusion cieystote scatter ler kere tee dementey as aceseeyorsrchepen shows I3L
EXE sp lanationvotgbhewk atesw aw atelalaireucitsietepeten-nceeney terse Ne rons 132

J.—INTRODUCTION.

THE months of June, July, and August of this year I spent on M‘Carthy Island, in
the river Gambia, hunting for the eggs of Polypterus. But in this paper I have
recorded not only the result of my work in this direction, but also my observations
upon the breeding-habits of the African Lung-fish, Protopterus annectens, of the
Teleosteans Gymnarchus niloticus, Heterotis niloticus, and Sarcodaces odoé, and also
my observations upon the nests of another Teleostean, presumably Hyperopisus bebe.
Towards the expenses of this expedition I received contributions from the Government
Grant, from this Society, and from the Cambridge University Balfour Fund. I should
here like to express my gratefulness for this assistance, which enabled me to undertake
what turned out to be, so far as I was concerned, an intensely interesting collecting
trip. When my results are completed, the expenditure will, I hope, be found to have
been justified.

The Island of M‘Carthy is six miles long and about one mile wide, and is situated
160 miles up the river Gambia. The whole of the island is low-lying, and the greater

VOL. XVI.—ParT 1. No. 5.—August, 1901. S

116 MR. J. S. BUDGETT ON THE

part, in the wet season, is completely under water. On the highest part of the island
is the native town of Ginginberri, and the ruins of the old military settlement
where I lived. ‘The eastern half of the island is partly under cultivation, and here
the natives plant rice on the low land, and kuskus or millet on the high land. The
western half of the island is little cultivated, and here was my hunting-ground.

The whole island is traversed by one main swamp, which has the appearance of
having been at one time an old bed of the river, and which is seldom quite dry, even
in the dry season. Parallel with this he several shallower and more irregular swamps,
all of which become perfectly dry in the dry season. These swamps are separated by
belts of low forest, composed largely of leguminous trees, palms, and fig-trees. The
swamps themselves are mostly choked with papyrus and other swamp-grasses; while
in the middle there is often a little open water covered with several kinds of lovely
water-lilies,

The amount of open water depends largely on the rapidity of the oncoming of
the rains. In the present season there was little open water, as the rains came on
very slowly and gave the grass time to grow abundantly.

As the rainy season advances the swamps become filled with water, the river rises
and soon becomes connected with the swamps by narrow creeks, up which great
numbers of fishes pass to the flooded grasslands to spawn. Conspicuous amongst these
are the two species of Polypterus—P. lapradei Steind. and P. senegalus Cuv.

*

II.—Resvtts oF THE Search FOR Poztyprerus Eaes.

From what I observed in my former expedition of its habits, I concluded that the
eggs of Polypterus might be obtained by one of three methods :—

(1) Hunting the flooded grasslands for the eggs in a state of nature.
(2) Inducing Polypterus to breed in captivity.
(3) Artificially fertilizing the eggs of the female.

The first method was persistently tried without success, especially on the occasion of
spawning females being brought in, when, taking a number of natives to the spot, we
examined every foot of water within a hundred yards of the place where the female
had been caught. Five spawning females were caught, but in no case did I find a
single egg.

For the purpose of the second method I took out to the Gambia with me a large
number of wire hurdles, with which I made four enclosures in the swamp. During
the second half of June about fifty Polypteri were caught in pools by the river-side.
As the rains had scarcely begun, and consequently there was no water as yet on the
land where I had made my enclosures, I temporarily turned my fish into large
floating cages in the river, and fed them regularly on minced meat. A few days after
turning them in, I came one evening to feed them, and found that the two cages

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 117

had been torn to pieces by crocodiles and the fishes had escaped. I then rigged up
some temporary cages in pools by the river-side, into which I turned six pairs of
P. lapradei and fifteen pairs of P. senegalus. By the 30th of July there was sufficient
water jn my swamp-enclosures to turn in the fishes, and there they seemed quite happy,
as the grass was now two feet high and I fed them regularly every night. The
enclosures were each eighteen feet long and six feet wide. As soon asI put the food into
the water at one end of the enclosure the P. senegali came hurrying through the grass
from all parts, and greedily devoured it without the least appearance of shyness.
The P. lapradei, however, were considerably more shy, and continually damaged them-
selves against the wire netting. Thus the Polypteri remained until the 5th of
September, and though I examined every inch of the enclosure every other day, I
found no traces of eggs.

The third method was not tried so frequently as I could have wished, as I could
not obtain anything like the number of Polypteri that I procured in the previous
season. ‘The natives at this time use a kind of basket for catching fishes, which is called
the “wusungu.” ‘This they deftly drop over the fishes as they see them move in the
grasses, and putting their hand into the basket from above, draw forth the captives.
Whereas by this method I obtained an abundant supply of Polypterus last year at
the price of sixpence apiece, this year I raised the price to two shillings apiece and
was yet unable to get any large number of specimens. |

The first spawning female was brought to me on the 5rd of July. It was a Polypterus
senegalus, and, on holding it up by the head, it extruded successively twelve eggs. I
had two males with which I tried to fertilize these eggs. One by one I tried them: first
by placing them on the anal fin and on the vent of the male, then by mixing them with
the fluid obtained from the seminal duct, and lastly by mixing them with fluid
obtained from the minced testis. These eggs were then transferred to muslin stretched
ona frame and placed ina large quantity of river-water. ‘They soon attached themselves
to the muslin, but though I watched them until late into the night, no further change
took place and they one by one decomposed. On cutting open the female I found to
my disappointment that there were no free eggs in the body-cavity, but that they were
all attached to the ovary by their follicles.

The next spawning female was obtained on July 19th, when a fisherman brought me
a female Polypterus lapradei which had two eggs in the oviduct and practically none
in the ovary. ‘There were no free eggs in the body-cavity.

On August the 9th a female P. /apradci was brought which had evidently spawned
some time ago.

On August the 14th a female was brought which had nearly finished spawning.
There were, however, no free eggs in the body-cavity. I tried to force out the eggs
from the ovary, and in this manner several came away fairly easily, and I made every
effort to fertilize them, but again without success.

118 MR. J. S. BUDGETT ON THE

On August the 15th another female Polypterus was brought, which had shed all
its eggs. ;

In each case I took several natives to the spot where the female had been caught
and made a very thorough search for the eggs in the neighbourhood, examining every
blade of grass, but found not a single egg.

On August the 19th a small boy brought me a specimen of Polypterus lapradei only
one inch and a quarter in length; it was a most beautiful object (Pl. XT. fig. 1).
The upper surface is marked with black stripes on a golden ground, a conspicuous
golden stripe runs on each side above the eye, across the spiracle, and along the
dorsal surface of the external gill’. The external gills are at this stage of great size,
reaching halfway to the tail, blood-red, and with a row of branches on either side.
Each branch bears a row of pinnules on either side; the pinnules have the same
structure as those of most Amphibian and Dipnoan external gill-filaments, being merely
a long drawn-out blood-capillary loop. The afferent limb of the loop arises from the
afferent artery of the gill-branch; the efferent limb of the loop joins the efferent
artery of the gill-branch. Similarly the afferent artery of the gill-branch arises from
the afferent artery of the external gill, while the efferent artery of the gill-branch
joins the efferent artery of the external gill. Every alternate gill-branch is much
smaller than the next gill-branch (Pl. XI. fig. 2). Hach of these small gill-branches
bends towards the surface of the body, while the large gill-branches extend parallel
with the body. Thus space is economised, and the result is the same as four rows of
branches on the external gill. Arising immediately behind the spiracle, the external
gills may droop ventralwards posteriorly, and do not seem to be moved much by
muscles, except just to straighten the shaft from the drooping position. ‘The heart and
blood-supply to the external gills can be seen with wonderful distinctness through the
transparent ventral body-wall. The dorsal finlets are not differentiated from the tail,
of which they seem to be only a forward prolongation. ‘They are not distinct from
one another, but form rather a continuous dorsal fin. The body is distinctly more
truncate in the larva than in the adult, the head and tail-region being large. ‘The eye
is also very large in proportion.

The area of pigment ceases abruptly ventralwards in a line running from the tubular
nasal opening under the eye dorsal to the shaft of the pectoral fin, thence to the base
of the anal fin.

The larva was extraordinarily active, and, during the moments when it was at rest,
supported the weight of its body on its pectoral fins, the blade of the fin being turned
forwards and not backwards as is usually the case in the adult. The shape of the
pectoral fin differs considerably from that of the adult. The ventral or postaxial border

‘ The young larva which I have described is about one third of the length of any larval Crossopterygian
which has, up to the present time, been obtained. The anatomy of this specimen I hope to describe ina

future paper.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 119

of the basal lobe is in this young larva much longer than the dorsal or preaxial border ;
while the fin-rays become successively longer in passing from the preaxial to the post-
axial border. It follows that the shape of the fin is triangular, the apex being at the
extremity of the postaxial border (Pl. XI. fig. 1). |

Though the spot where this larva was caught was carefully searched, I did not
succeed in capturing another.

Later on the same day, the 19th of August, I had another female P. /avrade?, which
must have finished laying its eggs some weeks before.

On the 21st of August, in my own fish-trap at the mouth of the small creek which
led from the river to the swamp, I found a female P. /apradei which had finished laying
its eggs, and it looked as though, in this case, it had spawned in the river or else at
the mouth of the creek. 1 am inclined to believe, however, that it had temporarily
returned to the river side of the trap after depositing its eggs in the swamp.

On this same day I had a Polypterus senegalus, still crammed with eggs, but not one
free egg in the body-cavity.

During the last week in August and the first in September, I killed fifteen of my
captive females ; but in no case could I attempt artificial fertilization, as the ova would
not come away from the ovaries, and in more than one case there were signs of
degeneration.

On the 5th of September I left for England, leaving five pairs of P. senegalus in
charge of a native, who was to preserve eggs for me if any should be laid.

Though I have little success in this direction to report, I have thought it well to
put on record the difficulties which I encountered in the search for the eggs of
Polypterus in order that any future investigator who may attempt to obtain develop-
mental material of this fish may in being forewarned be also forearmed.

The main difficulties in obtaining the eggs seem to lie in the fact that
Polypterus probably makes no nest, and certainly lays but few eggs at a time, these
being scattered, probably broadcast, throughout the thick vegetation of the flooded
grass-lands. ‘The eggs are minute, and therefore the chances of finding them in a

state of nature are small in the extreme.

III.—Tue Hapits anp Lire-HISToRY OF PROTOPTERUS.
a. Nesting-habits.

Although the development of Polypterus had been the chief aim and object of my
second journey to the Gambia, I was also very anxious to obtain a series of the eggs and
embryos of Protopterus. When I was on the Gambia the previous year, T had brought
me a number of eggs of Protopterus, but 1 suspected that the way in which the native
told me that they had been laid was quite abnormal or altogether untrue.

I had expected, in wading about the swamps, to come across deep holes in the ground
similar to the nests of Lepidosiren, which 1 had become familiar with when in the

120 MR. J. S. BUDGETT ON THE

Gran Chaco of Paraguay some three years ago with Mr. Graham Kerr. However, I
never found such holes, and was completely at a loss to know where to look for the
nests of Protopterus, the natives being entirely ignorant of any but the most obvious
facts of natural history, and having declared to me that the ‘“‘ Cambona,” as they called
Protopterus, was viviparous.

One day my head fisherman, Sory, came to me in a great state of excitement to say
that he had found the children of the Cambona. It was scorching mid-day in the
height of the rainy season, the temperature 99° in the shade. After crossing one deep
swamp we came to the edge of another swamp, and there, about ten yards from the
water’s edge, on dry ground, was an oval-shaped hole filled with water, and in the water
was a great commotion (text-fig. 19); the surface of the water was being continually
lashed from side to side bythe tail of a Cambona, the head of which was away down
under the ground. On being startled, the Cambona disappeared downwards, and the
fisherman, putting his hand into the hole, drew forth a handful of larval Protopterv.

Text-fig. 19.

Nest of Protopterus.

Having now learned where to look for the nests of Protopterus, in a few days I
found a number of similar nests, but never so far away from the water as the first one,
which was found at the end of a period of drought, very unusual at this time of year. |
I soon found a nest full of newly-laid eggs which must have numbered several
thousands, for from the first day to the day the larve left the nest, twenty days later,
I took fifty per day for preservation without perceptibly diminishing the numbers in
the nest.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 12]

Throughout the period of the larve being in the nest, the male Protopterus
stays with them and guards them jealously, severely biting the incautious intruder.
On one occasion the male was observed to leave the nest and to come out by a small
opening which had hitherto been unnoticed, and wriggle off down to the water. This
exit was always found about two feet from the main opening. Frequently there
was a kind of pathway up to the entrance, where the grasses were bent aside. The
main opening measured four to ten inches in diameter, while the exit rarely measured
more than three inches. The depth of the nest was usually about a foot, and the
shape of the nest was quite irregular. There was never any lining, and the eggs
were laid on bare mud. All the males found in the nests measured about eighteen
inches in length.

b. Development of the Embryo.

The eggs, which measure 3:0-4 mm. in diameter, begin to hatch about the eighth
day, and by the tenth day the larve are all attached by their suckers to the side of the
nest. ‘The main features in development are remarkably like those of Lepidosiren
lately described by Kerr, the larvee being provided with a ventral sucker and four pairs
of plumose external gills, one to each branchial arch. I have figured a few stages of
the external features in development, most of which were drawn on the spot from
life, in order that a comparison may be made with Kerr’s excellent illustrations in the
Phil. Trans. vol. 192, plates 8-12.

As all my specimens were procured from the same nest at twenty-four hours’
interval, I am able to show the advancement made daily. As Kerr’s material was
obtained from a large number of nests, he was unable to say what was the age of each
successive stage figured. ‘Though in one nest were found a few specimens at least half
a day in advancement of the rest, and a few also at least half a day behind the rest,
yet the majority appeared to be at a uniform stage of development. When kept in
shaliow dishes I found that the development was much retarded.

Comparing Pl. X. fig. 1 with the corresponding stage in Lepidosiren (op. cit. plate 8.
fig. Ta, 7s, & 7b), it is noteworthy that the egg is here divided into segments, which are
more distinct from one another, the outer surfaces being rounder and not assuming
the same curvature as the egg-capsule. In this the egg of Protopterus approaches
the conditions of Ceratodus. ‘This is the first stage of my series, so that I am not
able to speak with regard to the appearance of the egg in the earliest stage of
segmentation.

The subsequent down-growth of the epiblast over the invaginating yolk (as shown
in Pl. X. figs. 2, 3, 4, & 5) is remarkably similar to the same process in Lepidosiren
(op. cit. plate 8. figs. 10-14), the invaginating rim remaining a nearly straight line.
This appears to me to be the more frequent method of invagination. Mr. Kerr has
himself, however, pointed out to me that the variations which frequently occur in

122 MR. J. S. BUDGETT ON THE

Protopterus are very interesting. ‘The invaginating rim is often curved, as in fig. 5 7,
rather than straight, as in fig. 3, while later the invaginating rim may become somewhat
V-shaped, recalling a similar appearance in certain Amphibia. ‘The invagination
culminates in a crescentic blastopore. The yolk from the earliest stage onwards in
Protopterus is light green in colour. During segmentation the epiblastic pole of the
egg is pink, and this colour gradually replaces the green colour of the yolk, becoming,
however, paler as invagination proceeds. In the later stages, where the tissues are
becoming more transparent, the green-coloured yolk is again seen.

As in Lepidosiren, the medullary groove arises far forwards and grows back to the
blastopore. In Protopterus (Pl. X. fig. 6) the medullary folds, though wider in proportion
to the surface of the egg than in Lepidosiren (op. cit. figs. 17h & 18h), are not quite so
definite, but undoubtedly do encircle the blastopore in the same way just before they
close. From an external examination the blastopore seems to remain more widely
open after closure of the medullary folds than in Lepidosiren.

Pl. X. figs. 7 & 8, corresponding with Lepidosiren (op. cit. figs. 21, 22, & 23), show
a very similar origin of the brain, optic outgrowths, branchial and pronephric eminences,
but the pair of folds which will subsequently give rise to the mandibular and hyoidean
visceral arches is much more marked in Protopterus (Pl. X. fig. 7, I.H.). The
pronephric ducts have also an origin identical with Lepidosiren (op. cit. figs. 21 m,
22m, 23m). In Pl. X. fig. 8, which corresponds very nearly otherwise in development
with Lepidosiren (op. cit. fig. 237), the whole embryo is not so flattened on the yolk,
the head and tail-fold being much more conspicuous. At this stage is seen the first
appearance of the crescent-shaped sucker (Pl. X. fig. 8, ¢.0.) first shown in Lepidosiren
(op. cit. fig. 24).

In Lepidosiren the branchial arches arise on either side, first as one eminence (op. cit.
fig. 22), later three eminences (fig. 23); the last of these then splits into two, and
thus the four arches are formed. In Protopterus they arise first as one eminence
(Pl. X. fig. 7, br.) ; later two eminences (PI. X. fig. 8, dr. 1. & m., dr. m1. & 1v.), these
then each split into two! (Pl. X. fig. 9, 7. 1. 11. m1. Iv.), thus giving rise to the four
branchial arches.

In Protopterus (Pl. X. fig. 9, W.H.), anterior to the four branchial arches, there may
be seen an indication of the mandibular and hyoidean arches, which in Lep/dosiren
(op. cit. fig. 24) are represented by a single eminence.

Protopterus hatches about the stage of Pl. X. fig. 10, often a little later, in some
cases as late as Pl. X. fig. 11. Before hatching there appears to be a covering of cilia,
for particles in the fluid within the egg-capsule stream down the sides of the embryo
towards the tail end. At hatching the four pairs of external gills are a good deal in
advance of the gills of Lepidosiren, the developing pinne being clearly seen. ‘The rate
and direction of growth of the first pair of external gills is very different to that of

1 The cleavage of the hindermost eminence to form the 3rd and 4th branchial arches occurs somewhat
later than that of the foremost eminence.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 125

the succeeding pairs as shown in Pl. X. figs. 10 & 11, Ey.1. Here also may be Seen,
through the dorsai wall, the auditory cavities and the now large fourth ventricle.

Just before the stage of Pl. X. fig. 12 is reached, pigment begins to appear first
in the retina, then on the surface of the head. The fin-folds of the tail now begin to
grow rapidly, and attain a much greater size than in Lepidosiren (op. cit. figs. 31, 32, & 33),
A copious network of blood-vessels spreads over the yolk. The sucker is fully functional,
and the larve hang vertically from the sides of the nest or vessel in which they may
be confined. Although in Lepidosiren this organ is more conspicuous, yet the larvee
appear only to use it for clinging to the uppermost layer of débris in the nest, and so
prevent their falling downwards and getting smothered !.

A striking feature of Protopterus at this stage, compared with Lepidosiren (op. cit.
figs. 81, 32), is the serial arrangement of the external gills, their roots being distinct
from oue another, and placed in a line along the dorsal surface of the deepest part of
the yolk. Anterior to the first branchial cleft there is a faint indication of a spiracular
cleft between the mandibular and the hyoidean arches (Pl. X. fig. 12, sp.) of which in
Lepidosiren, externally at least, there is no trace.

The roots of the external gills in Protopterus (Pl. X. fig. 15) remain longer separated
from one another than in the Lepidosiren (op. cit. fig. 33). The three posterior pairs also
attain a greater proportionate size. At this stage the tail and dorsal fin-fold are
considerably more developed than in the corresponding stage of Lepidosiren.

As the external gills are reaching their maximum development, the origin of the
gills become somewhat concentrated and rotate forwards, the hindermost gill becoming
dorsal, the anterior becoming ventral.

For some days before leaving the nest, when the young larve are hanging suspended
vertically from its walls by their suckers, the external gills are held stiffly out at right
angles to the axis of the body, forming a radiating frill around the base of the head.
When the larva is lying in a small trough of water, the gills are not thus erected, and
as the drawing (Pl. X. fig. 15) was taken from a living specimen, the gills are shown
lying back along the sides of the body.

The pectoral and pelvic limbs develop synchronously as in Lepidosiren, and are just
beginning to bud in Pl. X. fig. 12, 4.7. Correlated with the extension backwards of the
roots of the external gills, the position of the bud of the pectoral fin is also far back,
and lying immediately below the last external gill, is hidden by them. In PI. X.
fig. 13 the pectoral limbs are of about the same size as the shafts of the external gills.
In one case a specimen had not developed the pinne of one external gill. This bare
shaft so much resembled the pectoral limb, that the larva appeared to have two pectoral
limbs on one side.

In PI. X. fig. 15 the operculum is growing back, the mouth is open, and the internal
gills functional. The larve do not breathe air before leaving the nest. There is now a
considerable development of pigment, especially in the anterior dorsal part of the

: * Kerr, loc. cit. p. 316.
VOL. XVI.—ParT I. No. 6.—August, 1901. T

124 MR. J. 8. BUDGETT ON THE

body. ‘The fin-rays are just making their appearance in the fin-folds of the tail. The
sucker or cement-organ is at its maximum dévelopment. ‘The tail is absolutely diphy-
cercal from the first. Blood-vessels running in the track of the spiral valve shine
through the body-wall (Pl. X. fig. 12, s.v.g.). The spiral valve is first indicated in fig. 12.
The yolk remains chiefly massed in the original position close behind the sucker, and
is not distributed along the gut to the same extent as in Lepidosiren (op. cit. figs. 33,
34, & 35). Wherever yolk is seen, it is of the original greenish colour.

The young Protopterus leaves the nest with practically the form of the adult
(Pl. XI. fig. 3). The mass of food-yolk is not entirely absorbed as yet. The first pair
of external gills has been lost, and the succeeding pairs have been much reduced in
size. The tail ends ina very fine filament. The markings of the young Protopterus
at this time are somewhat different from the adult. The general colour is dark brown,
a conspicuous broad yellow band passing between the eyes. As with Lepidosiren so
with Protopterus, the larve at this stage contract their black chromatophores at
night and become blood-red, the eye shining out deep black in contrast.

It is here interesting to notice that the larval Protopteri, after leaving the nest when
kept in an aquarium the bottom of which was covered with seedling water-lilies,
chara, &c., never show themselves by day, and if disturbed from their seclusion, hastily
make their way back to their hiding-place. After dark, however, by the aid of a
lantern, the larvee may be seen swimming around in the most lively manner, but they
do not come to the surface for air.

It seems, then, that the habit of expanding the chromatophores by day is of advantage
to the larval Protopterus, making it almost invisible while lying passively on the dark
soil, ‘The chromatophores become contracted by night, not by reason of the darkness,
but because this is the period of activity with the larve, and when swimming about
they are certainly less conspicuous when transparent than when opaque, even at night.

Were it customary for the larval Protopterus to swim about in the daytime, they
would probably then contract their chromatophores, becoming less visible with
increased transparency. As a matter of fact, when in the daylight the larve were
placed in a white porcelain dish, in a large number of cases they did contract
their chromatophores. ‘That this contraction on a light background did not always
take place may possibly be accounted for by supposing that continued habit has
produced a certain periodicity in the contraction and expansion of the chromatophores.

While on the Gambia, I kept a large number of young fry of about fifteen species of
fishes, and I noticed that the nocturnal forms did become more transparent at night. The
converse was naturally not noticed, since | know of no fishes which are only active in
the daytime. With frogs, the case is quite different, for they are not aquatic, and would
not therefore be made less conspicuous by being transparent. ‘The chromatophores
are often contracted by them in the daytime when exposed to strong sunlight, for the
objects around them then become of brighter and lighter colour '.

1 “ Notes on the Batrachians of the Paraguayan Chaco,” Q. J. M. 8. 1899, pp. 314, 327, 328.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 125

Soon after leaving the nest, the larve begin to feed on almost any animal matter
they can get. For this reason, though I started homewards with a number of larvee
taken from the nest, only one reached England alive, having eaten all the others. On
the voyage home, the young Protopterus began to move about in the daytime, ceased
becoming transparent at night, lost the external gills, all but small vestiges, and began
to come to the surface for air. This was about one month after leaving the nest, or
about seven weeks after being laid. On reaching England it had quite the form of the
adult.

In comparing the development of Protopterus with that of Lepidosiren, a very
noticeable circumstance is the impossibility of comparing together a larva of each
form as being exactly at the same stage of development. The various organs and
features do not make their appearance in quite the same proportionate periods of time
in the two forms; so that at any one stage, some set of organs in the one will not
correspond in its state of development with the same set in the other.

Many of the differences noted in the external development of the two forms may,
I think, be correlated with the presence in Lepidosiren of rather more food-yolk.
The main differences are :—

A more complete separation in Protopterus of the cleavage-products.
The greater size of the medullary folds.

A more distinct remnant of the blastopore.

The earlier appearance of the cement-organ.

. The earlier rising-up of the embryo off the yolk.

The appearance of two visceral folds in front of the four branchial folds.
A rudiment of a cleft between them.

. The greater size of the gills at hatching.

. The more complete separation of the external gills.

moo Lo

omnA oO Cc

pe
=

The rotation forwards of the external gills.
11. The concentration of the yolk forwards.

I have not thought it well to make any observations upon the bearings of the facts
here described, since it is first necessary to know more of the development than can be
learnt from a superficial examination. Mr. Graham Kerr has undertaken to further
study the development of Protopterus and to incorporate the results in his work on the
development of Lepidosiren. Ihave here described the external features in development
together with what I observed of the nesting-habits of Protopterus, as it would be
difficult to treat either separately.

Comparing the nesting-habits of Protopterus with those of Lepidosiren, perhaps the
most striking difference is the development by the male Lepidosiren in the breeding-
season of the extraordinary vascular fringes of the pelvic fins, recently described by
Kerr. Nothing of the kind is developed by Protopterus. Now, looking to the solution

T2

126 MR. J. S. BUDGETT ON THE

of the problem as to what is the function of these fringes in Lepidosiren, it is natural
to look to see in what the habits of the latter differ from those of Protopterus.

The most striking difference is surely that, whereas Lepidosiren makes its nest
several feet below the surface of the water, Protopterus makes its nest practically out
of the water. I regard the habit of Protopterus of lashing the surface of the water
at the entrance to its nest as a means of aerating the eggs in the nest. Now, it is
tempting to regard the vascular fringes on the pelvic limbs of Lepidosiren as in some
way connected with the aeration of the eggs, for it is obviously unable to make use of
this method of aeration adopted by Protopterus. But the conditions under which this
habit was observed in Protopterus were, as I have said, somewhat unusual, in that,
owing to prolonged drought, the water in the nest was unconnected with the surround-
ing water. When this was not the case, the lashing of the tail on the surface of the
water was not observed. ‘Therefore I do not think this habit can be said to be quite
characteristic of Protopterus. The entrances to the nests, however, were always only
a few inches at most below the surface of the water, while with Lepidosiren the nests
are made in deep water, and it seems more probable that the fringes on the pelvic
limbs of Lepidostren are, as Kerr holds, accessory organs of respiration avoiding the
necessity of frequent absence from the nest in order to visit the surface for air, and
thus perhaps risking loss of the entrance to the nest or the attacks of enemies.
Protopterus, by reason of the shallowness of the water about the entrance to the
nest, would not run these risks in seeking air, and therefore has no need of the
accessory breathing-apparatus.

IV.—THE NESTING-HABITS OF GYMNARCHUS.

While hunting for Polypterus eggs, 1 met with several large floating nests measuring
in all two feet in length and one in breadth. The nests were made in the dense
grasses of the swamp in three to four feet of water (text-fig. 20). The inside measurement
was about a foot by six inches. ‘Three sides of the nest projected from the water; the
fourth side was several inches lower, being about two inches below surface. The
deepest part of the nest was opposite to that side where the wall was low, the bottom
being about six inches below the surface of the water.

In this nest were deposited about a thousand large spherical amber-like eggs 10 mm.
in diameter. The eggs hatched five days after being laid, and in eighteen days a
thousand young fry of Gymnarchus niloticus left the nest when three inches long.
This fish is called by the natives the ‘“ Suyo.”

Though there are many interesting features in the development of these eggs, I do
not intend to deal with them in detail here, but merely to mention that the develop-
ment is exceedingly shark-like. ‘The larve soon after hatching develop extremely
long gill-filaments, which hang down in two blood-red branches from the gill-arches, of
which there are four. ‘The yolk-sac, at first spherical, later becomes drawn out into a

¢y “2 ¥

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 127

long cylindrical bag, attached somewhat far behind for a Teleostean, and covered with
a vascular network (Pl. XI. figs. 4 & 5).

The tail is from first to last perfectly diphycercal, and is at first provided with
a dorsal and a ventral fin-fold reaching right to the tip of the tail.

Before leaving the nest, both outer gill-filaments and yolk-sac are absorbed and the
mature form is reached.

Immediately after hatching, the larve commence their characteristic movements,
throwing the head and fore part of the body from side to side incessantly. The larvee
are at first so small in proportion to the size of the yolk-sac, that they are quite unable
to move it. By this constant movement the larve tend towards the surface, and the

Text-fig. 20.

Ai Mf VSS IVA PS?

Floating nest of Gymnarchus.

weight of the yolk tending downwards, the yolk-sac becomes gradually drawn out into
the long appendage already mentioned. About three days after hatching, the larve are
strong enough by their movements to raise the yolk-sac off the bottom of the nest for a
moment, but it is quickly drawn back by its weight.

By the tenth day after batching, the larve are able to drag their yolk-sac to the
surface of the water, when they take a gulp of air into their lung-like swim-bladder
and fall again to the bottom, on reaching which they again start for the surface with
unceasing regularity, so that when looked at from above the nest of Gymnarchus,
with its swarm of scarlet-bearded, yolk-hampered larvee, presents a most amazing
spectacle.

By the time the huge yolk-sac has been completely absorbed, the young larve are
ready to leave the nest. They still, however, continue their ceaseless journeyings to
the surface for air. It may now be noticed, however, that the passage back to the
bottom of the nest is not merely a passive falling, but that the young larve actually

128 MR. J. Ss. BUDGETT ON THE

dart backwards from the surface. When the young Gymnarchus leaves the nest it has
fully developed the characteristic cylindrical tail of the adult, and in this connection
its habits are very interesting.

The Gymnarchus propels itself through the water, not by the action of its paired fins,
not by the motion of its tail or the undulatory motion of the axis of its body, but
entirely by the action of its dorsal fin. This fin extends nearly the whole length of the
dorsal surface, ceasing abruptly at the commencement of the cylindrical tail. When
Gymnarchus starts forwards, the motion is the result of a series of waves passing
backwards along the dorsal fin. About five such waves are passing at a time.
Suddenly the fish will proceed at the same rate in the opposite direction, and now the
motion is the result of a series of waves passing forwards along the dorsal fin.

As the Gymnarchus swims rapidly backwards in this way, it may be seen to guide
itself through the grasses by using this peculiar tail which it possesses as a feeler.
Thus it appears to be quite immaterial to the fish which way it progresses, and it
always appears to swim in comparatively straight lines.

How Gymnarchus constructs the wonderful floating nest in which it lays its eggs I
have been unable to observe. ‘The natives approach these nests with great caution,
stating that the parent is at this time extremely fierce and has a very formidable bite.
Both the adult fish and its eggs are greatly sought after as food.

A large number of the young fry of Gymnarchus, which I had caught immediately
they left the nest, lived well on chopped-up worms. TI tried to bring some of them to
England alive, but every one died as we got into colder climes.

V.—Tne Nestine-uasits or Hereroris nrtoricus Cuv.

In the same swamps, during the month of July, a most striking feature is the
presence of numbers of enormous nests, which proved to be those of Heterotis niloticus
(text-fig. 21). These nests measured four feet in diameter, and were made in about two
feet of water. In wading through the reed-choked swamp, when one came across one
of these structures they appeared like miniature lagoons. The walls of the nest were
about eight inches thick at the top and compact, being made of the stems of the
grasses removed by the fish from the centre of the nest. The floor of the nest was
the swamp-bottom, and was made perfectly smooth and bare.

Once I watched a “ Fantang,” as the natives call this fish, making its nest. It was
circling round and round the wall of its nest, every now and then throwing its tail
upwards and outwards, tossing on to the top of the wall the débris from the inside of
the nest. Thus it toiled on until the wall reached the surface of the water and was
complete. When the nest was finished, the water it contained was perfectly clean and
clear, so that I could see with my water-telescope the eggs nearly covering the bottom
of the nest. When all the eggs are laid, the fish leaves the nest by a hole at one side.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. 129

The eggs, which measure 24 mm., then appear to hatch in about two days, though,
owing to the distance the nests were from my quarters, of this I am not certain. The
nest appears to be used for at most four or fivedays. As soon as the larvee are hatched,
they begin to strike up from the bottom. ‘he day after hatching they may be seen
continually passing up and down, and are now provided with long external gill-
filaments of a blood-red colour, but not so numerous or so long as in the case of
Gymnarchus (Pl. XI. fig. 6 & 7).

The following day they cease to pass wp and down, and converging to a swarm about
one foot in diameter, form a deep continuous circle remarkable for its regularity and

Text-fig. 21.

Nest of Heterotis.

persistence. ‘The swarm occupies the exact centre of the little lagoon. The young fry,
which by now have lost the long external gill-filaments, are seen to be steadily
careering round and round ever in the same direction for at least a day. About the
fourth day the swarm becomes less persistent and regular, the larvee swimming first to
one side of the nest and then to the other, until about the fifth day they leave the nest
by the exit for a few trial trips attended by the parent, and finally leave it altogether,
swimming hither and thither in a dense swarm, from which the parent is never far
distant. I kept a large number of the young fry for several weeks, but could not get

them to feed, and eventually they all died.

130 MR. J. S. BUDGETT ON THE

The ova of //eterotis are shed into the ceelom as in the Salmon. J//eferotis belongs
to the group Osteoglosside, which has much the same distribution as the Dipaoi,
though it seems doubtful whether this points to an antiquity of the group equal to that
of the Dipnoi. Giinther, however, regards the Osteoglossidee as one of the earliest
types of Teleostean fishes.

VI.—Tue Nestine-Hasits or Sarcopaces ovoii Bl.

In these same flooded grass-lands the eye is frequently caught by masses of whi t
foam floating on the surface of the water. On close inspection it is seen to be filled
with numerous transparent ova, about the same size as those of Heterotis (24 mm.).
Soon these eggs hatch, and on hatching make their way through the foam, in which
they are laid, down to the surface of the water, and there the young larve hang
holding to the surface of the water by a large adhesive organ situated on the front of
the head (PI. XI. fig. 8 & 9, c.0.).

The natives assured me that these were the eggs of the Sannko, more scientifically
Sarcodaces odoé. On rearing some of these larve, I was able to confirm this statement.

Sarcodaces is one of the Characinide, of which family examples occur in Africa and
South America. ;

Vil.—Tue Nesrine-nasits or Hyprropisus BeBe Lacép.
It was a curious fact that of the six species of Mormyridw which I obtained in
the Gambia, only one besides Gymnarchus was found breeding in the swamps. ‘This
was Hyperopisus bebe Lacép.

Eggs from nest, supposed to be that of Hyperopisus bebe.

Although I did not succeed in finding fertilized eggs of Hyperonisus this year, 1
obtained a number of females full of ripe eggs. I am practically certain that these
ovarian eggs are identical with the eggs which I studied last year under the impression
that they were the eggs of Polypterus.

BREEDING-HABITS OF SOME WEST-AFRICAN FISHES. Si

These eggs were laid in shallow depressions of the swamp bottom, and attached to
the rootlets of the grasses laid bare by the parent in scooping out the depression for
the reception of the eggs (text-fig. 22, p.150). The eggs are very small, about 1¢ mm.
in diameter, and slightly oval, the long axis being rather over Ize TM; in length.
They are yellowish in colour and semitransparent. The eggs hatch in four days,
and are then provided with four large cement-glands situated on the top of the head,
and two smaller ones on the front of the head (Pl. XI. fig. 10, ¢.0.). Immediately
the larva is hatched it runs the upper part of its head against the rootlets,
and wriggling away again, draws out from the four cement-glands four fine
threads of viscid mucus, which are hardened by contact with the water, and form a
minute rope about the length of the body of the larva. By this the larva hangs
suspended for four or five days until the yolk is absorbed. If the larva is detached
meanwhile, a fresh rope is formed by a fresh secretion of mucus (text-fig. 23).
While hanging thus, each larva continually oscillates the whole length of its body
from side to side. In one nest there are many thousands of these larvae suspended

Text-fig. 23.

Larve, supposed to be those of Hyperopisus bebe, suspended from the rootlets in the nest.

in this way, presenting the appearance of a shaking mass of jelly, for all the larve
oscillate themselves in unison. I was unfortunately unable to rear any of these
larve to a stage old enough to be able to identify them.

VIII.— Conc usion.

I should here state that I had great difficulty in keeping alive any of the fish-
larve that I found for any length of time in any but the natural conditions,
Protopterus, however, excepted. In the case of Gymnarchus a great number of ways
was tried, even floating perforated trays as an attempt to imitate the natural conditions.
I do not so much wonder at my want of success in this as at the successful way
in which the larva are hatched out in nature. J never found a dead larva in any

VOL. XvI.— PART 11. No. 7.—August, 1901. U

132 BREEDING-HABITS OF SOME WEST-AFRICAN FISHES.

nest of Gymnarchus, notwithstanding that the eggs and larvie were lying within six
inches of the surface of the water, quite unprotected from the burning rays of a
tropical sun and the lashing of the tropical rains. ‘The extremes of temperature
taken in the nests were 25°C. and 32°5 C. But supposing the larve to be so con-
stituted that they can withstand the changes of the weather, how is it that large
conspicuous eggs in very conspicuous nests on the surface of the water escape forming
the food of the abundant bird-life of these swamps ?

In the breeding-habits of the last four types I have described, the interesting
fact comes out that the first two and the last two each have, in common, organs in
the larva which are usually regarded as not belonging to the Teleostean division of
fishes. Gymnarchus and Heterotis have each, for a time, enormously elongated gill-
filaments, structures which are so characteristic of Elasmobranch larve. Something
of the kind was noticed in the development of the loach by Gotte!, but I think
this is the only case of such organs in the Teleosteans. Sarcodaces and Hyperopisus
have each well-developed cement-organs on the head. ‘These structures are generally
regarded as characteristic of the Ganoids. It seems, then, that the conditions by which
fishes, which breed in tropical fresh waters, are surrounded is conducive to the
development of very various accessory organs in the larva, both for the purpose of
respiration and also of preserving them from harmful contact with their surroundings,
and that these structures cannot be regarded as having any great morphological
meaning. ‘lhe resemblance of the embryo of Gymnarchus to that of an Elasmobranch
I hope to discuss in a future work on the development of Gymnarchus.

IX.—EXPLANATION OF THE PLATES.

All the figures of Plate X. were originally drawn by myself with the aid of a camera lucida, and
were then copied by Mr. Edwin Wilson.

Figs. 2, 8, 4, 5, 12, & 13 were drawn on the Gambia from living specimens. Figs. 1, 6, 7, 8,
9, 10, & 11 were drawn from formalin specimens.

The magnification is 8 diameters.

The figures in Plate XI. were all drawn by myself except fig. 1, which was from a specimen
preserved in formalin, drawn by Mr. Edwin Wilson under my supervision and coloured from my
notes by myself. Figs. 4, 5, 6, 7, & 8 were drawn from life on the Gambia. Fig. 3 was drawn
from a specimen preserved with corrosive sublimate and acetic acid.

au., auditory sac; dSp., blastopore; &7., branchial eminences ; ér.1. 11. &c., branchial arches ;
c.0., cement-organ ; cl., position of cloaca; ep.e., growing edge of epiblast; Ay. 1. 11. &c., external
gills; ff., dorsal fin-fold; 4./., hind limb; H., hyoid arch; H.r., hyobranchial cleft; invag., line
of invagination; M., mandibular arch; M.H., mandibulo-hyoid fold; m,f., medullary folds ;
0.¢., optic outgrowth from brain ; op., operculum; p.f., pectoral fin ; pn., pronephros ; s.v.g., groove
marking rudiment of spiral valve; sp., groove between mandibular and hyoid arches ; v.1y., fourth
ventricle ; y.k., yolk-cells.

1 « Tntwick. d. Teleostierkeime,” Zool. Anz. No. 3, 1878.

weal

ese:

Sp NAN (ind
WO h A ay J

134 BREEDING-HABITS OF SOME WEST-AFRICAN FISHES.

At

aur

Vie.
Fic.

Fig.

Vic.

big

Fig

Fig.

PLATE X.

the figures of this Plate illustrate the external features in the development of Protopterus

ectens, Ow.

1. Egg on the first day of observation, segmentation somewhat advanced: p. 121.

2. Egg on the morning of the second day, showing commencement of invagination: p. 121.

3. Egg on the evening of the second day, showing a further stage of invagination. Above is
seen a transparent portion indicating the segmentation-cavity: p. 121.

3a. A yariation of the stage shown in fig. 3. The area of the disappearing yolk-cells is
viewed from a somewhat different aspect, in order to show that the line of invagination is
not here straight but curved: p. 12].

4, Egg on the morning of the third day, showing the straight line of invagination and the
gradual disappearance of the large-celled yolk: p. 121.

4a. A variation of the stage shown in fig. 4, showing that the line of invagination is
not always straight: p. 121.

5. Egg on the evening of the third day, showing the last stage of invagination: p. 121.

6. Egg on the morning of the fourth day, showing medullary folds encircling the blasto-
pore: p. 122.

7. Embryo on the evening of the fourth day, showing origin of optic outgrowths, mandibulo-
hyoid fold, branchial eminence, and pronephros: p. 122.

8. Embryo on the fifth day, showing the segmentation of the mandibulo-hyoid fold and
first segmentation of branchial eminence; also the remnant of the blastopore, and the
first appearance of the cement-organ, and the development of the head and tail-folds:
p- 122.

9. Embryo on the sixth day, showing the further segmentation of the branchial eminence
into four: p. 122.

. 10. Embryo on the seventh day, showing the first pairs of external gills strongly differentiated
from the second, third, and fourth pairs. The trunk of the embryo has grown back
from the main mass of yolk, taking much of the yolk with it. The true tail is not yet
formed: p. 122.

_ 11. Larva on the eighth day, just hatched, showing further growth of the external gills, and
the auditory sacs showing through the tissues. The true tail-region has now begun to
grow: p. 122.

_ 12. Larva on the tenth day, showing the serial arrangement of the external gills, the indica-
tion of the spiracular cleft, the first trace of the hind limbs, being now anterior to the
position of the cloaca, and the well-developed aud functional cement-organ. ‘The tail-fins
are now well-developed. Pigment has appeared on the head: p. 128.

13. Larva on the seventeenth day, showing general advancement, the rotation of the external
gill, the operculum, the vessel in the spiral valve groove, and the well-developed limbs:
p. 128.

sai Bh iy

seg. cav.

as VE ORs

———
Ss ~“\

tity A a ae

be

epee.

0.6.

Spans Lol fol KU GPL HK

ete 23)
N
ee Md Ses

j
’ ;
J.S.B.del. E Wilson, Lith Cambridge.
i s DEVELOPMENT OF WEST AFRICAN FISHES. — ;
PROTOPTERUS

PLATE XI.

Vou. XVIL~—ParT U1, No,

136

Biz

Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
IME, “Yo
Fig. 8
Fig. 9
Fig. 10.

I.

BREBDING-HABITS OF SOME WEST-APRICAN FISHES,

PLATE XI.

Larva of Polypterus lapradei Stein., 14 inch in length, magnification about four
diameters, showing the very large external gill of the hyoid arch, situated immediately
behind the spiracle, the blood-supply to the same from the ventral aorta, and the
very large size of the head and tail-region of the body, also the dorsal fin not broken
up into finlets. The larva is drawn in a very characteristic attitude as observed when in
the aquarium. The smallness of the alternate branches of the gill and their different
position is not shown.

. External gill of Polypterus lapradei, showing the difference in size of each gill-branch :

p. 118.

. Larva of Protopterus annectens Ow., a few days after leaving the nest, about one month

old. The larva was killed when its chromatophores were neither fully expanded nor fully
contracted. The first pair of external gills has been lost and metamorphosis is nearly
complete: p. 124.

. Larva of Gymnarchus niloticus Cuv., one week after it was laid, two days after hatching,

showing external gill-filaments, blood-vessel to and from yolk-sac, and the completely
diphycercal tail: p. 127.

. Larva of Gymnarchus, four days later, showing long drawn-out yolk-sac and abundant

external gill-filaments. The fin-folds of the tail are shown, and the first trace of
differentiation of the tail to form the whip-like feeler: p. 127.

. Larva of Heterotis niloticus Cuv., one day after hatching, showing external gill-filaments,

backward extension of the yolk to the cloaca, the pectoral fins, four branchial arches,
developing operculum, and heterocercal rays in the tail: p. 129.

Larva of Heterotis, dorsal aspect, in order to show relations of operculum, gills, and
pectoral fin: p. 129.

Larva of Sarcodaces odoé Bl., just atter hatching, showing the large adhesive organ borne
on the front of the head: p. 130.

. The same, frontal aspect, to show the form of the adhesive organ: p. 130.

Larva of Hyperopisus bebe Lacép., showing the four dorsal and two frontal cement-organs,
the auditory sacs, and prominent gill-folds: p. 131.

Trans. Loo, Soe Vol AU POXT

20. Oa

J.S.B. del. E Milson, Lith, Cambridge.

DEVELOPMENT OF WEST AFRICAN FISHES

1-2. POLYPTERUS. 3. PROTOPTERUS 4-5. GYMNARCHUS. 6-7. HETHROTIS.
8-9. SARCODACEHS. 10. HYPEROPISUS

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CONTENTS.

Il. Contribution towards a Knowledge of the Osteology of the Piginy Whale (Neo-
balena marginata). By Frank E. Bepparo, V.A., F.RS., Prosector and Vice-
Secretary of the Society. (Plates VIL-IX.) . . . .. . . . page 87

Ill. On the Breeding-habits of some West-African Fishes, with an Account of the
External Features in Development of Protopterus annectens, and a Description
of the Larva of Polypterus lapradei. By J. 8. Buncurr, M.A., 2.Z.S., Trinity
College; Cambridge. (Plates Xs Ge TOI) eet ores are sek 0) ts lee

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IV. Third Contribution to the Ichthyology of Lake Tanganyika—Report on the
Collection of Fishes made by Mr. J. B.S. Moore in Lakes Tanganyika and Kivu
during his Second Expedition, 1899-1900. By G. A. Boutenerr, F.R.S., F.Z.S.

Received and read January 15, 1901.

[Puares XII.-XX. ]

In presenting this report on the second collection made in Lake Tanganyika by
Mr. Moore', I may at once state that the expectations held out in the first report,
as to the possible occurrence, in the greater depths of the lake, of forms differing
fundamentally from the typically African freshwater forms, have not been in any way
realized. Although fully equipped for a complete survey of the lake, both on its
shores and in its depths, which we know to extend beyond 500 fathoms, the Tangan-
yika Expedition organized by Professor Ray Lankester has failed to bring home
representatives of any but the few families already known from the lake, and which
occur also in the other basins of Tropical Africa. Its results only further emphasize
the striking fact of the extraordinary multitude and diversity of the Cichlid

1 For an account of the Expedition, ef. Geographical Journal, vol. xvii. 1901, p. 1.

* Since the publication of the first report, in which lists were given of the fishes of the principal lakes of
Central Africa, the ichthyological fauna of Lake Mweru, which, from its vicinity to Tanganyika, is of special
interest, has become known through collections made by Mr. Alfred Sharpe, C.B., and the Lemaire Expedition
(Congo Free State). It enables me to draw up the following list, in which the names of the endemic species
are printed in italic, the general habitat of the others being given in brackets :—

7. Chrysichthys sharp Blgr.

8. Auchenoglanis biscutatus Geoffr. (Nile, Trop.
Africa).

9. Synodontis zambesensis Ptrs. (Zanzibar to

Mormyripm.
1. Gnathonemus stanleyanus Blgr. (Congo).
. Mormyrus longirostris Peters (Nile, Congo,
Zambesi).

bo

a Mozambique, Nyasa).
enaen 10. Synodontis ornatipinnis Blgr. (Congo).
3. Hydrocyon lineatus Blkr, (Senegal to Congo,

Tanganyika, Zambesi).

CicHLIp&.
4, Alestes macrophthalmus Gthr. (Gaboon, Ogowe,
Congo, Tanganyika). 11. Paratilapia macrocephala Blgr.
5. Alestes lemairit Blgr. 12. Paratilapia mocruensis Blgr.
13, Tilapia natalensis M. Web. (Congo, E. & S.E.
SILURIDm. Africa).
6. Schilbe mystus L. (?) (Nile, Calabar, Congo). 14. Tilapia polyacanthus Blgr.

VOL. XVI.—PART 111. No. 1.—Octoder, 1901. Y

138 MR. G. A. BOULENGER ON A COLLECTION

Perciform Fishes, a very natural group the habitat of which extends over the fresh
waters of the whole of Africa, Madagascar, South-western Asia, Southern India and
Ceylon, and Central and South America. They also confirm the no less remarkable
negative feature of the absence of Mormyrids, a family so eminently characteristic of
the Ethiopian fresh waters, occurring as they do in all the rivers of ‘Tropical Africa,
and in all the lakes north and south of Tanganyika. Lastly, they add to the list of
Cyprinids, and bring out the interesting fact of the presence in that lake of a species
of Capoéta, which genus, well represented in Southern Asia, was known in Africa from
a single species inhabiting Abyssinia. But the general conclusions which could be
drawn from the study of the first collection require no modification.

An important addition has been made to our knowledge of the Central-African
lakes through Mr. Moore’s investigation of Lake Kivu, to the north of Tanganyika,
and overflowing into the latter through the Rusisi River, but without any communica-
tion with any other basin, and this investigation has failed to throw any light on the
problem of the halolimnic fauna. With regard to the piscine inhabitants of Kivu, the
information gained goes simply to show that its waters are very thinly populated.
Its former connection with the Nile, at probably no very remote period, geologically
speaking, as ascertained by the Expedition, may account for the presence of Tilapia
nilotica, a species which has not been found in the Tanganyika nor in the Congo
Basin. Along with it were obtained examples of another Ti/apia (T’. burtont) previously
known from Tanganyika, a Paratilapia (P. bloyeti) described from Kast Africa, a new
species of the same genus, and a new Barbus. No representatives could be found of
any of the numerous generic types of Cichlide which are the essential feature of the
fish-fauna of the great lake.

The number of specimens brought home on this occasion from Tanganyika and
Kivu amounts to 190, representing 50 species, 26 of which were new to science,
obtained at the following localities, enumerated from south to north, as well as from
far out in Lake Tanganyika :—

Kinyamkolo, extreme south end of Lake Tanganyika.
Kalambo, 8.E. of lake.

Tembwi, W. coast, 35 or 40 miles 8. of Albertville.
Msambu, E. coast, S. of middle.

Kibogo, E. coast, middle of lake.

Kibwesi, near Kibogo.

Maswa, 1. coast, about 50 miles S. of Ujiji.
Usambura, N. end of lake.

Rusist R., at mouth.

Rusisi R., at source.

L. Kivu.

In the introduction to the first Report, I tabulated the species then known from

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 139

Lake Tanganyika and made up a list of 43 species. Through the collections formed
since by the Officers of the Congo Free State and by Mr. Moore, the number has now
risen to 91—that is, nearly as many as are known from the Nile (anadromous and
catadromous species not included). Out of these 91 species it has been my privilege
to describe as many as 74, and I beg on this occasion to express my most grateful
thanks to my friend Mr. Moore, and to my fellow-countrymen in the service of the
Congo Free State, for having placed in my hands the valuable material brought home

at the cost of so great perils and hardships.

List of the Fishes of Lakes Tanganyika and Kivu,

The names of the genera and species peculiar to these lakes are printed in italic,
the others in roman, in the Table (pp. 140-141).

The 7 columns refer to the various collections on which the list is based :—

1. Mr. Coode Hore’s Collection (Giinther, P. Z.S. 1893, p. 628).

Mr. Moore’s first Collection (Boulenger, Tr. Zool. Soc. xv. 1898, p. 1).
Capt. Descamps’s Collection (Boulenger, /. ¢.).
Lieut. Lemaire’s Collection (Boulenger, op. cit. 1899, p. 87).
Capt. Hecq’s Collection (Boulenger, Ann. Mus. Congo, Zool. i. 1899 & 1900).
Mr. Moore’s second Collection from Tanganyika.

7. Mr. Moore’s Collection from Kivu.
In the eighth column the range outside the Tanganyika district is indicated.

Oo Or BR Oy

The following deductions may be drawn from the Table :—

1. Endemic genera occur only in the family Cichlide, but these are remarkably
numerous (17), nearly equalling in number those known from ail other parts
of the world.

. Most of the species of Cichlide and all the Cyprinidew and Mastacembelide are
endemic, whilst all the Characinide and one-half the Siluride@ have a much
wider range.

. Not one of the collections yet made contains representatives of much more
than one-half of the known species !, and out of the six species represented
in the first collection (Mr. Coode Hore’s) only three have been rediscovered.

Lo

(3)

1 Mr. Moore wishes me to observe, however, that, owing to the difficulties of transport, he abstained in
many cases from preserving specimens of the species which he felt certain of having obtained on his first
expedition. The fact nevertheless remains that the collections made by him are so far from being duplicated
by those received from the Belgian explorers as to show our knowledge of the Fishes of the lake to be still
far from complete. Although Mr. Moore fished not far from Albertville, it is surprising how many species
discovered about the latter place by Capt. Hecq are unrepresented in his collection. He also fished near
Ujiji, and yet examples of only two out of the six species described by Dr. Giinther from Mr. Coode Hore’s

collection have turned up again.
y 2

140 MR. G. A.
PoLyPreRiIDA.
1. Polypterus congicus Blgr. 1898. .

LepiposIRPNIDA.

BOULENGER ON A COLLECTION

Congo.

2. ? Protopterus wthiopicus Heck. 1851 | Upp. Nile, E. Africa.
| |
CHaRacinID”. | | (E Na
3. Hydrocyon lineatus Blkr. 1863.......... | x | x | *& | x | . | Senegal to Congo,
4. Alestes macrophthalmus Gthr. 1867...... re eseen| * | * | * | .- | Congo, Gaboon,
5. ,, macrolepidotus C.& V.1849 ....| .. | » eee [oo Ms |i wet NGS [Ogowe.
6. Citharinus gibbosus Blgr. 1899.......... || es | * Congo.
| hea
| |
CyPRINID&.
7. Capoéta tanganice Blgr. 1900 .......... |
8. Barbus platyrhinus Blgr. 1900 .......... | | x |
Qe eltianaliseBlor elo OOMe reer | |[seseeal bse
105° 5) Garrard, UOO) sonboodoooec | x |
Een mczopidolepissblonwl O00 vrreesctrer. fy |) es |
| 12. Barilius moorii Blgr. 1900.............. | ls |
118}, i anganicesBloraslO0 Omen erate | a3 ||
SILURIDR. | |
14. Clarias robecchii Vincig. 1893 .......-.. | % Somaliland,
165 og = aap afoating Iliere, WINS coaocosace so |e | | | [ Zanzibar.
16. Chrysichthys cranchii Leach, 1810 ...... feral eyall save rae onl ese aera || Mee | Congo.
Nee Hy myriodon Blgr. 1900 ...... 22 || oo |] oo loo || 3 Ile |
18. a brachynema Bler.1900 ....| .. | .. | .. | .. 1] -- | x | |
19. Auchenoglanis biscutatus Geoffr. 1829....| .. | » | .. | « | x | «x | .. | Nile, Trop. Africa. |
20. Anoplopterus platychir Gthr. 1864 ...... oo || ¢3 || oo |) oo || oo oo |} co || Bo Aliiga, Niassa,
21. Synodontis granulosus Blgr. 1900........ atop eb | x
22. “s multipunctatus Blgr. 1898 ....| .. | » | .. | * | x | # |
23. Malopterurus electricus Lacép. 1801...... ao. ill 23 | * | * | * . | Nile, Trop. Africa.
| | |
CYPRINODONTID®, | | | |
24. Haplochilus tanganicanus Bler. 1898 ....) .. | % | .. | # | |
SERRANIDH.
25. Lates microlepis Blgr. 1898 ............ ok Sean cen tee
CIcHLIDZ. |
26. Lamprologus tetracanthus Blgr. 1899 ie *
27. a elongatus Blgr. 1898 ...... pe erat sien Wem euler sn |
28. 9 tretocephalus, Bier 899) eee etn ite estou sean]
29 5 modestus Blgr. 1898 ........ * x
3C. an UGCA Mess MEEN) Aoacwoo|) oo |) so |) a5 |) fs | co |) =
31. * hecqui Blgr. 1899.......... Rese x |
32. 4 Moore eral S98 acres eras |e
33. * GreviseBloria| S99 eier Weert co |! oo Moe J) es
34. 5 compressiceps Bler. 1898 .... x
35. . fasciatus Blgr. 1898 ...... 5 he
36. 53 furcifer Blgr. 1898 ........ * i

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 141

ie |) ee | 6 Et Ge I |
| | |
37. Julidochromis ornatus Blgr. 1898 ........ ao. || «% |
38. Paratilapia vittata Bler. 1901 Jove oogote Pen ee eye alheee ales (kee “k
39, BS aurita Bler. EO OT ee aeetees peas Fev eset iereraoetce lh eevee eee
40. Pe bloyeti Sauv. SSS i eee ene aft oo iliac | ac loo | oe |) cs | Io Auta,
41. 3 fapeyare We, WINS oo cccadgu3 loo ||
42, H calliurceD lors 9 Ole ee eee “eae || eae |leceaced estan lense eae
43. Fi macrops Blory 898. ae. * Be
| 44. 5 ventralis Blor. 1898). ao. see 50 || &3 |
| 46. es dewindti Blgr. 1899 ........ 66 | do ll oo || #3
46. » furcifer Blgr. 1898 .......... POS |
| 47. - stenosoma Blgr.1901 ........ Rrra *
| 48. 5 leptosoma loser, USS, coonesuc oo |} es *%
49, nigriptrnis Bler. 1901 Pepa rae eaten cess lly woe|| ees
50. Bathybates ferow Blgr. 1898 DyeaNolap averse oo |) €% | oo | es | |e
ole os fasciatus. Bier lO Ore tyr avec Nt ifs, ||iimeecean Neat [iat (Hac
52. Pelmatochromis polylepis Wika WOM oS osal) au || co || oo | os | es. | ee
| 53. Hetodus descampsii Blgr. 1898 .......... 50 jac) ea |
| 54. 4, melanogenys Bigr. 1898 ........ 6] oo |] ea || ex
| 5d. 3. Longtanals) Bler: 1899-2225... . &% loo || #3
56. Aenotilapia Sire Ales: WS) os cc0a080n 08 ay eee lle * * |
57. < ornatipinnis Blgr. 1901 ...... sgt ll syec [lee seat | oom ean Pie
58. Grammatotria lemairii Blgr. 1899 ...... sok eens x | * |
59. Trematocara marginatum Blgr. 1899 Bll casas || bac t\| °3 * %
60. 3 unmaculatum Bler, 1901.3) 55 || a= |) ae |) ae) ee se |
61. Telmatochromis vittatus Blgr. 1898 ...... 6 | & |
62. - UE woRHOS Weitere EIS) Gesell on |) £3 Il oo || ou |) es || &e |
63. Gephyrochromis moorti Blgr. 1901 ...... Bes) Picsestl ee esse meee ee
64. Tropheus\moortt Blgr. 1898 ............ no
65. FA annectens Blgr. 1900 .......... 56 | 0 foo |} oo |] & | |
66, Simochromis diagramma Gthr. 1893...... ema al hae eral log. ||: <4
Gree lilapiamil obicawlinle/ Ol ermerrrcteirier pa || 50 || bo || 6 || oo, |} oo || em | Sime Wille seme |
G8, fs emt Gide, EOS 36 on co conn | on i) oo | oo | eh co || £4 [gambia, Niger.)
CO, = Word Cine NES .ooccocacunc0c %
70. » rubropunctata Blgr. 1899........ 60 || oo |} oo | 23 |e
le g, akemdlaopos Where, WEB) socoocanes 56 oat || o6 |) ea ll es ll &
eh, op Calon Jollee, USS oon coueouo cn 50 || €3 ll oe |] es il es || es
ote pleurotcenianb ler lO Olmert). Sareib| i see ices esse itches (MSE
74. ,, trematocephala Blgr.1901 ...... x
WS og logos ible, INO so sconccdoo0 od ay | ool Seal celiac, |e
iCute semegrandoculis Dorel SO OM acer FEM ae mt incre il lee |
| ate microlepis Bler. SE co ob o9da0050 se || 66 || oo Hey | es Me |
78. Patrochromis polyodon Inkege, WES ooscooon oo || | |
19s i tanganice Gthr. WEE soneoe m& 50 || oo ||oo || ea gs
80. Asprotilapia leptura Blgr. 1901 ........ a ee. ses Nose alliio.ce Ale
81. Hretinodus cyanostictus Blgr. 1898........ Bia edi ae. l| oo ||
82. Spathodus erythrodon Blgr. 1900 ........ soe llsao! |) oe loon |e
83. Perissodus microlepis Blgr. 1898 ........ Saale | |
84. Xenochromis hecqui Blgr. 1899 .......... Sree ||) cero ee ay | ere * BS |
85. Plecodus paradowus Blgr. 1898 .......... Patil) cesol le ace eaieeel rae
MastTacEMBELID®.
86. Mastacembelus frenatus Blgr. 1901 ...... oe | eter leet litera err IRS
87. moorvt Blgr. 1898 ........ a |
88. 5 ellipsifer Blgr. 1899 ...... Sos) lec {ll eave | ccackel farses
89. e tanganice Gthr. 1893 ....) x
90. 4 teniatus Blgr. 1901 ...... o¢ |l oo || oo || co || oo | es
91. 5 ophidium Gthr. 1893 ....) » |

142 MR. G. A. BOULENGER ON A COLLECTION

4

I am therefore disposed to conclude that we do not know much more than one-half
of the species which will ultimately be found to inhabit Lake Tanganyika.

As regards facts of distribution, I can only emphasize again the quite extraordinary
abundance and variety of the Cichlide, the salient feature of the Lake which might be
named the kingdom of the Cichlidew: 60 species (divided into 21 genera), being more
than are known from the whole of the rest of Africa (including Madagascar) with
Syria, and about as many as can be listed from South America.

As to the affinity shown by the Tanganyika Fish-fauna to other basins of Africa,
we may at once dismiss all connection with Nyasa and the Zambesi. Of the genera
that are not ubiquitous in Tropical Africa, two (Capoéta and Anoplopterus) have
representatives in East Africa only, and two (Lamprologus and Pelmatochromis) in the
Congo and West Africa only; whilst of the species, five occur also in the Nile or East
Africa, and four inthe Congo. We are therefore justified in concluding that this fauna
shows no more special affinity to the one watershed than to the other.

List of the Fishes represented in the Collection, with Descriptions of the new
Genera and Species}.

CROSSOPTERYGII.

POLYPTERIDS.

1. Potyprerus coneicus Bler.

Four specimens were brought home of the large Polypterus observed by Mr. Moore
on his first visit, and identified by him under the provisional name of P. bichir. ‘They
prove to be referable to the allied species from the Congo, described by me in 1898 as
P. congicus (Ann. & Mag. N. H. [7] ii. p. 418).

Particulars are appended of the four specimens, from the middle of the lake off
Kalambo, at about 5 fathoms, caught in trammel-nets :—

il 2 3. 4.
Motalulensthyankmullimetres) eee aieeetet ner 620 580 530 520
Length of head (in millimetres) .................... 130 110 105 100
Numbextofidorsallspines| rma noeiere iene 13 13 14 13
Number of scales along the side.................... 56 55 57 57
Number of scales round the body .................. 47 A7 7 AT
Number of scales between occiput and first dorsal spine. 14 14 12 13

A small azygous shield usually separates the nasals in this species; it is, however,
absent in two of the specimens (3, 4).

‘ Of which preliminary diagnoses haye already appeared in Ann. & Mag. N. H. (7) vi. 1900, p. 478, and
vii. 1900, p. 1,

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 145

The dark transverse bands, 6 to 8 in number, characteristic of this species, are very
strongly marked in one of the specimens.

The ascertained range of this Polypterus in the Congo is from the region of the
cataracts to the Stanley Falls.

TELEOSTEI.
CHARACINIDA.

2. ALESTES MACROPHTHALMUS Gthr.
When this species was first recorded from Lake Tanganyika, it was only known
from the Gaboon. It-has since been found in Lake Mweru and in the Congo.

5, ALESTES MACROLEPIDOTUS C. & V.

Kalambo.

4, CITHARINUS GIBBOSUS Bler.

Kalambo. ‘The largest specimen measures 500 millim.

When I described this fine fish from the Congo, I expressed the opinion that it
would probably turn out to be the same as one of which I had seen a coloured sketch
made by Mr. Moore on his first expedition.

CYPRINIDS.

5. CAPOETA TANGANICH. (Plate XII. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 478.

Depth of body 32 to 4 times in total length, length of head 5 times. Snout broad
and rounded, as long as or slightly longer than the eye, the diameter of which is
34 times in the length of the head and nearly twice in the interocular width; the
width of the mouth equals 3 that of the head; a minute barbel, hidden under the lip
at the angle of the mouth. Dorsal III 9; third ray very strong, ossified, smooth; the
fin, which is equally distant from the eye and from the caudal, has the free edge notched,
and its greatest depth equals the length of the head. Anal III 5; the longest ray
measures } the length of the head. Pectoral acutely pointed, as iong as the head, not
reaching the ventral, which is inserted under the first rays of the dorsal. Caudal

forked. Caudal peduncle twice as long as deep. Scales 68-70 — 9 or 10 between
the lateral line and the root of the ventral. Olive above, each scale darker at the base,
silvery white beneath ; fins greyish.

Total length 320 millim.

Three specimens from the north end of Lake Tanganyika.

The discovery of a species of this genus in Lake ‘Tanganyika is particularly
interesting from the fact that only one was known from Africa, viz. the Abyssinian

144 MR. G. A. BOULENGER ON A COLLECTION

C. dilloni C. & V.; this is distinguished by the absence of barbels and the greater
size of the scales (30 to 32 in the lateral line). In the presence of a pair of barbels
and the small size of the scales, C. tanganicw belongs to the typical section of the
genus, inhabiting South-western Asia; but it has the enlarged dorsal ray neither feeble
as in C, fundulus Pall. and allied species, nor serrated as in C. trutta Heck.

6. Barsus piatyruinus. (Plate XII. fig. 2.
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 479.

Depth of body 34 times in total length, length of head 4 times. Snout broad and
rounded, twice as long as the diameter of the eye, which is contained 5} times in the
length of the head and 23 times in the interocular width ; mouth small, with two pairs
of subequal barbels, the length of which equals the diameter of the eye. Dorsal III 8;
third ray not enlarged, not serrated; the fin, which is equally distant from the eye and
from the caudal, has the free edge convex. Anal III 5, tle longest ray not quite 2
the length of the head. Pectoral a little shorter than the head, not reaching the
ventral, which is inserted below the middle of the dorsal. Caudal forked. Caudal
peduncle 13 as long as deep. Seales 40 ae, 34 between the lateral line and the root
of the ventral. Olive-brown above the lateral line, golden yellow beneath.

Total length 390 millim.

A single specimen from south of Usambura.

This species appears to be more nearly related to B. capensis, Smith, from which it

differs in the much shorter and broader snout.

7. BARBUS ALTIANALIS. (Plate XIII. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 479.

Depth of body equal to or slightly greater than the length of the head, which is
contained 4 to 44 times in the total length. Snout moderately broad, rounded, scarcely
projecting beyond the lower jaw, 13 to 13 times as long as the diameter of the eye,
which is contained 5 to 54 times in the length of the head and twice to twice and
one-fourth in the interocular width; mouth small, with two pairs of subequal barbels,
the length of which equals or exceeds a little the diameter of the eye. Dorsal III-IV 9;
third or fourth ray very strong, ossified, not serrated; the fin, which is equally
distant from the occiput and from the caudal, has the free edge notched and its
greatest depth is but slightly less than the length of the head. Anal HII 5; the
longest ray measures about § the length of the head; the fin, when folded, reaches
nearly the root of the caudal. Pectoral a little shorter than the head, not reaching the
ventral, the first ray of which corresponds to the origin of the dorsal. Caudal forked.
Caudal peduncle nearly twice as long as deep. Scales 34-35 a 3 between the lateral
line and the root of the ventral. Olive-brown, very dark above.

Total length 450 millim.

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 145

Two specimens from Lake Kivu and one from the source of the Rusisi River.

B. altianalis is extremely closely related to B. mariquensis Smith. It differs only
in the somewhat broader snout, the stronger third dorsal ray, and the somewhat longer
caudal peduncle.

8. BARBUS SERRIFER. (Plate XIV. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 479.

Depth of body 3 to 35 times in total length, length of head 4 to 44 times. Snout
rounded, uot projecting beyond the lower jaw, as long as or a little longer than the
diameter of the eye, which is contained 4 to 43 times in the length of the head and 14
to 15 times in the interocular width; mouth small, with two pairs of barbels, the

1
5)

posterior of which are the longer and measure twice the diameter of the eye. Dorsal
III 7; third ray very strong, ossified, serrated behind; the fin, which is equally
distant from the eye and from the caudal, is not notched and the largest ray is a little
shorter than the head. Anal III 5, the longest ray 2 the length of the head. Pectoral
? to $ the length of the head, reaching, or nearly reaching, the base of the ventral, the
last ray of which falls under the first of the dorsal. Caudal forked. Caudal peduncle
1d to 1§ as long as deep. Scales 28-30 a 3 between the lateral line and the root

of the ventral. Olive-brown above, silvery white beneath ; a greyish stripe along each
side of the body above the lateral line; a small blackish spot at the base of the
caudal.

Total length 120 millim.

Three specimens from the north end of Lake Tanganyika.

Allied to B. kesslert Stdr. Distinguished by the smaller eye. the longer barbels.
the more numerous scales, and the presence of only 7 branched dorsal rays.

9. BARBUS TROPIDOLEPIS. (Plate XIII. fig. 2.)

Bouleng. Ann. Mus. Congo, Zool. i. p. 133, pl. xlix. fig. 2 (1900).

Depth of body 3 times in total length, length of head 4 to 44 times. Snout broad
and rounded, strongly projecting beyond the mouth, 14 to twice as long as the diameter
of the eye, which is contained 45 to 55 times in the length of the head and 2 to 24
times in the interocular width; mouth small, inferior; a minute barbel almost entirely
concealed in the angle of the lips. Dorsal III 9; third ray very strong, ossified, not
serrated, its length at least $ that of the head; the fin, which is equally distant from the
occiput and the root of the caudal, is notched. Anal II 5, the longest ray about 2 the
length of the head. Pectoral about # the length of the head, not reaching the base of
the ventral, the first ray of which falls under the origin of the dorsal. Caudal forked.
Caudal peduncle 13 to 1? as long as deep. Scales 44—46 BD 5 between the lateral

line and the root of the ventral; in breeding specimens, the scales, those at least
which are above the lateral line on the caudal portion of the body, bear a median
VOL. XVI.—ParT 11. No. 2.—Octoder, 1901. Y

146 MR. G. A. BOULENGER ON A COLLECTION

swelling or obtuse keel, these keels forming together very regular longitudinal lines.
Olive above, silvery white beneath.

This handsome fish, which grows to a length of three feet, and the flesh of which is
much esteemed, was discovered almost simultaneously at Albertville by Capt. Hecq and
at Usambura by Mr. Moore.

10. Bariivs moor. (Plate XIV. figs. 2, 2 a.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 480.

Depth of body equal to length of head, 4 times in total length. Head a little over
twice as long as broad, with slightly curved upper profile ; snout pointed, not extending
beyond the Jower jaw, as long as or a little longer than the diameter of the eye, which
is contained 4 to 44 times in the length of the head; interorbital width a little greater
than the diameter of the eye; mouth extending to below the anterior third or the
centre of the eye; no barbels; the naked space between the preopercle and the
suborbitals less than half the width of the latter. Gill-rakers very short, almost
rudimentary, 8 on lower part of anterior arch. Dorsal III 9, originating at equal
distance from the anterior border of the eye and the root of the caudal; its border is
not notched, and its depth equals about 3 the length of the head. Anal III 13-14,
originating under the middle of the dorsal ; its anterior rays a little longer than those
of the dorsal and much longer than the posterior rays, forming a rounded lobe.
Pectoral pointed, shorter than the head, not reaching the ventral, which extends to the
origin of the anal. Caudal forked. Caudal peduncle twice as long as deep. Scales
56-60 12! 3 between the lateral line and the root of the ventral. Silvery, brownish
on the back; more or less distinct dark vertical bars on the side of the body, about 10
in number; dorsal blackish at the end.

Total length 115 millim.

Several specimens from the north end of Lake Tanganyika.

11. Baritius TaNGANICH. (Plate XIV. figs. 3, 3 a.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 480.

Depth of body equal to length of head, 44 times in total length. Head a little over
twice as long as broad, with straight declivous upper profile; snout very pointed, not
extending below the lower jaw, once and a half the diameter of the eye, which is con-
tained 54 times in the length of the head; interorbital width once and a half the
diameter of the eye; mouth extending to below the posterior border of the eye; no
barbels; the naked space between the precpercle and the suborbitals about 3 the width
of the latter. Gill-rakers short, 10 on lower part of anterior arch. Dorsal III 10,
originating at equal distance from the occiput and the root of the caudal, the posterior
third of its base above the anal; its anterior rays are longest, measuring a little more
than half the length of the head. Anal III 17, strongly notched, with rounded

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 147

anterior lobe, the longest rays of which measure % the length of the head, whilst the
posterior rays measure barely 4. Pectoral pointed, ? length of head, not reaching the
ventral, which extends to the vent. Caudal forked. Caudal peduncle a little over
twice as long as deep. Scales 82 = 4 between the lateral line and the root of the
ventral. Silvery, olive on the back ; 16 or 17 blackish vertical bars on each side of
the body, equally distant from the median dorsal line and from the lateral line.

Total length 260 millim.

A single specimen from the north end of Lake Tanganyika.

B. tanganice is nearly related to B. (Pelotrophus) microlepis Gthr., from Lake
Nyasa. It is distinguished from it by the lesser number of scales between the lateral
line and the ventral fin and the greater approximation of the ventral to the anal.

SILURID&,

12. CHRYSICHTHYS MYRIODON.

Bouleng. Ann. Mus. Congo, Zool. i. p. 139, pl. li. (1900).

Depth of body 44 times in total length, length of head 34 to 34 times. Head broad
and much depressed, ¢ longer than broad, rough on the vertex and occiput; snout
broadly rounded, scarcely projecting beyond the lower jaw, 4 length of head, and twice
the diameter of the eye, which is contained 6 times in the length of the head and 2 to
24 times in the interocular width; the occipital process, which is rough like the
occiput, in contact with the interspinous shield; nasal barbel #2 or # the diameter of
the eve: maxillary barbel a little more than half the length of the head; inner
mandibular barbel 3 length of head, outer a little less than half. Vomero-pterygoid
teeth very fine and closely set, as are also the premaxillary and mandibular teeth,
forming a broad, horseshoe-shaped, uninterrupted band; its width in the middle a little
less than that of the premaxillary band, but increasing at the sides, where it much
exceeds the latter. Dorsal 1 6; spine rugose, not serrated, nearly half the length of
the head and # or $ the length of the longest soft rays. Adipose dorsal a little longer
than deep, its base # that of the rayed dorsal and 4 the distance which separates it
from the latter. Anal IV 8-9. Pectoral spine a little longer and stronger than the
dorsal, feebly striated, and bearing on its inner edge about 20 strong retrorse serre.
Ventral not reaching the anal. Caudal deeply notched, with obtusely pointed lobes ;
the longest rays measuring double the length of the median. Caudal peduncle 13 to
twice as long as deep. Olive-brown above, white beneath.

Total length 470 millim.

This description is taken from three large specimens—one received from Albertville
by the Congo Museum, through Capt. Hecq, one from Tembwi, and one from
Kinyamkolo, brought home by Mr. Moore. Compared with specimens of C. cranchit of
similar size, C. myriodon differs by its smaller and more numerous teeth, the greater
posterior width of the vomero-pterygoid band, the larger eye, and the more strongly

serrated pectoral spine. It has also a higher number of vertebra (20+ 27).
Z2

148 MR. G. A. BOULENGER ON A COLLECTION

Young specimens, measuring up to 130 millim., collected at Kibwesi, in deep water,
by Mr. Moore, may, I think, be referred to this species. The depth of the body is 5 or
6 times in the total length ; head + or 4 longer than broad ; diameter of the eye 54 to
32 times in the length of the head, 14 to 13 in the interocular width; maxillary barbel
2 to 8 the length of the head; vomero-pterygoid teeth forming a narrow subcrescentic

9

band, slightly interrupted mesially. Base of adipose dorsal 3 or | its distance from the
rayed dorsal; anal IV 8-10; 7 to 9 very large retrorse serre on the inner side of
the pectoral spine. A blackish spot at the end of the dorsal, and another on each lobe

of the caudal.

13. CHRYSICHTHYS BRACHYNEMA. (Plate XV.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 480.

Depth of body 4 to 5 times in total length, length of head 53 to 53 times. Head
broad and much depressed, + or ¢ longer than broad, covered with thick smooth skin ;
snout much flattened, twice as broad as long, broadly rounded, projecting a little
beyond the lower jaw, its length 3 that of the head; diameter of the eye 13 to twice
in the length of the snout, 5 or 6 times in the length of the head, and 2 or 23 in the
interocular width ; occipital process hidden under the skin, but reaching the inter-
neural shield: nasal barbel as long as or slightly longer than the diameter of the eye in
the young, 2 the diameter of the eye in the adult; maxillary barbel $ or 3 the length
of the head; outer mandibular barbel 4 or 4 the length of the head, inner } or 4.
Vomero-pterygoid teeth forming a broad crescentic or horseshoe-shaped band, uninter-
rupted or narrowly interrupted mesially ; this band as broad as the preemaxillary band
in the adult, also widening behind, narrower and more tapering behind in the young.
Dorsal I 6 ; spine very feebly serrated in front and behind, covered with a thick skin,
its length 2 that of the head and a little shorter than the soft rays. Adipose dorsal 13
to twice as long as deep, its base hardly equai to that of the rayed dorsal and 3 or 4 its
distance from the latter. Anal IV 8-9. Pectoral spine thicker and longer than that
of the dorsal, armed on its inner side with strong retrorse serre. Ventral not reaching
the anal. Caudal deeply notched, with obtusely pointed lobes, the longest rays twice
to twice and a half as long as the middle ones. Caudal peduncle 13 to 13 as long as
deep. Olive above, white beneath.

Total length 400 millim.

Several specimens from Kalambo and Usambura.

This species is also closely allied to C. cranchii, but may be distinguished from it by
the absence of rugosities on the skull, the shorter head, and the shorter mandibular
barbels.

14. AUCHENOGLANIS BISCUTATUS Geoffr.

Kalambo ; also far out, in deep water.

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 149

15. SYNODONTIS GRANULOSUS. (Plate X V1.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1900, p. 480.

Body feebly compressed, its depth equal to the length of the head and contained 3
to 34 times in the total length. Head not or but slightly longer than broad, feebly
depressed, covered with granular asperities; frontal fontanelle rather narrow; snout
rounded, a little more than half the length of the head; eye directed upwards, its
diameter 53 to 6 times in the length of the head, 24 to 2% times in the width of the
interocular region, which is slightly convex; no occipital keel. Lips moderately
developed ; maxillary barbel simple, as iong as or a little longer than the head, and not
extending beyond the anterior third of the pectoral spine ; mandibular barbels inserted
on a straight transverse line, the outer ~ or 2 the length of the head and thrice that of
the inner, both with very short branches, especially near the base, where they are
tubercular. Preemaxillary teeth small and numerous, forming a broad band ; anterior
mandibular teeth small, feebly curved, hardly 4 the diameter of the eye, and numbering
40 to 42. Gill-cleft not extending inferiorly beyond the base of the pectoral fin.
Occipito-nuchal shield rugose, tectiform, a little longer than broad, ending in two
rounded points which extend to the level of the base of the first soft dorsal ray.
Humeral process covered with granular asperities, keeled, narrow, and sharply pointed,
extending nearly as far back as the occipito-nuchal shield. The skin of the whole body,
including the adipose fin, covered with small, closely-set, granular papille. Dorsal I 7 ;
spine rather strong, 14 times as long as the base of the fin, striated and armed behind
with 10 to 15 retrorse serree. Adipose dorsal 4 times as long as deep, 24 to 34 times
as long as its distance from the rayed dorsal. Anal III 8. Pectoral spine very strong,
as long as that of the dorsal, striated, feebly denticulate on the anterior border, with
15 to 17 strong retrorse serree on the posterior border. Ventral not reaching anal.
Caudal deeply notched. Olive above, yellowish beneath ; dorsal, anal, and paired fins
black in front, orange behind ; caudal black, with a broad orange posterior margin.

Total length 250 millim.

Three specimens from the north end of Lake Tanganyika, in rather deep water.

16. SYNODONTIS MULTIPUNCTATUS Blgr.
Kalambo.

17. MaLopreRuURuUS ELEcTRICUS Lacép.
Kalambo.

SERRANIDA,
1. LatTEs MICROLEPIS Bley.

Kinyamkolo, and middle of lake, in deep water.
Mr. Moore has satisfied himself that the ferocious fish, over four feet long, attacking

150 MR. G. A. BOULENGER ON A COLLECTION

the paddles of boats, to which the late K. J. Glave first drew attention (‘ Century
Magazine, liii. 1897, p. 902), is no other than the adult of the Lates discovered by him,
and which was described in the first Report from young specimens.

CIicHLID4.
19. LamMpPRoLoGus LEMAIRIL Blgr.

Specimens obtained at Kibwesi and at Msambu show this fish to grow to a length
of 230 millim. It is by far the largest species of the genus.

20. LAMPROLOGUS FURCIFER Blgr.
Msambu.

21. ParatiLaPia vitraTa. (Plate XVIII. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 1.

Depth of body 34 to 34 times in total length, length of head 23 to 3 times. Profile
of snout convex ; lower jaw projecting beyond the upper; diameter of eye 13 to 13
times in length of snout, 4 to 4% times in length of head, and equal to interocular
width ; maxillary extending to below anterior border of eye; teeth in 3 or 4 rows, the
outer much larger than the others; 3 or 4 series of scales on the cheek ; large scales
on the opercle. Géill-rakers short, 10 to 12 on lower part of anterior arch. Dorsal
XV-XVI 8-9; spines subequal from the seventh or eighth, which measures about
2 length of head and 3 longest soft rays. Pectoral pointed, about § length of head.
Ventral reaching vent or origin of anal. Anal IT] 8-9; third spine longest, as long
as middle dorsal spines. Caudal feebly emarginate. Caudal peduncle 15 times as
long as deep. Scales with finely denticulate border, 33-35 ae lat. 1. a = Olive
above, whitish beneath ; a blackish stripe on each side above the upper lateral line,
and a second from the opercle to the root of the caudal fin, passing over the lower
lateral line; dorsal, anal, and caudal fins greyish or blackish, ventrals black in the
males.

Total length 120 millim.

Several specimens from Lake Kivu.

22. PARATILAPIA auRITA. ( Plate XIX. fig. 2.)
Bouleng. /. ¢. p. 2.

Depth of body 3 to 34 times in total length, length of head 3¢ to 33 times. Snout
short, as long as or a little shorter than the eye, with slightly curved upper profile ;
lower jaw not projecting beyond the upper; diameter of eye 34 to 3} times in length
of head, equal to or greater than interocular width; maxillary extending to below
anterior fourth or third of eye; teeth in 2 or 3 rows, the outer much larger than the
others ; 4 or 5 series of scales on the cheek ; large scales on the opercle. Gill-rakers

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 151

short, 10 or 11 on lower part of anterior arch. Dorsal XV-XVII 9-10; spines
increasing in length to the last, which is a little less than half length of head; the
longest soft rays produced into filaments, and only a little shorter than head, Pectoral
pointed, as long as head. Ventral produced in a filament, and extending to vent or
beyond. Anal III 8; third spine stronger and shorter than the last dorsal spine.
Caudal feebly emarginate. Caudal peduncle 13 times as long as deep. Scales with
finely denticulate border, 35-36 — lat. 1. = Brownish, with or without oblique
cross-bars of mother-of-pearl or silvery white, sometimes with ill-defined dark bars
across the back; a very distinct, blue-black, opercular spot; dorsal and anal grey or
blackish, often striated or spotted with white; the membrane between the dorsal
spines edged with black ; anal sometimes blackish.

Total length 150 millim.

Numerous specimens from Msambu.

25. PARATILAPIA BLOYETI Sauvage.

Lake Kivu. I have compared the specimens brought home by Mr. Moore with one
of the type specimens from Kandoa, Usagara, German Kast Africa.

24, PARATILAPIA CALLIURA. (Plate XIX. fig. 3.)
Bouleng. Ann. & Mag. N. H. (7) vi. 1901, p. 2.

Depth of body 4 to 43 times in total length, length of head 3 to 33 times. Snout
pointed, with straight upper profile, as long as or a little shorter than the eye, the
diameter of which is double the interocular width and is contained 3 to 33 times in
length of head; lower jaw projecting beyond the upper; maxillary extending to
below anterior fourth of eye; teeth small, in two rows; 2 or 3 series of scales on the
cheek ; large scales on the opercle. Gill-rakers moderately long, 15 on lower part of
anterior arch. Dorsal XVI-XVII 10; spines increasing in length to the last, which
measures ? or 4 length of head; longest soft rays % or ? length of head. Pectoral
pointed, a little shorter than head. Ventral reaching vent. Anal III 7-8; third
spine longest, a little shorter than last dorsal spine. Caudal feebly emarginate.
Caudal peduncle 14 times as long as deep. Scales with finely denticulate border,
37-40 ae lat. 1. — Pale brownish above, silvery beneath ; a blackish opercular
spot; dorsal and anal edged with black ; 4 or 5 black bars across the caudal; young
with black bars across the dorsal.

Total length 110 millim.

Several specimens from Kalambo.

25, PARATILAPIA STENOSOMA. (Plate XVII. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 2.
Body very strongly compressed, its depth equal to the length of the head and

152 MR, G. A. BOULENGER ON A COLLECTION

contained 2% to 3 times in total length. Profile of snout descending in a straight or
slightly convex line ; lower jaw projecting beyond the upper ; diameter of eye nearly
equal to length of snout or interocular width, 34 to 33 times in length of head ;
maxillary not extending to below anterior border of eye; teeth small, in 2 or 3 rows,
the outer very slightly larger than the others; 2 series of scales on the cheek; very
thin scales on the opercle. Gill-rakers rather long and closely set, 19 to 23 on lower
part of anterior arch. Dorsal XV 13; last spine longest, 2 length of head ; soft rays
longer, sometimes produced into filaments. Pectoral pointed, a little shorter than
head. Ventral reaching vent. Anal III 12-15; third spine longest, a little stronger

but shorter than last dorsal spine. Caudal deeply emarginate. Caudal peduncle nearly
sar
Brownish above, silvery beneath, with or without blackish spots and longitudinal bands ;
dorsal blackish at the end.

Total length 220 millim.

Several specimens from Maswa and from the south end of Lake Tanganyika.

twice as long as deep. Scales without marginal denticulation, 60-68 ae lat. 1.

26. PARATILAPIA LEPTOSOMA Bler.
Msambu.

27. PARATILAPIA NIGRIPINNIS. (Plate XIX. fig. 1.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 3.

Depth of body 4 times in total length, length of head 3 to 54 times. Snout with
straight upper profile, as long as diameter of eye, which equals interocular width and
is contained 33 times in length of head; mouth extremely protractile; maxillary
extending to below anterior border of eye; teeth very small, in 3 rows; 2 or 3 series
oi scales on the cheek ; opercle covered with scales. Géill-rakers long and thin,
closely set, 20 on lower part of anterior arch. Dorsal XV-XVII 11; spines increasing
in length to the last, which measures 2 length of head; soft rays longer. Pectoral
pointed, as long as head. Ventral reaching origin of anal or beyond. Anal III 8-9;
third spine as long as the last dorsal. Caudal deeply emarginate, the lobes produced
into filaments. Caudal peduncle twice as long as deep. Scales with denticulate
border, 39-40 é plat eal ze Dark brown, lighter beneath; fins blackish, the caudal
edged with white above and beneath.

Total length 80 millim.,

Several specimens from Msambu.

This species is very closely allied to the preceding, but is distinguished by the
number of rays in the dorsal and anal fin (D. XV—XVII 11, A. III 8-9, instead of
D. XTI-XIV 14-16, A. ITI 10-12).

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 153

28. BaTHYBATES FEROX Bler.

Several specimens from the South and West Coasts, from Kalambo, and from
Usambura. I have also examined specimens from Moliro and Albertville. The
species is thus seen to be widely dispersed in the lake, and not confined to great
depths.

29. BATHYBATES FASCIATUS. (Plate XVII. fig. 2.
Bouleng. Ann. & Mag. N. H. (7) vu. 1901, p. 3.

Depth of body 43 times in total length, length of head 33 times. Shape of head
similar to that of the preceding species, but eye smaller, its diameter about twice in
length of snout, 5 times in length of head, and 14 in interocular width; 8 series of
small scales on the cheek ; larger scales on the opercle. 18 gill-rakers on lower part
of anterior arch. Dorsal XVII 16; spines subequal from the fifth, which measures 4
length of head; longest soft rays 3 length of head. Pectoral pointed, 2 length of
head. Ventral not half as long as the distance between its base and the vent. Anal
III 18; spines very weak. Caudal forked. Caudal peduncle twice and a half as long
as deep. Scales very small, 140 in a longitudinal series above the upper lateral line,
= in a transverse series ; lat. |. o Brownish above, white beneath ; a series of large,
rounded, blackish spots on each side of the back above the lateral line, alternating with
a series of vertical blackish bars on each side of the body; on the tail, from the middle
of the soft dorsal, the spots unite into a band which extends to the caudal, and the
vertical bars likewise fuse to form a lateral band; a blackish spot on the opercle,
another at the base of the ventral; two black bands on the dorsal, a basal and a
marginal.

Total length 540 millim.

A single specimen from the West Coast, at Tembwi.

This second species of the remarkable genus Bathybates differs from its congener in
the smaller eye, the more numerous gill-rakers, and the smaller scales.

30. PELMATOCHROMIS POLYLEPIS.

Bouleng. Anu. Mus. Congo, Zool. i. p. 143, pl. li. fig. 1 (1900).

Depth of body 24 to 2% times in total length, length of head 3 to 33 times. Snout
with straight upper profile, 14 times diameter of eye, very deep, its length not
exceeding the width of the preorbital region ; diameter of eye 33 to 33 times in length
of head, equal to or a little greater than interocular width; maxillary extending nearly
to below anterior border of eye; teeth very small, in 4 or 5 irregular rows in both
jaws, the outer somewhat larger; 4 or 5 series of scales on the cheek ; larger scales on
the opercle. Gill-rakers short, lamellar, denticulate, 14 or 15 on lower part of anterior
arch. Dorsal XV-XVI 14-15; spines subequal from the sixth, which measures 3 or

vol. XV1.—Part 11. No. 3.—October, 1901. 2 A

154 MR. G. A. BOULENGER ON A COLLECTION

a little more than 4 length of head. Pectoral pointed, falciform, at least as long as
head. Ventral reaching vent, the outer ray produced into a filament. Anal III 8;
third spine much stronger than dorsal spines, nearly 4 length of head. Caudal

rather deeply emarginate. Caudal peduncle a little longer than deep. Scales with
val 25-31 :
denticulate border, 55-58 3 ; lat. 1. ais the upper extending to below the last spines

or the first soft rays of the dorsal, the lower originating a little behind the shoulder
and extending to the caudal fin. Body golden, olive on the back; purplish streaks
along the dorsal and caudal fins, sometimes forming a wide-meshed network,

Total length 500 millim.

This species was discovered almost simultaneously by Mr. Moore at Kinyamkolo and
Kibwesi, and by Capt. Hecq, of the Congo Free State, at Albertville.

The genus Pelmatochromis had not yet been recorded from Lake Tanganyika.
P. polylepis is very closely allied to P. lateralis Blgy., from the Congo; it differs in
its much smaller scales.

31. Ecropus Loneranauis Blgr, (Plate XIX. fig. 4.)

Several specimens from the north end of Lake Tanganyika, near Usambura.

The females, measuring 95 millim., contain ripe ova, the diameter of which is
2 millim. In the adult male (115 millim.) the upper surface of the snout, the chin,
the middle of the throat, the dorsal and anal fins, and the extremity of the ventrals are
black ; a few large, black, white-edged ocelli on the spinous dorsal, along which runs
a white line, which is also present on the soft dorsal and on the anal; oblique white
lines on the soft dorsal; large, round, white spots on the ventrals!; two crescentic
bands on the caudal, the first grey, the second, marginal, blackish.

The specimens brought home by Mr. Moore have enabled me to make an examina-
tion of the skeleton, which differs very considerably from that of Paratilapia. ‘Three
very low crests, supra-occipital and parietal, extend forwards to between the orbits.
The precaudal vertebree are much fewer than the caudals, 14 of the former as against
24 of the latter, a character, quite exceptional among the Cichlidw, shared by the
genera Xenotilapia and Trematocara ; the ribs are inserted on the parapophyses, the
last pair of which form a hemal arch.

32. XENOTILAPIA ORNATIPINNIS. (Plate XVIII. fig. 2.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 3.

Depth of body nearly equal to length of head, 3% to 33 times in total length. Head
quite similar to that of XY. sima. 15 to 17 gill-rakers on lower part of anterior arch.
Dorsal XIII-XV 12-13; spines subequal from the 5th or 6th, } length of head.

‘ Tn this genus the inner rays of the ventral are the longest.

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 155

Pectoral pointed, as long as or a little longer than the head. Ventral not reaching
anal', Anal II 7-8; third spine ? length of head. Caudal deeply notched, cres-
centic. Caudal peduncle 12 times as long as deep. Scales with denticulate border,

28-52

2 ar 3 T9_12 = Sof 7
34-37 79; lat. 1. 15-18 Pale brownish; a more or less distinct silvery lateral band ;
4-12

spinous dorsal black-edged ; large blackish spots or oblique bars on the dorsal; upper
lobe of caudal edged with blackish ; a chevron-shaped blackish band lower down on
the caudal, disposed asymmetrically.

Total length 110 millim.

Several specimens from Kibwesi.

This species is easily distinguished from X. sima by the shorter body, the fewer anal
rays, and the lower number of scales in a longitudinal series.

The skeleton of Xenotilapia is very similar to that of Hctodus. ‘There are likewise
three low crests on the back of the skull, the vertebre number 13+22 in X. sima,
14+ 20 in X. ornatipinnis, and the ribs are remote from the centres.

99

35. TREMATOCARA MARGINATUM Bley.

Usambura market.

34. TREMATOCARA UNIMACULATUM. (Plate XVIII. fig. 3.
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 3.

Depth of body 3 to 34 times in total length, length of head 23 to 2 times. Snout
with curved upper profile, as long as or a little shorter than the eye, the diameter
of which is nearly double interorbital width and contained 3 to 34 times in length of
head; mouth extending to below anterior border of eye; cheek naked; a few
deciduous scales on opercle; nasal, frontal, preeorbital, suborbital, preeopercular, and
mandibular bones cavernous, with large cavities covered with thin skin and separated
by narrow septa. Gill-rakers short, 17 on lower part of anterior arch. Dorsal
X-XII 9-11; spines increasing in length to the 6th or 7th, which measures 4 length
of head; soft rays scarcely longer. Pectoral very pointed, as long as or a little longer
than the head. Ventral reaching origin of anal. Anal III 7-8; third spine nearly
as long as dorsals. Caudal deeply notched, crescentic. Caudal peduncle nearly twice

as long as deep. Scales 30-32 2 lat. 1. 5-14. Silvery, brownish above; a large,
rounded, black spot on posterior third of spinous part of dorsal, rarely followed by a
second.

Total length 120 millim.

Several specimens from the Usambura market.

‘ As in Hetodus the inner rays of the ventral are the longest.

156 MR. G. A. BOULENGER ON A COLLECTION

Closely allied to the preceding species. Differing in the longer dorsal spines. fewer
anal rays, and in the presence of a black spot on the dorsal.

I have been able to examine the skeleton of this species. The occipital crest is
strong and extends to between the orbits; a more feeble parietal crest. The median
pharyngeal teeth have rounded spheroidal crowns. 12 praecaudal and 19 caudal
vertebrae; the last praecaudal vertebra bears a hemal arch. It is not without interest
to point out the parallelism that can be drawn in comparing Trematocara (with its
excessively developed cephalic cavities) with the perch-like Cichla on the one hand and
Acerina and Perca, among Percide, on the other :—

Trematocara: Vert. 12+19=81. Acerina: Vert. 15+19=34.
Cichla : Vert. 18-194 17=35-36. Perca: Vert. 21-22+19-21=41-42.

‘The two genera in each family standing very nearly in the same relation to each
other both as regards the skull and the vertebral column.

35. TELMATOCHROMIS TEMPORALIS Blgr.

Kibwesi.

GEPHYROCHROMIS.
Bouleng. Ann. & Mag. N. H. (7) vil. 1901, p. 4.

A band of very small tricuspid teeth in each jaw, with an outer series of larger conical
teeth bent inwards; lateral teeth conical. Maxillary exposed. Body moderately
elongate; scales cycloid; two lateral lines. Dorsal with 17 spines, anal with 3.

Differs from Paratilapia as Telmatochromis differs from Lanprologus.

36. GEPHYROCHROMIS MooRIT. (Plate XX. figs. 1, 1a.)
Bouleng. J. ¢.

Depth of body equal to length of head, 3 times in total length. Snout with slightly
convex upper profile, as long as the diameter of the eye, which is contained 33 times
in length of head and equals interocular width ; maxillary extending to between nostril
and eye; 56 conical teeth, with brown points, in the upper jaw; 3 series of scales on
the cheek ; larger scales on the opercle. Gill-rakers short, 18 on lower part of anterior
arch. Dorsal XVII 8; spines increasing in length to the last, which measures 3 length
of head and 2 longest soft rays. Pectoral nearly as long as head. Ventral produced
into a long filament extending beyond origin of anal. Anal III 7; third spine longest,
a little shorter than last dorsal spine. Caudal rounded. Caudal peduncle as long as

deep. Scales 30 29 latenle = Uniform pale brown.
Total length 120 millim.

A single specimen from the north end of Lake Tanganyika.

7. SIMOCHROMIS DIAGRAMMA Gthr.

3
Msambu.

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 157

538. TILapia niLotica L.

This Nile species, which is also found in Syria, in the Senegal, Gambia, and Niger,
has been found in Lake Kivu.

39. ‘TILAPIA BURTONI Gthr.

Discovered at Ujiji by Mr. Coode Hore, this species has since been found at Albert-
ville by Capt. Heeq. Mr. Moore obtained specimens in Lake Kivu.

40. 'TrLaPIA DARDENNII Bler.

Kibwesi and Kalambo. Grows to a length of 230 millim.

41. 'Trnapia LABIATA Bley.
Kibwesi.

42. TILAPIA PLEUROTHNIA. (Plate XVIII. fig. 4.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 4.

Depth of body 23 to 3 times in total length, length of head 3 to 34 times. Snout
with the profile descending in a straight line, as long as the diameter of the eye, which
is contained 53 to 34 times in length of head, and exceeds a little interocular width ;
mouth small, its width half, or a little more than half, that of the head, extending to
below nostril or between nostril and eye; teeth very small, in 3 series, outer bicuspid ;
3 or 4 series of scales on the cheek. Gill-rakers short, 10 to 12 on lower part of
anterior arch. Dorsal XV-XVIII 11-12; last spine longest, a little less than half
length of head; longest soft rays 3 length of head. Pectoral pointed, a little shorter
than the head, not quite reaching origin of anal. Anal III 8-10; third spine a little

shorter than last dorsai spine. Caudal deeply notched, crescentic. Caudal peduncle

1d as long as deep. Scales very thin, without denticulation, 82-35 TEE lat. 1. aoe
Pale brown above, white beneath; a blackish lateral stripe, from the opercle to the
caudal ; fins greyish ; small, round, white spots on soft dorsal and caudal.

Total length 110 millim.

Several specimens from the north end of Lake Tanganyika and from the mouth of
the Rusisi River.

43, ‘TILAPIA TREMATOCEPHALA. (Plate XIX. fig. 6.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 4.

Depth of body equal to length of head, 34 times in total length. Snout with slightly
convex upper profile, a little shorter than diameter of eye, which is contained 3 times
in length of head and exceeds interocular width; mouth small, its width half that of
head, extending to between nostril and eye; teeth very small, in 2 rows, outer bicuspid ;
3 series of scales on the cheek; large scales on the opercle; orifices of sensory canals

158 MR. G. A. BOULENGER ON A COLLECTION

on head remarkably large. Géill-rakers rather short, 13 on lower part of anterior arch.
Dorsal XVI 11; last spine longest, half length of head; longest soft rays produced
into filaments, half length of head. Pectoral pointed, # length of head, not reaching
origin of anal. Ventral produced into a filament, extending beyond origin of anal.
Anal III 9; third spine as long as and stronger than last dorsal spine ; some of the
soft rays produced into filaments, as in the dorsal. Caudal deeply emarginate. Caudal
peduncle 14 as long as deep. Scales very thin, without denticulation, 40 = lat. 1. oe
Brownish ; dorsal and caudal greyish ; ventrals and anal black, latter edged with white.

Total length 90 millim.
A single specimen from the north end of Lake Tanganyika.

44, Trnapia Boops. (Plate XIX. fig. 5.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 5.

Depth of body equal to length of head, 34 to 33 times in total Jength. Snout with
strongly convex upper profile, shorter than diameter of eye, which is 24 times in length
of head, and exceeds a little interocular width; mouth 2 width of head, subinferior,
not extending quite to below anterior border of eye; teeth very small, tricuspid, in
3 rows; 2 or 3 series of scales on the cheek ; large scales on the opercle. Gill-rakers
short, 13 on lower part of anterior arch. Dorsal XII-XIII 14; spines slender, equal
from the 7th, which measures nearly 4 length of head; soft rays scarcely longer.
Pectoral pointed, as long as head, reaching origin of anal. Ventral produced into a
filament, extending beyond origin of anal. Anal III 8-9; third spine as long as and
stronger than longest dorsal spines. Caudal deeply emarginate, crescentic. Caudal
peduncle nearly twice as long as deep. Scales thin, without denticulation, 39-40 — :

lat. 1. a Brown above, white beneath ; a blackish opercular spot.

Total length 90 millim.
Two specimens from Msambu.

45. TILAPIA MICROLEPIS Blegr.

Kalambo.

This species grows to a length of 440 millim. Such large specimens lose the
secondary cusp of the teeth, and might therefore be referred to the genus Paratilapia.

46. PETROCHROMIS TANGANICA.
Chromis tanganice Ginth. Proc. Zool. Soe, 1893, p. 630, fig.

Kalambo.

This species grows to a length of 300 millim. Adult specimens agree entirely in
their dentition with Petrochromis polyodon Blgv.

OF FISHES FROM LAKES TANGANYIKA AND KIVU. 159

ASPROTILAPIA.
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 5.

Teeth small, tricuspid, closely set, in two series in both jaws. Mouth inferior,
transverse; greater part of maxillary bone concealed under the preorbital. Body
elongate, much attenuate in the caudal region, Scales ctenoid; two lateral lines.
Dorsal with 14 spines, anal with 3.

Allied to Tilapia. By the form of the body, the type of this genus recalls Aspro
among the Percide.

47, ASPROTILAPIA LEPTURA. (Plate XX. figs. 2, 2a, 26.)
Bouleng. /. c.

Body rather feebly compressed, its depth 5 times in total length; length of head
4 times in total length. Snout subconical, strongly projecting beyond the mouth, its
length 3 that of the head; eye very large, its diameter equal to length of snout and
nearly twice interorbital width, 22 times in length of head; width of mouth 2 that of
head; 36 teeth in the outer row of the upper jaw; 3 series of small scales on the
cheek; larger scales on the opercle. Gill-rakers very short, tubercle-like, 15 on lower
part of anterior arch. Dorsal XIV 12; spines slender and subequal, ? length of head ;
soft rays a little longer. Pectoral pointed, a little shorter than head. Ventral reaching
vent. Anal III 8; third spine nearly as long as dorsals. Caudal deeply emarginate,
crescentic. Caudal peduncle 3 times as long as deep. Scales strongly denticulate,
38 a lataell a Brown, darker on the snout and vertex; a blackish opercular spot;
fins greyish.

Total length 95 millim.

A single specimen from Msambu.

48, XENOCHROMIS HECQUI Bler.
Three specimens from Usambura. Grows to a length of 270 millim. D. XVI-XVII
OS ie Ae Min O=NOLeSquie4=—67 — lata lee

30 > * 35-43"

MASTACEMBELIDA.

49, MASTACEMBELUS FRENATUS. (Plate XX. fig. 3.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 5.

Depth of body 13 times in total length, length of head 8% times. Vent equally
distant from end of snout and from caudal fin, separated from head by a space equal
to 32 times length of latter. Snout 3 times length of eye, produced into a trifid
appendage, the length of which exceeds a little diameter of eye; buccal cleft extending
to below anterior border of eye; no preopercular spines. Dorsal and anal confluent

160 ON A COLLECTION OF FISHES FROM LAKES TANGANYIKA AND KIVU.

with caudal, which is short and rounded ; dorsal XVIII 85; anal II 90; first anal spine
very short, second + length of head; distance between first dorsal spine and head
12 times length of latter. Pectoral 7 length of head. Scales extremely small, 22
between origin of dorsal and lateral line. Yellowish brown above, marbled with
darker, yellowish beneath; a dark brown streak on each side of the head, passing
through the eye; two brown bars across the caudal.

Total length 250 millim.

A single specimen, a female full of ova, from the north end of Lake Tanganyika.

50. MAsracEMBELUS TANIATUS. (Plate XX. fig. 4.)
Bouleng. Ann. & Mag. N. H. (7) vii. 1901, p. 6.

Depth of body 13 times in total length, length of head 63 times. Vent equally
distant from head and from caudal fin, separated from head by a space equal to 3 times
length of latter. Snout twice as long as eye, ending in a trifid appendage as long
as latter; buccal cleft extending to below anterior border of eye; no preopercular
spines. Dorsal and anal fins confluent with caudal, which is short and rounded; dorsal
XXXII 85; anal [1 85; first anal spine extremely short, second as long as last dorsal.
Pectoral + length of head. Scales extremely small, 25 between origin of dorsal and
lateral line. Yellowish; a brown lateral band, from the end of the snout, through the
eye, to the caudal region, where it widens, its borders become sinuous, and it bears
some yellow spots.

Total length 105 millim.

A single specimen from the north end of Lake Tanganyika.

PLATE XII.

VOL. XVI.—PART I, No. 4.—October, 1901.

162 FISHES FROM LAKES TANGANYIKA AND KIYVU.

PLATE XII.

Fig. 1. Capoéta tanganice, p. 148. Reduced §.
Fig. 2. Barbus platyrhinus, p. 144. Reduced 3.

‘SNNIHYALV Id SNEUVd'G TE COMINN SIN AG \folb GOI 7o) IE

dur soag uta guy “UAT 38° [ep wusean 7

LA Wb LAX OVOP °C OO"

2) oP ATE X Thon ane ene

5 i chee j

t

L64 FISHES FROM LAKES TANGANYIKA AND KIVU.

PLATE XIII.

Fig. 1. Barbus altianalis, p. 144. Reduced 74.
Fig. 2. ,, tropidolepis, p. 145. Reduced 2.

‘SIARTIOCGIGOUL SNEUVE'G “SIUIWINN ALIN, SOMERSDY/St IL

‘dure soag wraquy

‘UBIL Ja [ep weesig

WY ab [AX 700° O° Yo 7

PLATE XIV. —

*f

166 FISHES FROM LAKES TANGANYIKA AND KIVU.

PLATE XIV.

Fig. 1. Barbus serrifer, p. 145. Reduced $.

Fig. 2. Barilius moorit, p. 146. Reduced 5%.

Bier 2iase a, Me Upper view of head. x 2.

Fig. 3. » tanganice, p. 146. Reduced 7.

Bicasias ames FS Upper view of head. Nat. size.

GATT.

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0. Soo Vt AV.

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3.BARILIUS TANGANICA.

2.BARILIUS MOORII.

1 BARBUS {SERRE BR

Pee ee ae oe tai al

PAD exes

168 FISHES FROM LAKES TANGANYIKA AND KIVU.

PLATE XV.
Chrysichthys brachynema, p. 148, with upper view of head, reduced 3; and dentition
of upper jaw and palate, nat. size.

“WNAUNAHOVUd SAHLHOISAUMHD See eee
dint’ soag 2.19 ypy "i .

AN 0b IW 10°08 99% Pity

:

PEE

170 FISHES FROM LAKES TANGANYIKA AND KIVU.

PLATE XYVT.

Synodontis granulosus, p. 149, with upper and lower views of head.

* duat Sorg uta quip

‘SNSOTONVYHD SILNOGONAS

UML 2 Tap weesyp

WEEE
SSS

LAX feo LAN DVO °Ys GG PPL

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FISHES FROM LAKES TANGANYIKA AND KIVU.

ke

reo |e
gq da

PLATE XVII.

_ 1. Paratilapia stenosoma, p. 151.
. 2. Bathybates fasciatus, p. 153. Reduced 3.

‘SQUVIDSVE SHIVEAHIVaGG VWNOSONTLS VildiV TIvavid 1
-durt' sorg wrequyyL “URL 32 [ep Use1g'¢

TAN 2 TAN 0% 96 7% VAY,

LE) KOWAL

FISHES FROM LAKES TANGANYIKA AND KIVU,

PLATE XVIII.

. Paratilapia vittata, p. 150.

. Xenotilapia ornatipinnis, p. 154.

. Trematocara unimaculatum, p. 155.
. Tilapia pleurotenia, p. 157.

H OF DO Fo

3.

J.Green del.et lith. Mintern Bros imp.

1.PARATILAPIA VITTATA. 2.XENOTILAPIA ORNATIPINNIS.
3.TREMATOCARA UNIMACULATUM. 4.TILAPIA PLEUROTZENIA.

tin a

PEA x

176

FISHES FROM LAKES TANGANYIKA AND KIVU.

PLATE XIX.

Fig. 1. Paratilapia nigripinnis, p. 152.

Fig. 2. 3 aurita, p. 150.
Fig. 3. f calliura, p. 161.
Fig. 4. Eetodus longianalis, p. 154.
Fig. 5. Tilapia boops, p. 158.

Fig. 6, a trematocephala, p. 157.

J.Green del.et hth.

4.1

lL. PARATILAPIA NIGRIPINNIS.

ECTODUS LONGIANALIS.

Qial2) J MORAN:

BOORS:

5), TINEA

PA I

Trams, Loo€. Soo Vl XVI FC. XIX.

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Mantern Bros.imp.

PLATE XX

FISHES FROM LAKES TANGANYIKA AND KIYVU.

PLATE XX.
Fig. 1. Gephyrochromis moorii, p. 156.
Fig. 1 a. 5 PA Open mouth. xX 3.
Fig. 2. Asprotilapia leptura, p. 159.
Fig. 2a. es + Lower view of head. xX 13.
Fig. 2 0. 5 + Mouth. x 4.

Fig. 3. Mastacembelus frenatus, p. 159.
Fig. 4. 9 teniatus, p. 160.

“SOLVINGL IE “SOIVNHUA SNTAANAOVISVIN €
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CONTENTS.

IV. Third Contribution to the Ichthyology of Lake Taganyika.—Report on the
Collection of Fishes made by Mr. J. E. S. Moore in Lakes Tanganyika and
Kivu during his Second Expedition, 1899-1900. By G. A. Boutenesr, F.R.S.,
FG Sx (Plates KIL—XK.) oe Ys RR ee

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V. On new or imperfectly-known Ostracoda, chiefly from a Collection in the Zoological

Museum, Copenhagen. By Guorce Stewarpson Brapy, M.D., LL.D., D.Sc.,
Sh CEL.

Received February 11, read March 19, 1901.
[Puates XXI.-XXYV.]

For the opportunity of examining and describing examples of most of the species
noticed in this paper, I am indebted to the kindness of Drs. Meinert and H. J. Hansen,
of the Zoological Museum at Copenhagen. ‘The specimens were collected by different
observers and in various parts of the world, the particulars as to collectors and habitat
being recorded, so far as they are known to me, under the description of each species.
As a supplement to this report, I have given in tabular form an account of the
Ostracoda contained in a series of tow-net captures made in the North Atlantic by
Dr. George Murray, F.R.S., of the Natural History Museum, South Kensington.
Among these there is a single new species—Conchecissa cucullata—which I have
to thank Dr. Murray for allowing me to describe here. This, indeed, is the only new
species outside of the Copenhagen Collection which is noticed in the present paper.

Family ASTEROPIDA: Brady & Norman.

Genus ASTEROPE Philippi.
ASTEROPE OCULATA, sp. nov. (Plate XXI. figs, 6-13.)

Shell of the male subovate: seen from the side (fig. 6) elliptical, slightly higher
in front than behind, height equal to rather more than half the length; anterior
extremity rounded, antennal notch rather wide and shallow ; posterior extremity not so
fully rounded and bearing two fascicles of hairs, one near the dorsal, the other near the
ventral end; dorsal margin very feebly arched, often with a slight depression behind
the middle, ventral somewhat more distinctly arched: seen from above (fig. 7) the
outline is subcuneate, much wider in front than behind, the greatest width equal to
about one-third of the length ; anterior extremity obtusely pointed, almost mucronate ;
posterior subacute ; lateral margins evenly curved, but flattened and almost rectilinear
in the middle third. Surface of the sheil smooth, whitish or cream-coloured, the large
eyes showing very conspicuously as black circular patches beneath the middle of the
dorsal margin. Length 1:55 mm.

VOL. XVI.—PaRT Iv. No. 1.—April, 1902. 25

180 DR. G. S. BRADY ON NEW OR

The secondary branch of the antenna (fig. 10) is long and slender, and bears a
strongly falcate terminal unguis, which towards its tapering extremity has a sigmoid
twist, and at its base a single stout seta: in some cases, though not always, its outer
margin is rather coarsely crenulated ; the penultimate joint (dactylon) is elongated
and bears three short sete on the distal portion of its inner margin; the second joint
of the mandibular foot (fig. 11) bears a short digitiform process in addition to the
usual setee, but there is no toothed process on the basal joint. Claws of the post-
abdominal lamine (fig. 12) five to eight, varying in number with the age of the
specimen ; margins devoid of spines or pectinations.

Female. Several of the terminal sete of the antennules (fig. 9) are divided apically
into lashes of fine filaments, and the concave margins of the postabdominal ungues
(fig. 13) bear a few minute spines, the intervals between which are very finely
pectinated. Shell shorter and broader than that of the male (fig. 8), greatest height
situated behind the middle and equal to more than two-thirds of its length; anterior
margin narrowly, posterior very broadly rounded; dorsal margin forming a flattened
arch, ventral boldly arcuate. Eye-spot much smaller than in the male and paler in
colour. Length 1 mm.

Hab. Taken in the surface-net at Trincomalee, Ceylon, plentifully; also at Cruz Bay.
These gatherings consisted, with one or two exceptions, entirely of males.

Among a considerable number of specimens one female only could be found, and
this occurred with only one or two males in the collection from Cruz Bay. I figure
here in outline an example of both sexes from this locality. I think there can be little
doubt as to its belonging to the female of this species, although there is a distinct
pectinated armature of the postabdominal ungues which is not visible in the male.
T have, however, already noticed ! in a very closely allied species (A. guadrata) that the
pectination of these ungues is more pronounced in the female than in the opposite sex.
The Trincomalee specimens show a considerable diversity in the number of ungues,
which, I think, may be accounted for by the differences of age.

ASTEROPE LICHENOIDES, sp. nov. (Plate XXIII. figs. 22-24.)

Shell of the male subquadrangular as seen from the side (fig. 22), about twice as
long as broad; anterior extremity irregular, wide and obliquely truncated, the antennal
notch forming a large and deep gap below the middle ; posterior extremity rectangularly
truncate, with a large rounded median prominence; dorsal margin gently convex, with
a shght sinuation in front of the posterior angle, ventral very gently arcuate, with a
slight posterior sinus: seen from above the outline is elongated, quadrate, wider in front
than behind, all the angles very well marked, greatest width equal to half the length

* «On new or imperfectly known Species of Ostracoda, chiefly from New Zealand,” Trans. Zool. Soc.
London, yol. xiy. pt. viii. p. 432 (December 1898).

IMPERFECTLY-KNOWN OSTRACODA. 181

(fig. 25); anterior extremity wide, irregular, truncated, but with a very deep median
sinus, posterior sharply truncated, but concave and fringed with hairs; lateral
margins very irregular, with many sinuations, elevated at the anterior third whence
they slope irregularly towards either extremity; surface of the shell marked through-
out with extremely irregular crested ridges and bosses. Length 4-4 mm. Joints
of the antennee not produced into lateral spines, secondary branch with a narrow,
elongated hand (fig. 24) which is slightly dilated distally and bears a brush of numerous
hairs; terminal claw strongly falcate, bulbous at the base, and slightly so at the apex,
a single stout seta at the base; penultimate joint of the mandibular foot bearing a
digitiform appendage. Postabdominal laminze armed with five long and slender
pectinate claws.
Hab. Lat. 0° 37' N., long. 109° 47’ E. One specimen only.

Genus CycnasteroPe G. S. Brady !.

This genus was founded on a species taken in Madras Harbour, the name being
suggested by the circular outline of the shell, supplemented by certain anatomical
characters. The shape of the shell can no longer be maintained as a generic character,
several other species having been discovered, which with a very different form of shell
combine the other distinctive characters of Cyclasterope. The points which I now
suggest as diagnostic of the genus are the presence of.a digitiform process on the
penultimate joint of the mandibular foot, the profusely setiferous character of the
vermiform limb, each ring of which toward the distal extremity usually supports two or
three sete, and the spinous armature of the joints of the swimming-branch of the
antenna.

CYCLASTEROPE FASCIGERA, sp. nov. (Plate XXI. figs. 20-31.)

Male. Shell seen from the side subovate, slightly higher behind than in front,
greatest height equal to rather more than half the length; left valve overlapping
the right at the antero-dorsal angle, beneath which it is sinuated and forms a slightly
prominent beak (fig. 20); anterior extremity of the right valve evenly rounded, the
antennal notch deep and narrow; posterior extremity wider, rounded off, but strongly
angulated in the middle and again between that point and the dorsum; dorsal margin
almost flat for the greater part of its length, but gently curved behind, ventral forming
a continuous gentle curve: seen from above the outline is elliptical (fig. 21), with
broad, slightly rounded or subtruncate extremities; lateral margins gently and evenly
arcuate, greatest width situated in the middle and equal to half the length. Surface of

1 Trans. Zool. Soc. London, vol. xiv. pt. iii, 1897, p. 85: “ A Supplementary Report on the Crustaceans of
the Group Myodocopa, &c.”
2E2

“

182 DR. G. S. BRADY ON NEW OR

the shell smooth, fringed with rather long hairs on the anterior margin below the beak,
slightly pubescent on the ventral aspect, the posterior extremity with a thick fringe of
long hairs which ends abruptly both above and below. Colour yellowish-white.
Length 6 mm. Sensory appendage of the antennule (fig. 24) large and very densely
setiferous ; joints of the swimming-branch of the antenna (fig. 25) spined on the outer

margin—each spine as long as the following joint—and on the inner margin bearing

fascicles of short hairs; secondary branch (fig. 26) having a long, flexuous claw which
for the greater part of its length is more or less distinctly cross-furrowed and has a
single stout seta near the base; basal joint bearing a few marginal hairs ; second joint
elongated, with sinuous margins and a brush of short sete near the distal end (fig. 26) ;
pectinated process of the mandibular foot rather feebly developed (fig. 27) and having
seven or eight curved apical teeth ; penultimate joint of the limb very densely setose ;
postabdominal lamine of the usual type, each with 5 or 6 strongly pectinated ungues
(fig. 29) ; spines of the larger ungues arranged in sequences, one large and one small
alternately (fig. 50).

Female. Shell seen from the side broadly ovate, greatest height situated behind
the middle and equal to nearly three-fourths of the length, the left valve over-
lapping the right posteriorly (fig. 22); anterior extremity narrowly rounded, beak and
antennal notch well developed, posterior extremity distinctly angulated in the middle;
dorsal and ventral margins very boldly arched, dorsal highest behind the middle,
ventral quite evenly arcuate: seen from above (fig. 25) the outline is subovate, widest
in the middle, about twice as long as broad; anterior extremity produced and sub-
truncate, posterior wider, rounded, the left valve produced much beyond the right ;
lateral margins arcuate, rather deeply sinuated behind the anterior extremity; surface
of the shell smooth, with a few short hairs below the antennal notch. Length
52mm. The “ masticating” process of the mandibular foot (fig. 28) is more largely
developed and more strongly serrated than in the male; the claws of the postabdominal
lamine are regularly spined (fig. 31), and the terminal joints of the mandibular foot are
destitute of the setose covering which is found in the male.

Hab. Sourabaya (Java), several specimens, ¢ 2; Chiribon (Java), 43 fathoms, one
specimen, ¢; Madeira, one specimen, ¢.

The fact of male and female specimens being found together in the same gathering
leads to the supposition that both belong to the same species, though the remarkable
differences in the shape of the shell may be thought to throw some doubt on that view
of the matter. Pending further observation the two forms may be considered identical.
The antennal sete of this species are often much encumbered, or even glued together
by crystalline calcareous concretions similar to those which I have already described
and figured as occurring in Philomedes sculpta }.

* “On new or imperfectly-known Ostracoda,” tom. cit. p. 435.

IMPERFECTLY-KNOWN OSTRACODA. 183

CYCLASTEROPE BREVIS (G. W. Miiller). (Plate XXIV. figs. 16-22.)

Asterope brevis G. W. Miiller, “ Neue Cypridiniden,” Zoologisch. Jahrbiich. vol. v. p. 239, pl. xxv.
fig. 10, pl. xxvi. fig. 7, pl. xxvii. figs. 7-10, 15, 16.

Shell of the female seen from the side (fig. 16) almost circular, the length being only
about one-seventh longer than the width, antennal notch situated slightly below the
middle of the somewhat narrowed anterior extremity; posterior extremity boldly rounded,
as is also the ventral margin; dorsal margin well arched, but flatter than the ventral ;
the right valve is slightly overlapped by the left throughout its entire circumference:
seen from above the outline is elongated, ovate, nearly twice as long as broad,
extremities obtusely rounded, rather narrower in front than behind. Shell-surface
smooth; colour brown. Length 3°3 mm. The fifth joint of the antennule (fig. 17)
has five marginal papilliform humps; the external margins of the antennal joints
(fig. 18) are produced into very large, stout spines; the principal swimming-sete are
profusely ciliated and have, at intervals of five or six rings throughout the greater
part of their length, delicate marginal spines (fig. 19) ; secondary branch of the antennz
(fig. 20) two-jointed, the first joint bearing five or six marginal hairs, the last a
single long, ringed seta. Postabdominal lamine armed with four finely pectinated
claws (fig. 22).

Hab. St. Thomas, West Indies. Very few specimens, all females.

The male is unknown; the one female specimen described by Miiller was taken off
the coast of South America (Pernambuco): in all essential respects it seems to agree
with those here noticed.

CYCLASTEROPE SIMILIS, sp. nov. (Plate XXIII. figs. 25-29.)

Shell of the female, seen from the side, subelliptical, height equal to nearly two-
thirds of the length (fig. 25); antennal notch rather wide and shallow, situated in the
middle of the evenly rounded anterior extremity; posterior extremity as wide as the
anterior, evenly rounded; dorsal margin almost rectilinear for the greater part of its
length, ventral moderately arcuate ; both extremities fringed with short hairs; surface
smooth. Length 5mm. Penultimate joint of the antennule (fig. 26) having a single
large papilliform hump and a few fine marginal hairs: outer margins of the antennal
joints, except the first, produced into long stout spines (tig. 27), first swimming-seta
short and plumose, none of the sete bearing marginal spines; secondary branch
(fig. 28) indistinctly three-jointed, the last joint bearing a single ringed seta, the first
five marginal hairs. Male unknown.

Hab. One specimen only, from a depth of 8 fathoms in Java Sound.

‘his species approaches Asterope brevis G. W. Miller in the single hump of the
fifth antennular joint, but differs widely in the shape of the shell and the characters of
the antennal swimming-sete.

184 DR. G. 8. BRADY ON NEW OR

Family CYPRIDINID Baird.
Genus CypripiIna M.-Edwards.

CYPRIDINA GRANULOSA, sp. nov. (Plate XXI. figs. 82-34.)

Shell of the female, seen from the side, elongated, subovate; height equal to two-
thirds of the length (fig. 52) ; anterior extremity rounded, with a sharp downward-
pointing beak; antennal notch near the middle line, rather wide and deep ; posterior
extremity narrowly rounded; dorsal margin evenly arched, highest in the middle,
sloping steeply toward the posterior extremity; ventral margin gently arcuate: seen
from above (fig. 33) the outline is narrowly ovate, twice as long as broad, greatest
width in the middle. ‘lhe shell is thin, membranous, and granular in appearance.
Length 1-95 mm. Male unknown.

One specimen cnly, Memorandum of locality lost.

CYPRIDINA FOVEOLATA, sp. nov. (Plate XXII. figs. 15-19.)

Shell of the female, seen from the side (fig. 15), elongated, ovate, produced behind
into an obtuse median beak; greatest width situated in the middle and equal to two-
thirds of the length; anterior extremity rounded, beak not prominent, antennal notch
small and shallow; posterior extremity narrow, forming an obtuse subtriangular beak ;
dorsal and ventral margins boldly and evenly arched, the ventral the more arcuate of the
two and forming a continuous curve throughout, the dorsal sinuated in front of the
posterior beak: seen from above (fig. 16) the outline is ovate, widest in the middle,
width equal to half the length, very narrowly rounded in front, subacuminate behind.
Shell thin, smooth, almost membranous, marked throughout with small, closely-set
circular impressions. Length 3°5 mm.

The soft parts present no abnormal characters ; caudal lamine (fig. 19) with four
slightly curved, pectinated ungues.

Hab. China Sea. One specimen only.

CYPRIDINA INSOLITA, sp. nov. (Plate XXII. figs. 11-14.)

Shell of the female broadly ovate, tumid; seen from the side subovate, narrow in
front, broadly and obliquely truncated behind, width equal to three-fourths of the
length (fig. 11); anterior extremity narrow, rounded, beak short and sharp, antennal
notch narrow and moderately deep; posterior extremity very iregularly sinuous;
dorsal and ventral angles strongly marked, dorsal margin gently arcuate, ventral very
boldly convex: seen from above (fig. 12) the outline is broadly ovate, widest in the
middle, both extremities broadly rounded, width nearly equal to the height. Surface

IMPERFECTLY-KNOWN OSTRACODA. 185

of the shell marked with distant circular pittings, in the intervals of which are
minute puncta. Length 37 mm. The antennal swimming-sete, excepting the first,
are densely plumose and without spines, the first much smaller, imperfectly jointed,
non-plumose, and bearing several short but sharp marginal spines; secondary branch
of the antenna simple, two-jointed, and bearing a long terminal seta (fig. 13). The
vermiform limb has a simple terminal claw (fig. 14), beneath which is a large quadrate
gap, and following this a still larger unjointed space beyond the ringed portion of
the limb.
Hab. Java Sound, in a depth of 8 fathoms. One female only.

Genus Pyrocypris G. W. Miiller.
(= Lupathistoma G. 8. Brady.)

Pyrocypris AMERICANA G. W. Miiller. (Plate XXI. figs. 14-19.)
Pyrocypris americana G. W. Miiller, Neue Cypridiniden, tom. cit. p. 233, pl. xxv. fig. 3.

Shell, seen from the side, elongated, obliquely subquadrate, about twice as long as
broad (fig. 14); anterior extremity narrow, beak short, obtusely pointed in front,
acutely below, antennal notch small and narrow; posterior extremity produced into a
prominent rounded beak ; dorsal margin gently arcuate, sloping steeply behind, ventral
boldly rounded in front, thence gently curved throughout its whole length; shell
smooth, thin, chitinous. Length 2 mm. Secondary branch of the antenna (fig. 16)
reduced to a fascicle of five short sete; mandibular foot nearly as in Cypridina (fig. 17),
bearing an ovate setiferous lobe and digitiform process ; vermiform limb armed at the
free extremity with three slender curved claw-like sete (fig. 18), caudal lamin
(fig. 19) having four strong pectinated ungues and three shorter spine-like setze.
The first long seta of the antennule is dilated bulbously at the base (fig. 15), and bears
a short tubular (?) barb (a) on the distal side of the bulb. The labial papille
(phosphorescent organs of Miiller) are not unlike those of P. chierchie (Eupathistoma
natans Brady), which have been previously figured and described by me as
sense-organs.

I do not fully understand the nature of the bulbous enlargement at the base of the
antennular sete, but it has an appearance somewhat similar to the poison-glands of the
Cytheride, and I would suggest that it may have a similar function, the barb-like
appendage being its efferent duct.

Taken by the ‘ Galathea’ Expedition, Sept. 10th, 1875.

Specimens from this collection have been identified by Dr. G. W. Miiier as
belonging to Pyrocypris americana, which species was described from specimens taken
off the west coast of Central America.

186 DR. G. S. BRADY ON NEW OR

Pyrocypris curprcuim G. W. Miiller.

Pyrocypris chierchie G. W. Miiller, tom. cit. p. 232, pl. xxv. figs. Sa (A UG 2S.40 sifech WPA, le)
pl. xxvii. figs. 1, 2, 13, 14, 18, 24, 37.
Eupathistoma natans G. 8. Brady, tom. cit. p. 437, pl. xliv. figs. 21-26.

Hah. Bay of Bengal: ‘ Galathea’ Expedition, July 10th & J1th, 1896.

This and other species of Pyrocypris occur in immense numbers in tropical seas,
and seem to contribute a very large share to the phosphorescence of those regions.
This has been noticed by many authors. Dr. G. W. Miiller notes that of P. chierchie
as many as twenty thousand individuals were taken in a single haul, and of P. revilli
fifteen thousand, and he attributes their light-producing faculty to the labial papillz
which, so far as at present appears, are peculiar to this genus.

Genus PuitomepEs Lilljeborg.

Puttomeprs sorpipa G. W. Miiller. (Plate XXIV. figs. 23-26.)

Philomedes sordida G. W. Miller, tom. cit. p. 237, pl. xxv. fig. 17, pl. xxvi. fig. 17, pl. xxvii.
figs. 28, 33.

Shell of the male (fig. 23), seen from the side, oblong-ovate, widest in the middle,
scarcely twice as long as broad ; anterior extremity narrow, rounded, without a beak,
antennal notch forming a wide and shallow sinus quite on the ventral margin ;
posterior extremity broader, well rounded ; dorsal margin well arched, forming an even
curve throughout its entire length; ventral margin boldly arcuate from the antennal
notch to the posterior extremity: margins of the valves fringed at both extremities
with numerous closely-set sete, which extend in front on to the ventral and behind on
to the dorsal surface; right valve slightly overlapping the left in front: shell chitinons,
its surface marked with small closely-set subrotund pittings. Length 1:55 mm.

The anatomy of the animal agrees generally with Philomedes, but the following
characteristic points may be noted:—The secondary branch of the antenna (fig. 24)
is extremely slender, the penultimate joint linear and bearing on its inner margin
two short sete, terminal joint dilated at the base, strongly curved and blunt, a long
seta at the base and a shortone near the extremity; vermiform limb bearing very
few sete, armed at the distal end with three small claws at one side of the gape and
two on the other (fig. 25); postabdominal lamine (fig. 26) with two large simple
basally-pectinated terminal ungues, followed twice by sequences of a short and a long
unguis, and finally three small sete.

Hab. Cruz Bay. Three specimens, ¢. Mliiller’s specimens were all females and
were taken off the north of Japan.

PHILOMEDES DEBILIS, sp. nov. (Plate XXI. figs. 1-5.)

Shell of the ma/e, seen from the side, ovate, widest in the middle, width equal to
nearly two-thirds of the length (fig. 1); anterior extremity narrow, rounded, without a

IMPERFECTLY-KNOWN OSTRACODA, 187

beak, but with a shallow antennal notch just in front of the ventral margin, posterior
margin broadly and evenly rounded; dorsal and ventral margins boldly and evenly
arcuate: seen from above the outline (Pl. XXI. fig. 2) is regularly ovate, twice as long
as broad, greatest width in the middle. Shell chitinous, smooth, its edges above and
below the antennal notch bordered with a thin chitinous flange, within which is a
nodulated crest having an appearance somewhat like the corneal lenses of an insect-eye
(fig. 3). Length 1mm. The antenne are of the normal type, but with the first joint
smaller than usual (fig. 4); caudal lamine (fig. 5) narrow; at the proximal end three
small ungues, followed by one larger, then three small and one larger, one small and
two very much larger terminal claws.
Hab. Trincomali, Ceylon. Three specimens, ¢.

Genus CyPRIDINODES, gen. nov.

Like Cypridina, except as to the three pairs of maxille. The first pair (Pl. XXII.
fig. 26) form a simple, elongated, triarticulate limb, which bears at its distal extremity
several strongly pectinated claws and setz ; to the basal joint is attached a small single-
jointed trisetose palp. The second maxilla (fig. 27) is in general build like that of
Philomedes or Cypridina, but the principal masticating processes are armed with blunt
nodular marginal teeth (fig. 27, a-c); third maxilla (fig. 28) without the hatchet-
shaped lobe of Cypridina, which is replaced by a digitiform prolongation, retaining,
however, something of the hatchet-shape.

CYPRIDINODES FAVUS, sp. nov. (Plate XXII. figs. 20-31.)

Shell of the female seen from the side (fig. 20) broadly subovate, width equal to
nearly three-fourths of the length; anterior extremity rectangularly truncated, posterior
produced into a broad, truncated, subconical beak; dorsal and ventral margins boldly
arched: seen from above (fig. 21) the outline is irregularly hexagonal, greatest width
in the middle, and equal to two-thirds of the length ; extremities wide and truncated,
the anterior broadly mucronate, the posterior irregularly notched; lateral margins
deeply furrowed in the middle, thence sloping steeply in a sinuous line to each
extremity. Surface of the valves coarsely pitted with deep irregularly-angular
impressions, and raised into two subcentral mammilliform elevations, between which
is a deep transverse furrow ; a little within, and parallel with, the ventral margins the
central portion of the valve is bounded by an irregular jagged crest; the left valve is
overlapped by the right in front and on the dorsal aspect. Length 3 mm. ‘The
penultimate joint of the antennule (fig. 22) has at its distal end a stout ringed seta,
which bears a series of about twelve stout lash-like sete arranged in a secund manner
along its inner edge; two of the principal sete of the terminal joint are dilated at
their bases, forming a pair of globular or subglobular sacs ; first seta of the swimming-

VOL. XVI.—PaART lV. No. 2.—April, 1902. 2 F

188 DR. G. S. BRADY ON NEW OR

branch of the antenna (fig. 23) non-plumose, but bearing a series of about twelve

lanceolate spines; secondary branch of the antenna three-jointed, with one terminal

seta aid one plumose seta on the first joint; mandibles as in Cypridina; caudal

lamin armed with six strong curved ungues, the first of which is strongly pectinated.
The locality of this species appears to have been lost.

Genus CopoNnocera, gen. nov, !

(? Heterodesmus Brady ”.)

Shell flat dorsally, very convex ventrally, with a well-marked anterior beak and
antennal notch, and at the posterior.extremity a wide rounded protuberance (Pl. XXII.
fig. 1), The antennules bear at their apices, in addition to the ordinary sensory sete,
two shorter filaments (figs. 8, 9), which are dilated in the middle and divided distally
into two branches, one of which is bifurcate, the other shorter and terminating in a
bunch of six bell-shaped suctorial disks; secondary branch of the antenna (fig. 3)
provided with a very large and powerfully muscular hand, the claw of which is
marginally nodulated; mouth-organs as in Philomedes; postabdominal lamin (fig. 7)
with only three ungues.

CoDONOCERA CRUENTA, sp. nov. (Plate XXII. figs. 1-10.)

Shell of the male, seen from the side (fig. 1), subquadrate, height equal to two-thirds
of the length; anterior extremity rounded both above and below the uotch; beak
short and sharp; antennal notch moderately deep; posterior extremity wide, obliquely
subtruncate, with a wide angular notch in the middle; dorsal margin straight, sloping
steeply in front from its angulated extremity, rounded off posteriorly ; ventral margin
very boldly and evenly arcuate: seen from above (fig. 2) regularly ovate, widest in the
middle, twice as long as broad; extremities subacuminate. Shell smooth, chitinous,
pale-coloured, irregularly marked with black, stellate pigment-patches of various size,
and with some pale clouded streaks near the centre of the valves. Length 2°38 mm.
First swimming-seta of the antenna (fig. 3) short, non-plumose and spinous on the
outer margin; secondary branch (fig. 3) very large, the hand armed with two strong
spine-like sete, which oppose the terminal claw; claw sigmoidally bent, nodulated on
its inner edge and round the base of the outer edge; vermiform limb very sparingly
setiferous, its apex armed with four small spines on the outer and one on the inner

1 ~wdwy, a bell; Képas, a horn.
2 G, S. Brady: “On new or imperfectly-known Species of Marine Ostracoda,” Trans. Zool. Soc. Lond.

vol. vy. p. 387.

IMPERFECTLY-KNOWN OSTRACODA. 189

side (fig. 6) ; copulatory organs large and massive (fig. 20), the vasa deferentia very
distinct and wide. Postabdominal lamine (fig. 7) short, with three very slightly
curved, unequal, feebly pectinated claws. All the appendages of the animal are
symmetrically blotched here and there with patches of red pigment.

Ilab. Pulo Penang. One specimen, g.

The genus Heterodesmus, instituted many years ago for the reception of a single
species taken in the China Sea, has in general form, though not in minor characters, a
very marked resemblance to this species. It was described, however, from a single
dried shell, from which the soft parts of the animal had almost entirely disappeared,
so that it is impossible to say whether or no it might be properly referatle to the
genus here described.

Family SARSIELLIDZ Brady & Norman.

Genus SARSIELLA Norman.

SARSIELLA (?) ORNITHOIDES, sp. nov. (Plate XXIII. figs. 16-21.)

Shell of the female, seen from the side, elongated, muclr produced both before and
behind (fig. 16), fully twice as long as broad; anterior extremity produced into a
subquadrate prominence which is about one-half the width of the valve and sub-
truncate or only slightly rounded in front, posterior forming a truncated conical
protuberance; dorsal margin flattened, irregularly sinuated throughout; ventral margin
boldly arcuate in the middle, sloping almost in a right line to the posterior extremity
and forming a deep sinus beneath the anterior prominence; seen from above (fig. 17)
elongated, subovate, more than twice as long as broad, with broadly mucronate
prominences before and behind. Surface of the shell smooth, with a slight median
longitudinal depression. Length 1 mm. Swimming-sete of the antenne very faintly
plumose, but bearing fine marginal spines (fig. 19); secondary brauch rudimentary,
simple, digitiform, grannlated (fig. 19). Postabdominal lamine with two strong but
almost straight toothless spines (fig. 21) and a few small sete anteriorly.

Hab. Trincomalee, Ceylon. One specimen only.

The characters of the caudal laminz seem to associate this species with Sarsiella,
the shell also bearing some distant resemblance to that genus, but. its position here

must be regarded as purely provisional.

le)
ty
Lo

190 DR. G. S. BRADY ON NEW OR

Family HALOCYPRID Claus.

Genus Concuacta Dana.

CoNCH@CIA SPINIROSTRIS Claus.
Conchecia spinirostris Claus, Die Halocypriden des atlantischen Oceans und Mittelmeeres, p. 56,
pl. i. figs. 1-12.
A few specimens of both sexes from lat. 26° 15' N., long. 29° 56’ W.; lat. 22° 20'N.,
long. 27° 0! W.; “ Patellaria Syd overfladen” (Pacific), surface-net (females only).

CoNCHGCIA STRIATA Claus.

Conchecia striata Claus, loc. cit. p. 62, pl. vill. figs. 1-6.

Taken in lat. 22° 55’ N., long. 29° 19’ W.

Genus Evconcuacta G. W. Miiller.

Shell as in Conchecia: groups of glands placed symmetrically at the postero-dorsal
angles of the valves; frontal tentacle long, slender, and unjointed; antennule with
three nearly equally long joints, the second of which is without sete, while the third
(coalescent third and fourth) instead of two sensory filaments bears a brush of about
twenty sete; last joint short, bearing one short and two long sete, none of which
are toothed. Secondary branch of the antenna with a slightly dilated basal joint,
without papillary processes and with slender sete; the three sete of the last joint not
of a sensory kind, but attached to the knee-like angle of the claw are two shorter sete.
Masticatory-plate of the mandible without sete, the teeth numerous, short and stout.
Last joint of the penultimate limb bearing sete which are as long as the limb itself.
Antennule of the female short, simple, two-jointed, bearing a terminal brush of sete
similar to that of the male.

This generic definition, so far as it applies to the male, is adapted from G. W. Miiller
(loc. cit.).

The only species is

Evconcnacra cHIERcHIa G. W. Miiller. (Plate XXIV. figs. 9-15.)
Euconchecia chierchie G. W. Miller, loc. cit. p. 277, pl. xxvii. figs. 1-10.

Shell, seen from the side, subquadrangular, elongated ; twice as long as broad
(fig. 9), produced in front into a prominent, curved beak, beneath which is a large
sinus; posterior extremity subtruncate, rounded-off ventrally, and produced into a
short spine (right valve only) dorsally ; dorsal margin almost straight, or only slightly
sinuated, ventral boldly arcuate. Length of the ma/e 1:1 mm.; of the female -85 mm.

IMPERFECTLY-KNOWN OSTRACODA. 191

The secondary branch of the antenna in the female (fig. 12) is two-jointed, the last
joint short and bearing two long, but unequal sete; that of the left side in the male is
almost exactly similar, but on the right side bears as usual a very acutely angular hook-
like claw (fig. 13). The ungues of the caudal lamina are five in number, very slender,
and scarcely at all curved (fig. 15). The copulatory organ in the male is unusually
broad and short (fig. 15).

Hab. The gathering here noticed consists of about equal numbers of males and
females, and was taken at Cruz Bay. Miiller’s specimens, five in number and all males,
were from the coast of Brazil.

Genus Concuacissa Claus.

CoNCHG@CISSA CUCULLATA, sp. nov. (Plate XXIV. figs. 1-8.)

Shell, seen from the side, oblong, much more than twice as long as broad ; greatest
width near the hinder extremity (fig. 1); anterior extremity forming a narrow, sub-
cuneate, or hood-shaped prominence which is very acute at its apex, curvate on its
ventral, and perfectly straight on its dorsal margin, a shallow notch on its posterior
termination, from which point the ventral margin of the valve becomes boldly arcuate as
far as the posterior extremity, which is well rounded below but obtusely rounded at the
dorsal angle; dorsal margin almost perfectly straight, but armed behind with a few
slender, backward-pointed spines ; postero-dorsal angle of the left valve (figs. 1 & 2)
produced into a very long spine-like process, below which is a broad curved sinus
terminated by a short papilliform process, beyond which the curve of the ventral
margin as far as the middle of its course is finely serrated; dorsal angie of the right
valve rounded and spineless, but bearing a mammillated process like that of the opposite
valve; there are groups of gland-cells connected with these processes and with the
dorsal spine, and similar, but smaller, cells are continued for a considerable distance
round the margin of the valves: seen from below the shell is elongated, subovate,
widest in the middle, three times as long as broad, tapering nearly to the extremities,
which are sharply mucronate. Surface of the valves sculptured with regular, sub-
parallel wavy striz, from which are given off numerous delicate cross strie; the course
of many of the larger striew, especially on the posterior and ventral portions of the
valves, being marked by small irregularly-placed circular pits or areole. The chewing-
plates of the mandible (fig. 6) are armed with unusually short and blunt teeth, and are
only sparingly setiferous. Antennule of the female (fig. 3) bearing five (or six 2) equal
terminal sete, and one very short plumose hair; frontal tentacle very slender, linear,
and sharply pointed, and having a sharp needle-like hair alongside of it; secondary
branch of the antenna of the female (fig. 5) short, ovate, bearing two short, spine-like
sete and a brush of five sensory filaments of moderate and equal length, that of the

[92 DR, G. 8. BRADY ON NEW OR

male (fig. 4) having four sensory sete and a strongly falcate claw. Postabdominal
lamin armed with eight slender, curved, slightly pectinate claws, which increase
progressively in length from before backward. ‘The crop is excessively stout and
muscular (fig. 8). Length 2°6 mm.

IIab. This appears to be a rather scarce species: the few specimens which were
noticed occurred in plankton gatherings from the North Alantic, for the opportunity
of examining which I am indebted to Dr. George Murray, F.R.S., of the Natural
History Museum, South Kensington. ‘The following are the localities :—Lat. 52° 27'°6
N., long. 15° 40’ W., 1570 fathoms (1 specimen) ; lat. 52° 18'-1 N., long. 15° 53’9 W.,
950 fathoms (1 specimen), 500 fathoms (1 specimen); lat. 52° 27'6 N., long. 15° 40’ W.,
1170 fathoms (1 specimen); Jat. 52° 18’1 N., long. 15° 53’9 W., 1070 fathoms
(3 specimens).

Only ore male specimen was seen, and I failed to find the antennule, which had
probably been detached in the process of capture.

The reference to the genus Conchecissa must be taken as provisional only, as some
important characters could not be clearly made out from the material at my command.

Family CYPRIDID.
Genus Crypris Miller.

Cypris VIRENS (Jurine). (Plate XXIII. fig. 8.)

Several specimens collected by Dr. Meinert at Bona, Algiers, one of which is here
figured, appear to be referable to C. virens, although differing somewhat from typical
examples in the shorter and more tumid form of the shell. The soft parts conform
accurately to the type.

CYPRIS FLEXILIS, sp. nov. (Plate XXIII. figs. 11-15.)

Shell, seen from the side, oblong, subreniform, about twice as long as broad (fig. 11) ;
anterior extremity moderately rounded, posterior rounded off above, obscurely angular
below owing to a production of the left valve; dorsal margin forming a flattened arch,
ventral very slightly sinuated in the middle. Shell extremely thin, flexible, and almost
transparent. Length 4 mm. The swimming-sete of the antenne (fig. 12) reach
scarcely to the apices of the terminal claws; principal ungues of the first pair of
maxille finely ciliated, but without marginal spines; terminal claw of the first pair of
feet (fig. 14) extremely long and slender, equal in length to the four preceding joints ;
caudal lamine very long and slender, their posterior margins very finely (almost
imperceptibly) ciliated; the terminal sete, two apical and two marginal, crowded
together at the distal extremity.
Hab. A few specimens taken at St. Croix, West Indies.

IMPERFECTLY-KNOWN OSTRACODA. 195

CYPRIS LATEVIRENS, sp. nov. (Plate XXIII. figs. 3-5.)

Shell, seen from the side, elongated, subovate, highest in the middle ; height slightly
exceeding one-half of the length (fig. 3); extremities rounded, the anterior broad and
rather flattened, the posterior narrower; dorsal margin evenly arcuate, highest in the
middle where it is almost angular, ventral margin slightly sinuated in the middle:
seen from above (fig. 4) ovate, twice as long as broad, widest in the middle; anterior
extremity gently tapered and acuminate, posterior acuminate and more abruptly
tapered ; lateral margins evenly arcuate, slightly sinuated behind the anterior extremity.
Surface of the shell smooth, finely hirsute, more particularly round the margins, thin,
semitransparent. Colour very pale green. Length 2°55 mm. The swimming-sete of
the antenn are plumose, and reach to the extremity of the limb; ungues of the first
maxille destitute of marginal spines; postabdominal rami bearing four sete (fig. 5),
two at the apex, one of which is very short and delicate, the other quite half as long as
the ramus itself; the two marginal sete are rather closely approximated and of
moderate size.

Hab. Puerto de St. Maria, near Cadiz.

Genus Cypripopsis Brady.

Cypripopsis acuLEaTA Lilljeborg.

Numerous specimens taken at Puerto de St. Maria, near Cadiz.

CyYPRIDOPSIS MARMORATA, Sp. nov. (Plate XXIII. figs. 1, 2.

Shell, seen from the side, subreniform (fig. 1), widest in the middle, scarcely twice
as long as broad ; extremities well rounded and nearly equal; dorsal margin boldly
arched, ventral very slightly sinuated in the middle: seen from above (fig. 2) broadly

ovate, widest behind the middle, width equal to two-thirds of the length, broadly
rounded posteriorly, obtusely pointed in front. Surface of the valves covered with
small, impressed puncta, and round the margins with fine, closely-set, short hairs ;
marked dorsally, after the manner of @. vidua, with three flexuous, transverse, deeply-
coloured strie. Length 65 mm.

Hab. Bahia.

Subgenus CanpONELLA Claus, Vavra 1.

CANDONELLA VIRESCENS, sp. nov. (Plate XXV. figs. 16-29.)

Shell, seen from the side subreniform, highest in the middle, height equal to nearly
two-thirds of the length (fig. 16); anterior extremity well rounded, posterior narrowly
rounded-off below ; dorsal margin very boldly arcuate, ventral distinctly sinuated in the

1 Vdavra, ‘ Die Siisswasser-Ostracoden Deutsch-Ost-A frikas,’ p. 12.

194 DR. G. 8S. BRADY ON NEW OR

middle: seen from above elongate-ovate (fig. 17), more than twice as long as broad,
lateral margins evenly arcuate, tapering to the extremities, of which the anterior is sub-
acuminate, the posterior narrowly rounded. Surface of the shell smooth, pubescent,
with very fine and rather closely-set short hairs (fig. 19); colour light green. The
ventral margin of the left valve is produced in the centre so as to form an overlapping
flange, which is marked by fine transverse strie (fig. 18). Length 87mm. Swimming-
sete of the antenne (fig. 6) reaching somewhat beyond the apices of the claws; terminal
joint of the antennz narrow, about one-third as long as the preceding joint; second
pair of maxillee (maxillipeds) in the female (fig. 22) digitiform, with a terminal brush of
rather long setee, and bearing an elongated palp which ends in one short and two very long
sete ; in the male the limb is strongly prehensile, on the right side (fig. 24) thick. with
angulated margins, and bearing a very broad, blunt, almost falcate terminal claw, on
the left side (fig. 23) the limb is much narrower, is not marginally angulated, but has
on the inner side a tuft of four or five small hairs and terminates in a sharply bent,
hook-like claw ; terminal unguis of the first pair of feet (fig. 25) stout and strongly
curved; the second foot bears terminally two slender curved claws, one of which is very
short, and a long seta; postabdominal rami (fig. 27) simple, cylindrical, each of them
bearing a long terminal seta and another very minute seta placed a little on the
proximal side of the apex. Copulative organs (fig. 28) elongated, very complex,
ending in a somewhat hatchet-shaped intromittent process (?): on each side of the
postabdominal rami in the female is situated an irregularly shaped laminar process
—spermatheca ? (fig. 29); the testes form two large ovoid coils of delicate spermatic
tubes.

Hab. A gathering from Puerto de St. Maria, near Cadiz, contains numerous examples
of this species.

The genus Cypridopsis proper is distinguished from the subgenus Candonella chiefly
by a much greater tumidity of shell and by the armature and relative lengths of the
last two joints of the antenne—the penultimate joint in Cypridopsis being prolonged as
far, or nearly as far, as the extremity of the last joint, and the claws being slightly
different in the two sexes. Except as a matter of convenience, the differences seem to
me scarcely sufficient to warrant the separation of Candonella as a subgenus.

Genus CypreTTa Vavra!.

Shell as in Cypridopsis. Second pair of legs forcipate. Postabdominal rami as in
Cypris, but much smaller and more slender.
The name Cypretta has been applied by Vavra to this group as a subgenus of

* Vivra, “Siisswasser-Ostracoden Zanzibar’s” (Jahrbuch der Hamburgischen wissenschaftlichen Anstalten
xii. 1895),

IMPERFECTLY-KNOWN OSTRACODA, 195

Cypridopsis. The characters appear to me to be sufficiently distinct to warrant the
adoption of the name as a generic one, and in any case the build of the caudal rami
would seem to ally it more closely with Cypris than with Cypridopsis.

CYPRETTA SARSI, nom. nov. (Plate XXV. figs. 10-15.)

Cypridopsis minna G. O. Sars, Contributions to the Knowledge of the Freshwater Entomostraca of
New Zealand, p. 30, pl. iv. figs. 3 a-d.

Sheli extremely tumid, ovate; seen from the side ovoid, highest in the middle,
height equal to two-thirds of the length (fig. 10), extremities well rounded, dorsal
margin very boldly arcuate, ventral straight, with a slight median sinuation: seen
from above (fig. 11) ovate, widest behind the middle, width equal to three-fourths of
the length, broadly rounded behind, abruptly tapered and subacuminate in front; the
right valve is higher and longer than the left, overlapping it a little dorsally and in
front, also with a protuberant flange in the middle of the ventral margin (fig. 13); the
anterior margin of the valves forms a narrow, produced lip, within and parallel with
which is a series of 12-16 very conspicuous, curved. radiating black bands. connected
at their extremities so as to mark off quadrangular spaces (fig. 12). Surface of the
shell covered with minute circular impressions and fine hairs; on the dorsal aspect
there is a conspicuous, sharply-defined, angular black patch (eye-spot) extending
across the junction of the valves at their anterior third. Colour yellowish-brown ;
some of the larger specimens green. Length ‘77 mm. Extremities of the second pair
of legs produced into nodulated lip-like processes (fig. 14); postabdominal rami very
slender, with two slender claws, the larger of which is nearly as long as the ramus.
The bedy and limbs are marked with a few irregular red blotches.

Hab. St. Thomas, West Indies. Numerous specimens.

These specimens are I think, without doubt, identical with those described by
Professor G. O. Sars under the name of Cypridopsis minna King. ‘They do not,
however, agree with those described by me! under that name, which are considerably
higher in proportion to their length and have a glistening, yellowish, non-pubescent
surface. Sars has, indeed, recognized the difference in outline, and supposes that both
Mr. King’s drawings and my own are probably incorrect owing to the difficulty of
getting a nearly globular shell into accurate lateral or dorsal position; in this, how-
ever, he is mistaken, my drawings, and doubtless Mr. King’s, being quite correct.
Assuming my previous identification of the Australian specimens as C. minna King to
be correct, it becomes necessary to give a new name to the present species. I have
pleasure, therefore, in naming it after Professor G. O. Sars. And though Sars seems
to agree with Mr. King in thinking that the varieties of colour—green, brown, and

1 “Notes on Freshwater Entomostraca from South Australia,” Proceedings of the Zoological Society of
London, 1386, p. 91, pl. x. figs. 1-3.
VOL. XVI.—ParT lv. No. 3.—April, 1902. 2G

196 Dk. G. S. BRADY ON NEW OR

vellow—noted by that author as occurring among his specimens may indicate distinct
species, I am myself scarcely disposed to accept that view, for among the specimens
here described there are many green ones, although the bulk are of the brownish
colour so well described and figured by Professor Sars.

Genus Cyrrinotus G. 8. Brady.

CYPRINOTUS DENTATO-MARGINATUS (Baird). (Plate XXIII. figs. 6, 7.)

Specimens apparently referable to this species were collected by Dr. Meinert at Bona,
Algiers. I give a figure of one of these. It differs somewhat from Dr. Baird’s figure,
being rather more elongated, but has proportions similar to those figured by Prof. G.
. Sars in his paper on ‘‘ Ostracoda and Copepoda raised from dried Australian mud.”
Dr. Baird’s specimens were from Nagpur, India.

CYPRINOTUS FRAGILIS, sp. nov. (Plate XXIII. figs. 9,10; Plate XXV. figs. 57-59.)

Shell, seen from the side (Pl. XXYV. fig. 57), very closely similar in outline to
C. prasina Fischer, but entirely without surface-markings: seen from above (fig. 38)
the posterior extremity is broader and more rounded, the anterior not so distinctly
produced or sinuated; it is also wider in proportion to the length. Shell very thin
and fragile, colourless. Length 1:5 mm.

I figure here some of the soft parts of the animal (Pl. XXIII. figs. 9, 10), which do
not differ from those of the foregoing species.

Hab. Biskra, North Africa; females only (Dr. Metnert).

Genus Canponopsis Vavral.

Antenne destitute of swimming-sete. Mandibles and maxille with much elongated
palps. Maxillipeds (second pair of maxillz) with a rudimentary branchial plate bearing
three or more plumose sete. Posterior margins of the caudal rami without sete.

Vavra’s definition of this genus gives the “fan-plate” of the maxillipeds as bearing
only three plumose sete. None of the few specimens of C. complanata which I have
dissected have had these limbs in a perfect condition, but the remains of at least five
setee were plainly visible in one of them. Inasmuch as in other respects the animals
agree with the typical Candonopsis, it becomes necessary to modify the definition so far
as regards the number of sete.

CANDONOPSIS COMPLANATA, sp. nov. (Plate XXYV. figs. 30-36.)

Shell, seen from the side, elongated, subreniform, more than twice as long as broad
(fig. 50), extremities rounded, equal, dorsal margin forming a flattened curve, almost

» V.ivra, Monographie der Ostracoden Bohmens, 1891: Siisswasser-Ostracoden Zanzibar’s, 1895.

IMPERFECTLY-KNOWN OSTRACODA. UOC

straight in the middle and sloping steeply toward each extremity, ventral straight,
with a slight median sinuation: seen from above (fig. 21) ovate, twice and a half as
long as broad, acuminate in front, rounded behind, widest in the middle; left valve
overlapping the right at both extremities. Surface of the shell smooth, whitish ;
anterior and posterior margins fringed with short hairs. Length 2 mm. ‘The two
principal ungues of the second maxillar segment laterally spined (fig. 32). | Branchial
plate of the maxillipeds (fig. 33) bearing five or six plumose sete; last joint of the
second foot (fig. 34) curved, with two small, but unequal hook-like apical claws, in
front of which is a small adpressed marginal spine, one long apical seta and another of
equal length arising from the middle of the joint; caudal rami with two slightly
curved, pectinate, apical claws and two shorter sete (fig. 55).

Hab. Biskra, North Africa (Dr. Meinert). Females only.

Family BAIRDIIDE Brady & Norman.
Genus Barrpia M‘Coy.

BAIRDIA LONGISETOSA, sp. nov. (Plate XXV. figs. 8, 9.)

Shell, seen from the side, elongated, subrhomboidal, height equal to more than half
the length (fig. 8); anterior extremity broad, obliquely subtruncate, rounded off above
and below, posterior produced to an acute submedian point; dorsal margin boldly
arcuate, highest in the middle, thence sloping with a steep curve backward, more
gently and with a distinct sinuation to the front; ventral margin nearly straight,
rounded off in front, sloping upwards behind; the right valve is overlapped by the left
everywhere, except at the upper part of the anterior extremity, and is much narrower
and more sinuous in outline, its anterior margin slightly crenulated below, ventral
margin armed posteriorly with a series of eight sharp backward-pointing spines ;
margins of the right valve devoid of spines: seen from above (fig. 9) the outline is
regularly ovate, widest in the middle, acuminate behind, but wider in front, about
twice as long as broad. Surface of the shell beset with hairs of moderate length, and,
more especially toward the extremities, with extremely long and coarse hairs, some of
them reaching one-third the length of the valves. Colour pale brown, semitransparent.
Length 1:1 mm.

Hab. St. Thomas, West Indies. Four specimens.

Among known species, Bairdia hirsuta Brady is the one which bears most resemblance
to the present, but the likeness is not remarkably close, except as to the setose clothing
of the shell. B. hirsuta was taken by the ‘Challenger’ Expedition in 33-38" South
latitude in the Pacific at depths of from 1375-1825 fathoms. Both B. hirsuta and
B. villosa are without marginal serrations or spines.

198 DR. G. 8. BRADY ON NEW OR

Family CYTHERID.E.

Genus Cytnere Miiller.

CYTHERE SICULA, sp. nov. (Plate XXV. figs. 1-7.)

Shell of the male (fig. 1), seen from the side, elongated, subquadrangular, widest in front
of the middle, more than twice as long as broad; anterior extremity broadly rounded,
posterior obliquely subtruncate, rounded off at the angles; dorsal margin sloping
steeply toward the front from the region of the hinge-tubercles, less steeply and with a
gentle curve backward; ventral margin straight, with a slight sinuation anteriorly:
seen from above (fig. 2) elongate-ovate, fully twice as long as broad, tapering evenly
to the obtusely pointed extremities, greatest width in the middle. Right valve larger
than the left, which it overlaps considerably on the dorsal and posterior margins; valve
of the left side much narrower, with no elevation over the hinge-tubercle and distinctly
excavated above the middle of its posterior margin. Valves fringed, except on the dorsal
and middle of the ventral margins, with closely-set, short hairs; the marginal portions
of the valves, more especially at the two extremities, form a smooth encircling flange
which is marked radially by transverse lines prolonged from the bases of the fringing
hairs ; bordering the inner margin of the flange, the shell-surface is marked out into
polygonal areas (fig. 4), the interspaces being dotted with small closely-set impressions ;
beneath the dorsal margin at its anterior third is, on each valve, a very conspicuous
polished tubercle, partially surrounded by a smooth, non-punctate area. ‘The shell of
the female is nearly as long as that of the male, but wider, and the lower half of the
posterior margin is prolonged into a wide angular beak (fig. 3). Length:88 mm. The
internal anatomy presents no characteristic features. ‘The antennules, antenne, and
third pair of feet are here figured (figs. 5-7).

fab. \n fresh water, Syracuse. Numerous specimens of both sexes.

This species has many points of resemblance to Cythere lutea Miiller and C. rubida
Brady; but from the former it is separated by the more angular outline and the con-
spicuous marginal flange, from the latter by slight diversity of form as weil as by its
greater size and more delicate sculpture; both of these are, however, littoral marine
forms, whereas the recorded habitat of C. sicula is “fresh water.” One can easily
imagine that differences such as characterise C. stcula may well have been produced by
change of environment in species like C. rudida or C. lutea.

IMPERFECTLY-KNOWN OSTRACODA.

199

To Dr. George Murray, F.R.S., of the Natural History Museum, South Kensington,
I am indebted for the opportunity of examining a series of Ostracoda from plankton
collections made by him in the North Atlantic.
form the species found in each gathering, their comparative abundance or scarcity

The following list shows in tabular

being noted roughly by the number of asterisks attached to each: * means scarcity ;

** moderate number; *** abundance.

Locality.

Lat, 52° 4°5 N.
| Long. 12° 27’ W.

Jat) 522 1S iicNe
Long. 15° 539 W.

Lat. 52° 20’ N.
Long. 15° 7-9 W.

Lat. 52° 27'°6 N.
Long. 15° 40' W.

a

Depth

in

fathoms.

270
374
464
620
650

Surface.

1710

150
310+
379
510
560

790

920
1065
1170
1275
1370
1470
1570
1670
1770

dg
a
I
Se
g 2 |2
S se || 2 a
Sales is | es
B o S = 8 o
REISTS 1 S18 18
SP] ei sis S
= = > Ss Ss
> | & & [Rx a, | @
38
Ss
8 * 5
Ld - = a a
8
&
3M] oo
2
*
?
RK
RE
Yat bette RK
tk RRR ae
v
HK
** eye oo |\*R
HHH) 5
KK
RE KK
Beailboo
LR
eK
Peel treme ema cere se sks
50 S33) wo. |) 62
no oe. || oo. KOEES
Ba
mai 56 | salt oo || oe
** ee
cell aes x
*?
\

5 NO a
rae
Bi
2/5
Oo 8
Sy, 45
Ps
Sails
8
3
8
Ps
Se
ie
o
S
s
lo
*
¥
#*
eK
2

inermis Claus.

Kx

a

3

5

5

2 ee

ag

a | >

o|%

A to

= | 3

s | 8

Se

g

S

= Ss

2 8

~

SS

B

* *
#X

‘ Many immature forms ; species not recognizable.

Conchecissa imbricata Brady.

|

* 7
x * KK %

**

cucullata, sp. n.

| Microconchecia clausii G, O. Sars.
Asterope sp.

|

*%

KE

WK

i ae ll die ‘ .
» io : ) ya ce
a ee

Ee a Pe

iy

PEATE) xox

202 NEW OR IMPERFECTLY-KNOWN OSTRACODA.

PLATE XXI.

Philomedes debilis, 3 (p. 186).

. Outline of shell seen from right side, x 53.

rf 5 above, X 55.

. Margin of shell round antennal sinus, x 110.
.. Antenna seen from side, x 84.

. One of the caudal lamine, X 120.

Cow

o

Asterope oculata (p. 179).

. Shell of male seen from left side, x 40.

As a above, x 40.

. Outline of shell of female seen from left side, x 40.
. Antennule of female, x 100.

. Internal branch of antenna of male, x 84.

. Mandibular foot, x 100.

. One of the caudal lamine of male, x 84.

5 35 ungues of female, x 240.

Fig.

SLD

He ee
ce) Ly) Woy (o')

o2

Pyrocypris americana, 9 (p. 185).

Fig. 14, Outline of shell, seen from left side, x 28.
15. Base of one of the principal antennular set, x 240.
16. Internal (rudimentary) branch of antenna, x 100.
17. Mandibular foot, x 84.
18. Apex of vermiform limb, with setz, x 240.
19. Caudal lamina, x 100.

Cyclasterope fascigera (p. 181).

Fig. 20. Shell of male, seen from right side, x 10.

<5 a above, x 10.

. Outline of shell of female, seen from left side, x 8.
AN ge 5 Pn above, x 8.

. Terminal joints and sete of antennule of male, x 24.
25. Joints of antenna of male, x 40.

26. Internal branch of antenna of male, x 40.

27. Mandibular foot of male, x 26.

28. Masticating process of mandible of female, x 120.
29. Caudal laminz of male, x 26.

30. Marginal armature of unguis of male, x 240.

él. 3 ay op female, x 240.

Bees

Cypridina granulosa, ? (p. 184).
Fig. 32. Outline of shell of female, seen from left side, x 20.
33. = a 5 above, X 20.
34. Internal branch of antenna, x 150.

FronisZLook Po Vel Wt PEIG.

G.S Brady, del®

Bale& Danielsson, Lt4, lith .
NEW OR IMPERFECTLY- KNOWN OSWRNCODVA § ,

Rig
ig.

Fig.

Fig. 2

IL
»)
2
oO.

1.,
5.

12.
13.

25.
26.

NEW OR IMPERFECTLY-KNOWN OSTRACODA.

PLATE XXII.

Codonocera cruenta, 3 (p. 188).

Shell seen from left side, x 25.

¢ r 95
9 6 above, X 25.

Antenna with internal (prehensile) branch and first swimming-seta

(the other setee omitted), x 84.

3a. Armature of claw, x 240.

Mandibular foot, x 60.
Maxilla of second pair, x 115.

}. End of vermiform limb, with sete, x 240.
7. Postabdominal laminz, x 60.

. Suctorial seta of antennule, x 200.

. Suctorial dises of the same, x 440.

. Copulatory organs.

(v.d., vasa deferentia.)

Cypridina insolita, 2 (p. 184).

. Shell seen from right side, x 16.

Inner branch of antenna, x 1.5.
First swimming-seta of antenna, x 115.

. End of vermiform limb, x 84.

Cypridina foveolaia, 2 (p. 184).

5. Shell seen from right side, x 16.

Be os above, x 16.

. Process of mandibular foot, x 120.
. End of vermiform limb, x 84.
. Postabdominal lamine, x 40.

Cypridinodes favus, 3 (p. 187).

. Shell seen from left side, x 16.

> 39 above, x 16.

. Last two joints and sete of antennule, x 300.
. One of the swimming-setee of antenna, x 240.
. Inner branch of antenna, x 115.

Mandibular foot, x 55.
Manxilla of first pair, x 55.

26 a, b. Sete of the same, x 300.

27.

Maxilla ot second pair, x 84.

27 a, b, c. Setze of the same, x 300.

28.

29.
30.
ol.

Manilla of third pair, x 84.
End of vermiform limb, x 120.
Postabdominal laminae, x 55.
liye, x 84.

ee Ve UGE a.

Lo

Geez, 24.

Bale & Danielsson, L*?, lith

G.S.Brady , del*

¥Y-KNOWN OSTRACODA

206 NEW OR IMPERFECTLY-KNOWN OSTRACODA.

PLATE XXIII.

Cypridopsis marmorata (p. 193).

Fig. 1. Shell, seen from right side, x 84.
2 above, x 84.

a” ”

Cypris letevirens (p. 193).
Fig. 3. Shell, seen from left side, x 25.
4; 4, s above, x 25.
5. Postabdominal ramus, x 84.

Cyprinotus dentato-marginatus (p. 196).
Fig. 6. Shell, seen from left side, x 40.

fod

7. Anterior margin of the right valve, x 84.

Cypris virens (p. 192).
Fig. 8. Shell, seen from left side, x 16.

Cyprinotus fragilis (p. 196).
Fig. 9. End of second foot, x 240.
10. Postabdominal ramus, x 90.

Cypris flexilis (p. 192).
Fig. 11. Outline of shell, seen from right side, x 16.
12. Antenna, x 40.
13. Maxilliped, x 40.
14. Foot of first pair, x 40.
15. Postabdominal ramus, x 40.

Sarsiella ornithoides (p. 189).
Fig. 16. Shell, seen from left side, x 55.
ie iss es above, x 55.
18. Antennule (imperfect), x 60.
19. Inner braneh of antenna, x 320.
20- Portion of one of the antennal sete, x 320.
21. Postabdominal lamina, x 240.

Asterope lichenoides, § (p. 180).
Fig. 22. Shell, seen from left side, x 16.
23. > rr above, x 16.
24. Inner branch of antenna, x 50.

Cyclasterope similis, 2 (p. 183).
. Outline of shell, seen from right side, x 12.
. Last two joints of antennule, x 55.
. Joints and first seta of antenna, x 55.
. Inver branch of antenna, x 84.
. Maxilla of first pair, x 40.

Fe
a9
wwnnvnww
C CONE D or

Seis Le ee Dol, KG JOM.

Bale & Danielsson, Lt4 lith .

G.S Brady, del?

NEW OR IMPERFECTLY-KNOWN OSTRACODA

INS SOI

208 NEW OR IMPERFECTLY-KNOWN OSTRACODA.

PLATE XXIV.

Conchecissa cucullata (p. 191).

ig. 1. Shell (with open valves) seen from outside, x 40.
2. Shell seen from left side, x 40.
3. Antennule (with frontal tentacle) of female, x 84.
4. Inner branch of antenna of male, x 84.
5. female, x 84.

6. Chewing-plates of mandible, x 240.

7. Postabdominal lamina, x 84.

8. Gullet and stomach, x 84.

9 3)

Euconchecia chierchie (p. 190).

Fig. 9. Outline of shell, ¢, seen from left side, x 55.
10. Antennule of male, x 120.
Tile 5 female, x 120.
12. Antenna of female, x 110.
13. Inner branch of antenna of male, x 110.
14. Mandible and palp of female, x 120.
15. Copulatory organ and caudal laminz of male, x 110.

Cyclasterope brevis, 2 (p. 188).

Vig. 16. Outline of shell seen from right side, x 16.
17. Last three joints of antennule (setze omitted), x 55.
18. Joints and first seta of antenna, x 84.
19. Portion of one of the antennal sete, x 240.
29. Inner branch of antenna, x 84.
21. Maxilla of first pair, x 40.
22. Postabdominal lamine, x 4.0.

Philomedes sordida, 3 (p. 186).

Fig. 28. Outline of shell seen from left side, x 40.
24. Inner branch of antenna, x 100.
25. End of vermiform limb, with sete, x 240.
26. One of the caudal lamin, x 100.

Doms Dol Goo Vol KM GIOKKI:

Bale & Danielsson, Lt jith .

G.S Brady, del?

NEW OR IMPERFECTLY- KNOWN OSWRAC ODES:

it

ae Mee

ae Hi

=]
ie:

ahien
spikes

4

210

Fig.

Fig.

NEW OR IMPERFECTLY-KNOWN OSTRACODA.

PLATE XXYV.

Oythere sicula (p. 198).

. Shell of male, seen from left side, x 45,

a . above, x 45.

. Shell of female, seen from left side, x 45.
. Portion of anterior margin of shell, x 240.
. Antennule of male, x 120.

. Antenna of male, x 120.

. Foot of third pair, x 100.

Bairdia longisetosa (p. 197).

. Shell, seen from right side, x 35.

- 5 above, x 39.

Cypretta sarsi (p. 195).

. Shell, seen from left side, x 50.

BS on above, x 50.

2. Portion of anterior margin of shell, x 84.

. Ventral margin of right valve, seen from inside, x 84.
. Terminal joint of last foot, x 440.

. Postabdominal ramus, x 240,

Candonella virescens (p. 193).

. Shell, seen from right side, x 46.

+5 5 above, x 46.

. Ventral margin of left valve, seen from inside, x $4.
. Portion of shell, x 240.
. Antenna, x 120.

21. Maxilla, x 240.

. Maxilliped of female, x 240.

$ male, left side, x 240.
” » Tight side, x 240.

25. Foot of first pair, x 120.

>, last pair, x 240.

27, Caudal rami, x 240.

. Copulatory organ of male, x 240.
. Spermatheca and caudal rami of female, x 240.

Candonopsis complanata (p. 196).

30. Outline of shell, seen from left side, x 25.

xp i above, x 25.

. Spine of second digit of maxilla, x 120.

. Maxilliped of female with basal portion of palp, x 120.
. Leg of second pair, x 84.

. Caudal ramus, x 84.

. Spermatheca of female, with spermatic coil, x 120.

Cyprinotus fragilis, 2 (p. 196).

. Outline of shell, seen from left side, x 25.

a es above, x 25.

. Spermatheca with spermatic coil, x 120.

Trans, Look Foo. Volt MM GCKIV.

SS

OS Se

Bae

oe

VET
ees a.

2
ve
?
Ze

(ee)
~J
_SSMsiin~ ASA

(

G.S.Brady, del¥ ; Bale & Danielsson, Lt; lith .
NEW OR IMPERFECTLY-KNOWN OSTRACODA

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CONTENTS.

V. On new or imperfectly-known Ostracoda, chiefly from a Collection in the Zoological
Museum, Copenhagen. By Goren Stewarvson Brapy, WD., LL.D., D.Sc.,
FERS. CMZ.S (Plates XX1-=X XV.) epee oe Dae ee

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VI. On the Myology of the Tongue of Parrots, with a Classification of the Order, based
upon the Structure af the Tongue. By Gro. P. Muper, A.R.CLS. Lond., P.Z.S.,
Lecturer on Biology, London School of Medicine for Women; and Demonstrator
of Biology, London Hospital Medical School.

Received March 4, read April 2, 1901.
[Prates XXVI.-XXIX. & Text-figures 1-16.]

THis investigation owed its origin to a suggestion of Prof. Howes, and was commenced
in 1896, during my tenure of the Marshall Scholarship, in the Huxley Laboratory,
Royal College of Science, London. A preliminary paper was communicated to this
Society in 1897, but its subject matter was not published, as it was deemed advisable
to incorporate it in the finished work.

I have to express my thanks to the Prosector of the Society, to Professors Stewart,
Howes, and D’Arcy Thomson, and to Mr. W. P. Pycraft, for the loan of the greater
portion of my material. To my past teacher, Professor Howes, and to Dr. P. Chalmers
Mitchell I have further to express my thanks for valuable advice given in the pre-
paration of the manuscript for the press.

The scientific names of the Parrots, the tongues of which I have described, are those
adopted by Salvadori. With but a few exceptions, the birds have been very carefully
compared with his descriptions, as made in his Catalogue of Parrots, and in those cases
(when tongues only were supplied to me) where identification was not possible, I have
carefully worked out the synonymy.

With regard to technical terms, I follow the osteological terms of Mivart (6 & 7)
and the myological of Gadow (4) and of Nitzsch (2).

The classification of the Order, appended to this memoir, is designed merely as an
index showing the general trend of the ascertained facts relating to the tongue.

Part I.— HISTORICAL.

Although the Parrots have occupied the attention of naturalists to a considerable
extent, their tongues, so far as internal structure is concerned, have received but little
notice.

It is now nearly forty years since Giebel described the hyoid bones of several species
of Parrots, and more than thirty since Nitzsch’s paper was published in which the
lingual myology of Ara macao (Psittacus macao Nitzsch) and Chrysotis leucocephala

VOL. XVI.—PART VY. No, 1.— October, 1902. 21

ie, MR. G. P. MUDGE ON THE MYOLOGY

(Psittacus leucocephala Nitzsch) was described, and I have been unable to find any
record either before or since this paper which deals with the subject.

The reason of this neglect is not far to seek, for I suppose that the tongue is about
the last structure in which the zoologist would seek for characters indicative of affinity.
But yet its characters, as affording a basis for classification, have not been altogether
neglected, for Baird, in his ‘Review of North-American Birds,’ has founded a genus,
Perissoglossa, upon them, and Gadow, in his paper “On the Structure of certain Birds
from Hawaii,” has laid stress on the shape and structure of the tongue. How little
such characters are to be relied upon at present is indicated by the diverse results
they have obtained, for the one would ally the Ceerebide to the Sylvicolide, and the
other to the Drepanidide.

Further, Lucas, in the ‘ Auk’ for 1894, has shown that the characters of the tongue
of birds have neither morphological nor physiological significance, ‘‘ for while the
skulls of two genera are widely separated their tongues are structurally alike,” and
“while certain birds (Certhiola) may possess a tongue adapted for honey-sucking, they
may yet possess a distinct liking for insects.” He has also shown that the ** Sandwich
Islands Drepanidide have a perfect tubular tongue, and some of the Meliphagide have
a suctorial apparatus and could thus feed on honey and nectar if they chose. Some
of them, as their stomachs testify, feed on fruit, some on spiders and insects.”

In the midst of such negative results came Mivart’s paper (6) on the “ Hyoid Bone
of Parrots,” in which he demonstrated that this structure did possess characters of
classificatocry value and by means of which the Loriide were marked off as a group
distinct from the Psittacidz. Working at the myology, I have not only corroborated
Mivart’s conclusion, but also that of Beddard and Parsons which was based upon a
study of the patagial tendons and the bronchial] rings, and have further arrived at
results which, as I trust to show in the course of this paper, justify us in using the
characters of the tongue for purposes of classification.

With respect to the literature, the earliest paper on the subject is by von Giebel (1),
who in 1858 described and figured the hyoid bones of several species of Parrots which
were then included under the genus Psittacus. In 1862 Nitzsch published a paper
entitled ‘Zur Anatomie der Papageien” (2), in which the myology of the tongue of
* Psittacus”” } was described for the first time.

The next paper appeared after a considerable interval, and it was only in 1886 that
Shufeldt, dealing with the osteology of Conwrus carolinensis (3), called attention to
the peculiar structure of the hyoid bone, and pointed out that “the thyro-hyal
elements show but little curvature along their continuities, and still less disposition to
curl up behind the cranium.”

In 1891, Gadow (4) described the myology, neurology, and osteology of the Parrot’s

* The two species of Psittacus described by Nitzsch are species of Chrysotis and Ara.

OF THE TONGUE OF PARROTS. 213

tongue: Psittacus leucocephalus, Microglossus aterrimus, and Ara macao were alone
dealt with, and the account being comparative and incorporated with the description of
the lingual myology of other birds, does not attempt to deal with the subject in an
exhaustive or detailed manner.

In 1893, he (4') divided the Parrots into two families, 7.e., Trichoglosside and
Psittacide, basing his classification upon the external characters of the tongue, viz., the
presence or absence of horny fibres (/ornfasern), the completeness or incompleteness
of the orbital ring, and the direction of the file-like markings on the upper beak.

In 1895 and 1896 St. G. Mivart (6 & 7) published some very complete descrip-
tions of the hyoid bones of various Parrots, and among others described and figured
for the first time those of Lorius domicella, Lorius flavo-palliatus, and Kos reticulata.
In this paper attention is directed to certain bony processes of which no previous
records exist, and the relationships of these to certain muscles of the tongue |
describe in the body of this paper.

Mivart further showed that the Order Psittaci is distinguished from every other
order of birds by the shape of its hyoid, and that the characters which determine this
are as follows :—

1. The posterior enlargement of the basihyal.
2. The growth upwards and forwards of a process on either side of the basihyal,
which he proposed to call the parahyal process.
. The presence of an os entoglossum (ceratohyal of Shufeldt) in the form either

(se)

of a single broad bone with a considerable central foramen, or, much more
commonly, of two lateral parts (entoglossals), which are united in their
anterior middle region by cartilage so as to leave a space between this and
their attachment to the basihyal.

He concluded that, among the Psittaci, the Loriide present a very distinctive
character, in respect of the growth forward of the parahyal processes anil their union
in the middle line to form the parahyal arch ; and in the course of this paper Lam able
to substantiate his conclusion, by the discovery that, in respect to their lingual muscles,
the Loriide also present distinctive characters, in reference to which they appear to
occupy an isolated position.

In 1893 Beddard and Parsons (5) called attention to certain points of similarity
in the myology of Parrots, and directed attention to the existence of differences in the
arrangements of the tendons of the tensor patagit muscle. ‘Their observations led
them to the conclusion that “ the patagial tendons of Ps?ttacus closely resemble those
ot Chrysotis” ; and this is corroborated by certain facts embodied in the present paper,
which show that a similar agreement exists between the two birds, in respect of a lingual
muscle which, within the range of Parrots so far studied, exhibits certain modifications.

The outcome of the present investigation shows that the lingual muscles of Parrots
are in the course of evolutionary changes, some of the muscles exhibiting the structural

212

214 MR. G. P. MUDGE ON THE MYOLOGY

variations indicative of these more markedly than others, and that the Loriide have
advanced farthest along the road of specialization. ‘These structural modifications
are such that a series of graded stages, starting from the most primitive form and

ending with the most specialized, can be determined,

Part II.— DESCRIPTION AND COMPARISON OF THE MUSCLES.

CeratoGLossus MuscLE.

(a) Inferior Ceratoglossus (basto-glossus of Nitzsch).—This muscle exhibits a series
of graded variations, and in one or two instances the variations are manifested among
the species of the same genus and even upon either side of the same tongue. A
comparison of its chief structural features shows that nine stages in the evolution of
the muscle may be made out (é#fra, pp. 266 & 268), and that there are two types of
structure, which I propose to call the “ wnipars” and ‘‘duopars” type. The unipars
type is typically represented in the first stage, the duopars type in the highest stages,
and the gradations from the one to the other in the intermediate stages.

Stage 1.

The most primitive form of the muscle is exhibited in Cacatua alba. It is inserted
tendinous into the anterior lateral process of the os entoglossum, and arises fleshy from
the posterior border of the basihyal and the margin of the whole length of the urohyal.
Its general relations may be understood by reference to Pl. XXVIII. fig. 25, which
represents its condition in Cacatua galerita. In particular, the extension of the
muscular origin along the urohyal (UR.) appears to be a most primitive character, and
in C. alba, C. sulphurea, and C. triton this is more strongly developed than in any
other Parrot, extending as it does to the extremity of the bony portion. In C. alba
the belly of this particular inner portion (cg.i.a!.) of the muscle is more strongly
developed than in any other species of Cacatua, the muscle of either side meeting each
other, but not uniting, in the middle line considerably forwards, and remaining in
contact throughout the remainder of their course backward to the extremity of their
origin. The inner portion of the muscle is not in any way separated from the outer
portion (cg.7.a.) as is partially the case in C. galerita, though there is a shallow groove
indicative of the first stage towards the attainment of this condition. I propose to
distinguish the whole of this muscle, which is almost exclusively related to the
basihyal and entoglossum, and only extends backwards upon the hypobranchial as far
as its head, as the ceratoglossus inferior anticus (¢q.2.a.).

There is given off from the ventral surface of the outer portion of the muscle a
muscular slip (cg.i!.), which passes backward and becomes attached to a transverse
tendon (w.fen.) that passes from the urohyal to the head of the hypobranchial.

OF THE TONGUE OF PARROTS. 215

I propose to call this muscle, which is very generally present, the ceratoglossus inferior
anticus accessorius (cg.i+.), and the tendon from which it arises as the wro-hypobranchial
tendon.

The muscle, as a whole, does not possess a distinct tendon, but the fascia of its
ventral surface is somewhat tendinous and anteriorly it is confluent with the similarly
tendinous fascia of the lateral ceratoglossus (cg.l.). The absence of a distinct tendon.
is very characteristic of the more primitive forms of the muscle, and from the condition
of the tendinous fascia here presented up to that of a strongly developed tendon in the
more specialized forms there is every conceivable gradation. In Cacatwaroseicapilla the
muscle is like that just described, but the groove between the inner and outer portions
of the muscle is here represented by a considerable thinning, so that these two portions
are partially separated one from the other, and the thinned portion of muscle has
developed a thin, flat, conical tendon whose apex is attached to the root of the urohyal ;
and the inner portion of the muscle (c¢g.7.a!.) arises, not from the urohyal, but from
the oval cartilaginous nodule (N.) which articulates with its ventral surface. In
Calyptorhynchus banksti and Calyptorhynchus funereus the muscle resembles that in
Cacatua roseicapilla, but differs from it in that the inner portion is inserted directly to
the urohyal, asin C. alba. In Ara ararauna the muscle is fundamentally like that
of Cacatua alba, but the inner portion (Pl. XXVIII. fig. 24, cg.z.a1.) is less strongly
developed, inasmuch as it does not extend on to the urohyal nor meet its fellow of
the other side in the middle line. A ceratoglossus inferior anticus accessorius is
absent.

Stage 2.

The muscle of the five species Just described is typically that kind which I propose
to name the wnipars type; 7. é.,it consists only of an anterior portion, which practically
does not extend beyond the posterior border of the basihyal.

In Cacatua galerita the muscle is like that in Cacatua alba, but differs from it in
‘that the inner portion (Pl. XXVIII. fig. 25, ¢g.7.a!.) is partially separated from the
outer (cg.t.@.) by a narrow area extended along the long axis of the muscle, in which
the muscular tissue is thinned, but not to quite the same extent that it is in Cacatua
roseicapilla ; it further differs in the splitting of the ventral tendinous fascia into an
inner and outer portion, which, however, still remain confluent in their anterior half,
and in the extension backwards along the inner surface of the hypobranchial, for about
the anterior fourth of the length of that, of a muscular tract (cq.i.p!.) derived from, and
continuous with, the outer portion (cg.i.a.) of the muscle. This small muscular tract
shows no signs of dividing off from the parent muscle, and it is the first definite
indication of the formation of a posterior portion of the muscle that reaches its
maximum development in the Loriide. <A glance at Pl. XXVIII. fig. 25 will show
that the tendinous fascia is elongated backwards in such a way that it appears to

216 MR. G. P. MUDGE ON THE MYOLOGY

suggest an early stage in the formation of a tendon for this small muscular tract
(cg.i.p'.). In virtue of this posterior extension of the outer portion of the muscle it
constitutes the second stage in its evolution, and inasmuch as the extended portion is

continuous with the parent muscle it is still of the unipars type.

Stage 3.

In Stringops habroptilus a further advance is represented in the slightly greater
extension of the muscular tract (Pl. XXVIII. fig. 26, ¢g.7.p.) along the hypobranchial,
and more particularly in that this extended part has become severed from the muscular
portion of the parent muscle (text-fig. 1, ¢g.7.a.), but is connected with that by

Text-fig. 1.

Stringops habroptilus.—Dorsal view of ccratoglossus inferior (right side). (Twice nat. size.)

cg.i.d. = ceratoglossus inferior anticus.
cg... = ss es (inner portion of),
cg... = on lateralis.

cg.i.a°. = the portion of ceratoglossus inferior anticus which arises from the urohyal.
cy.i.p. = ceratoglossus inferior posticus.

t'. = tendinous ventral fascia of cg.7.a.

t. = posterior prolongation of ¢’.

a. = point of insertion of muscle to anterior lateral process of entoglossum.

attachment to a slender prolongation (¢.) of its ventral fascia (¢!.). Thus, that which
is but a posteriorly directed extension (cg.t.p1.) of the outer portion of the parent
muscle in Cacatua galerita, is here an independent muscle (cg.i.p.) with an origin from
the fascia of the parent one and an insertion along the anterior third of the hypo-
branchial. I propose to speak of this muscle (cy.i p.), which reaches a much greater
development in more specialized forms, as the ceratoglossus inferior posticus. The
slender prolongation of the tendinous fascia to which it is attached, and which is

OF THE TONGUE OF PARROTS. 217

foreshadowed in Cacatua galerita, becomes in the higher stages evolved into a very
pronounced tendon, ‘The inner portion (cqg.i.a1.) of the ceratoglossus inferior anticus is
strongly developed, but not quite so pronounced as that in Cacatua or Calyptorhynchus,
nor does it, as in them, extend back to the extremity of the urohyal, but only along
its anterior half; it is of uniform thickness, not exhibiting any area of retrogression,
and its dorsal fascia also is slightly tendinous in its posterior region.

The muscle in Cacatua leadbeateri (text-fig. 2) is fundamentally like that in Stringops,
but differs from it in the following details:—The ceratoglossus inferior posticus
extends back along the hypobranchial through the anterior two-thirds, instead of only
a third; the inner portion of the ceratoglossus inferior anticus (text-fig. 2, cg.2.a!.) is
thin in a region (7.) in such a way that a more posterior portion (cg.7.a°.) related

Text-fig. 2.

cg.i ‘p-

Cacatua leadbeateri.—Ceratoglossus inferior, left side, dissected away from the hyoid bone and viewed from the
dorsal surface, after a small portion of the ceratoglossus inferior anticus had been dissected away in
order to reveal the tendinous fascia of the ventral surface. (Twice nat. size.) 1.=retrogressing tract. of
eg.t.a, Other lettering as in text-fig. 1.

to the urohyal tends to become separated from a more anterior portion (cq.7.a!.)
related to the basihyal, and in which the former is attached to the tendinous prolonga-
tion (¢.) that forms the origin of the ceratoglossus inferior posticus (cg.7.p.); the
tendinous prolongation just referred to is attached to the ceratoglossus inferior posticus
along the inner side of its dorsal surface, and not, as in Striéngops, along the middle line ;
that portion of the ceratoglossus inferior anticus which arises from the urohyal takes
its origin along the whole length of that, asin other species of Cacatua. A comparison
of the condition of this muscle in Cacatua leadbeateri with that on the left-hand side of
the tongue in Pétstes erythropterus (infra, p. 223, Pl. XXVIII. fig. 35) will show that

218 MR. G. P, MUDGE ON THE MYOLOGY

the exceptional condition of the latter is foreshadowed in that of the former, and that
it could haye arisen, and doubtless has arisen, by the completion of the incipient
retrogression which is indicated in the region (7., text-fig. 2), and by the development
of the tendinous prolongation (¢.) into a distinct tendon.

The muscle in Cacatua sulphurea is like that in Cacatua leadbeateri, but the cerato-
elossus inferior posticus only extends along one-third of the length of the hypobranchial,
in respect of which it resembles that in Stringops.

In Calopsittacus nove-hollandie (text-fig. 8) the muscle is like that in Stringops,
but the inner portion of the ceratoglossus inferior anticus is not so strongly developed.

In Nasiterna pusio the muscle is similar to that in Str/ngops, but the tendinous
portion of the ventral fascia (Pl. X- XIX. fig. 48) is restricted to a conical tract extending

Text-fig. 3.

Calopsitiacus novee-hollandie.—Dorsal view of ceratoglossus inferior (left side). A similar preparation to that
of fig. 1. (Twice nat. size.) Lettering as in text-fig. 1.

from the insertion at the anterior lateral process, over the ventral surface of the
anterior portion of the muscle, to its attachment to the ceratoglossus inferior posticus
(posterior portion of the muscle) (cg.i.p.). The attachment of the latter portion of the
muscle to this tendinous tract is somewhat more anteriorly situated than in Stringops
or any other Parrot. ‘The outer portion (cg.i.a.) of the ceratoglossus inferior anticus
is more strongly developed in its lateral extension than in most instances, while the
inner portion (¢g.2.a!.) does not extend back on to the urohyal.

The third stage is thus characterized by the fact that the posterior extension of the
ceratoglossus inferior anticus of Stage 2 has separated from the parent muscle, but
remains connected with that by attachment to a smali prolongation of its ventral
tendinous fascia, by the greater extension of the ceratoglossus inferior posticus along
the hypobranchial, and by a slight retrogression of the urohyal origin of c¢q.7.al.

Stage 4.
This stage is characterized by a slight retrogression of the inner border and posterior
extremity of the inner portion (cq.i.a1.) of the ceratoglossus inferior anticus, and by the
development in an antero-posterior direction, in the ventral tendinous fascia, of a very

OF THE TONGUE OF PARROTS. 219

slightly thickened tract that is prolonged backwards, and serves as an origin for the
ceratoglossus inferior posticus (Pl. XXVIII. figs. 27 & 28). This tract is part of the
substance of the ventral fascia of the muscle and cannot be separated from that without
injury ; it is not, therefore, an individual structure.

The ventral fascia of the muscle at this stage is still uniformly tendinous (Pl. XXVIII.
figs. 27 & 28), and in its general features resembles that of the earlier stages.

In Ara macao (Pl. XXVIII. fig. 27) the ceratoglossus inferior posticus (cg.i.p.)
extends along the hypobranchial (HB.) for the anterior third only, and the inner portion
(cq.7.a1.) of the ceratoglossus inferior anticus does not reach quite to the urohyal, but in
other respects is well developed. Unlike that in Ara ararauna, there is a cerato-
glossus inferior anticus accessorius (cg.7'.). Jficroglossus aterrimus is similar to Ara
macao, but the ceratoglossus inferior anticus accessorius is very small.

Cacatua triton, in respect of this muscle, is in its general features similar to other
species of Cacatua, but in addition it possesses the characters which belong to this
stage. It, however, deviates from this stage and belongs to that of the earliest in
the great development of the inner portion (cg.i.a'.) of the ceratoglossus inferior
anticus, which is even more strongly developed than in Cacatua alba; it shows no
signs of retrogression. ‘The ceratoglossus inferior posticus extends backwards along
the anterior third of the hypobranchial.

In Cyanolyseus patagonicus the muscle is like that in dra macao, but the cerato-
glossus inferior anticus accessorius (¢7.21.) has almost disappeared.

In Chrysotis ochrocephala (Pl. XXVIII. fig. 28) the muscle resembles that of dra
macao, but the ceratogiossus inferior posticus (cg.2.p.) extends farther along the hypo-
branchial, reaching to the end of the anterior two-thirds, and the inner portion (cq.7.a’ .)
of the ceratoglossus inferior anticus has undergone considerable retrogression in such a
way that the lateral half of its inner part has disappeared. I propose to indicate this
amount of retrogression by the numeral I]; when, as in other cases, the whole of the
inner portion has disappeared by the numeral III; when the extension on to the
urohyal has disappeared and the inner lateral retrogression is not greater than in II,
by I; and the fully developed muscle by O. ‘The ceratoglossis inferior anticus acces-
sorius (¢g.7'.) is very large, and arises from almost the whole length of the uro-hypo-
branchial tendon. In Chrysotis panamensis, C. westiva, and C. viridigena the muscle is
similar to that in @. ochrocephala, but the thickened tract in the tendinous fascia
is slightly more pronounced, and tends to approach the condition of that in the next
higher stage ; the ceratoglossus inferior anticus accessorius is like that in Ara macao.
In C. panamensis the ceratoglossus inferior posticus only extends one-half of the
length of the hypobranchial, and the inner portion of the ceratoglossus inferior anticus
is more strongly developed, not having retrogressed beyond stage I.

VOL. XVI.—PART V. No. 2.—October, 1902. 2K

220 MR. G. P. MUDGE ON THE MYOLOGY

Stage 5.

In this stage the ventral fascia of the muscle is still tendinous, and to the same
extent as that of the lower stages, but the thickened tract of Stage 4 has become
slightly more pronounced, and has partially separated from the tendinous fascia, so
that to a certain degree it is an individual tendon. There is also a very marked
tendency for the ceratoglossus inferior posticus to extend back to the posterior extremity
of the hypobranchial, and the retrogression of the inner portion of the ceratoglossus
inferior anticus is becoming very pronounced, the muscles of some Parrots haying
reached almost complete retrogression (=III) in respect of this portion.

In Psittacus erithacus the muscle is typically represented at this stage. It is figured
on Pl. XXVIII. fig. 29, and in its general features resembles that in Chrysotis
ochrocephalus, from which it differs, in addition to the characters of the tendon, in
that the ventral fascia is thicker (which cannot be well represented in a figure) and the
inner portion of the ceratoglossus inferior anticus (¢g.2.a!.) sends back a small twig on
to the head of the hypobranchial (HB.). The ceratoglossus inferior anticus accessorius
(cg.7.) is of the usual type, and is not like that in Chrysotis ochrocephalus.

The muscle in Coracopsis vasa (Pl. XXVIII. fig. 51) is similar to that in Psittacus,
but the inner portion (¢g.i.a’.) of the ceratoglossus inferior anticus is very strongly
developed, and anteriorly, like that in Ara macao, it is covered with a tendinous fascia ;
it does not, like that in Psittacus, send back a small twig on to the hypobranchial.
The ceratoglossus inferior posticus (¢g.i.p.) extends along the hypobranchial for its
anterior half only.

In Paleornis torquata (Pl. XXVIII. fig. 32) and Psephotus xanthorrhous the cerato-
glossus inferior posticus reaches to the posterior limit of the hypobranchial; in the
latter Parrot the inner portion of the ceratoglossus inferior anticus has quite disappeared
(=stage III); but in Palwornis it has only attained to between this and II.

In Conurus holochlorus, C. jendaya (Pl. XXVIII. fig. 56), and C. cactorum
(Pl. XXVIII. fig. 50) the ceratoglossus inferior posticus extends nearly the whole
length of the hypobranchial. In the last of these three Parrots the inner portion of
the ceratoglossus inferior anticus (cg.i.a’.) is strongly developed, that of either side,
turning inwards, becomes slightly separated from the outer part and meets its fellow
in the middle line; in the first-named Parrot it has retrogressed almost to stage II, and
in the second almost to stage ILI.

In Deroptyus accipitrinus the ceratoglossus inferior posticus extends a little more
than the anterior two-thirds along the hypobranchial, and the inner portion of the
ceratoglossus inferior anticus has retrogressed to stage II. ‘The ceratoglossus inferior
anticus accessorius resembles that in Cacatua galerita (Pl. XXVIII. fig. 25) in its
mode of attachment to the uro-hypobranchial tendon—~. ¢., it is attached to the ventral
surface, instead of to its anterior margin as in the majority of Parrots.

In Lclectus pectoralis (Pl. XXIX. fig. 49) the ceratoglossus inferior posticus (cg.7.p.)

OF THE TONGUE OF PARROTS.

Lo
bo
a

extends only one-half the length of the hypobranchial, and is continued forwards
beyond the posterior edge of the basihyal to a greater extent than usual, in respect of
which it resembles Nasitterna; the tendinous tract from which it arises is situated on
its outer side and not along its middle line. The inner portion of the ceratoglossus
inferior anticus (cg.i.a'.) has reached stage II in its retrogression, and its posterior
extremity is prolonged into a curved finger-like process; like that in Coracopsis and
Ara macao, its anterior portion is covered with a tendinous fascia.

In Brotogerys pyrrhopterus (Pl. XXVIII. fig. 33) the muscle is different on either side
of the tongue, that on the right having the general characters of this stage, in which
the ceratoglossus inferior posticus extends to the posterior extremity of the hypo-
branchial, while the inner portion of the ceratoglossus inferior anticus has reached
stage II of retrogression. On the left-hand side the ceratoglossus inferior posticus
shows evidence of a retrogressive atavism, and has gone back to the condition of that
in Cacatua galerita (Stage 2),in respect of the fact that it is represented by a posterior
extension (cg.i.p'.) of the ceratoglossus inferior anticus, which reaches back as far as the
anterior third of the hypobranchial. Behind it there is an elongated conical muscle
(cq.t°.), originating by its apex from the posterior end of the ventral surface of the
basihyal, and inserted by its base along the remaining two-thirds of the hypobranchial ;
it is not quite clear what this muscle represents, for, as far as its condition in Brotogerys
is concerned, it might equally well be interpreted either as a part of the ceratoglossus
inferior posticus or as a dorsal accessory ceratohyoideus. In Psittinus incertus (infra
p. 227, & Pl. XXVIII. fig. 34) there is a similar condition, but here the muscle can be
clearly seen to be a portion of the ceratoglossus inferior posticus, becoming separated
from the parent muscle.

Stage 6.

In this stage the ventral fascia of the ceratoglossus inferior anticus, though still
tendinous, is not so decidedly so as in the last stage, and the tendon derived from it is
now more distinctly developed. ‘The ceratoglossus inferior posticus in all cases, with
one exception and another partial one, extends back to the posterior extremity of the
hypobranchial, and, in respect of that, attains the highest condition of the muscle. In
all cases, also, with but two exceptions, the inner portion of the ceratoglossus inferior
anticus has attained either stage II or II] in its retrogression.

In Platycercus eximius (Pl. XXIX. fig. 44) the muscle reaches its highest development
for this stage, the specialized condition of that in Pezoporus excepted. The cerato-
glossus inferior posticus extends baekwards to the posterior limit of the hypobranchial
(=); the inner portion (cg.i.a'.) of the ceratoglossus inferior anticus has quite
disappeared (=III); the ventral fascia is only slightly tendinous, and the tendon
derived from it is well developed; and the ceratoglossus inferior anticus accessorius
(cqg.i'.) is relatively small. In Pwocephalus riippelli the muscle is similar to that of
Platycercus, but the ceratoglossus inferior posticus extends forwards a little beyond

2K2

222 MR. G. P. MUDGE ON THE MYOLOGY

the posterior margin of the basihyal, and the ceratoglossus inferior anticus is peculiar
in that its origin is from the head of the hypobranchial, as well as from the posterior
portion of the basihyal. In Pwocephalus robustus the muscle is almost identical with
that of P. riippelli, but the immer portion of the ceratoglossus inferior anticus has
only reached stage II of retrogression. In Bolborhynchus lineolatus (Pl. XXIX. fig. 45)
the muscle is similar to that in Matycercus, but the tendon of the ceratoglossus
inferior posticus is slightly more pronounced and to a small extent spreads out in a
fan-shaped form at its junction with the muscle; the inner portion of the ceratoglossus
inferior anticus is also not the same, since it has only reached between stages IL and III
in its retrogression, and the ceratoglossus inferior anticus accessorius (¢q.7'.) is well
developed. In Tanygnathus miillert the muscle is very similar to that in Bolborhynchus,
except that the tendon of the ceratoglossus inferior posticus is not quite so strongly
developed; the inner portion of the ceratoglossus inferior anticus has not reached
beyond stage II in retrogression, and upon the right side of the tongue it is prolonged
backwards in the form of a little strip on to the hypobranchial, as in Psitteeus
(Pl. XXVIII. fig. 29) and Ara macao. In Prioniturus sp.? the muscle is like that in
Bolborhynchus, but the inner portion of the ceratoglossus inferior anticus has not
reached beyond stage II in retrogression.

In Pezoporus formosus the muscle is very specialized, and were it not that the
ventral fascia is still tendinous (Pl. X XIX. fig. 47) in its anterior portion, and that it
possesses a remarkably weli-developed ceratoglossus inferior anticus accessorius (cg.2".), I
should have placed it in the highest stage with Hos. The inner portion of the cerato-
glossus inferior anticus has quite disappeared. The tendon of the cerotoglossus
inferior posticus is very strongly developed, as strongly as that in Kos, and the muscle
itself is very big and divided into three portions. This division of the muscle is unique,
and, if we except Psittinus and Brotogerys, in which the division is of another nature,
does not occur in any other Parrot. The three parts into which it is divided lie
one above the other ventro-dorsally ; I propose to distinguish each as follows:—
the ceratoglossus inferior posticus ventralis (Pl. XXIX. fig. 47, a), which arises from
the tendon at the level of the anterior head of the hypobranchial and is inserted by a
broad fleshy belly to the inner surface of the anterior two-thirds of the hypobranchial ;
the ceratoglossus inferior posticus medius (Pl. XXIX. fig. 47, & text-fig. 4, y), arises
from the extremity of the tendon and is inserted into the posterior third of the hypo-
branchial; and the ceratoglossus inferior posticus dorsalis (Pl. XXIX. fig. 47, &
text-fig. 4, 3), arises from the dorsal surface of the tendon from its posterior extremity
to the level of the anterior head of the hypobranchial, and is inserted along the greater
portion of the length of the hypobranchial. Of these, the ¢. 7. p. medius is the stoutest
and is oval in transverse section ; the ¢.7. p. dorsalis is the longest, and is also almost as
stout as the ‘“ medius”; while the c. @. p. ventralis is flat.

In Psittinius incertus (Pl. XXVIII. fig. 34) the muscle exhibits the characters of

OF THE TONGUE OF PARROTS. 223

this stage. The inner portion of the ceratoglossus inferior anticus has retrogressed to
stage I]. The ceratoglossus inferior posticus extends backwards nearly to the posterior
extremity of the hypobranchial, and forwards a little anterior to the hinder margin of
the basihyal; posteriorly it gives offa muscular strip (¢g.7?.) which passes inwards and
forwards to the posterior border of the basihyal and near to the root of the urohyal
(cf. Brotygerys, ante p. 221). This little strip is only found on the left-hand side of
the tongue ; it is developing a very small tendon at its posterior extremity.

In Ptistes erythropterus (Pl. XXVIII. fig. 55) the inner portion of the ceratoglossus
inferior anticus has retrogressed to stage I, and the ceratoglossus inferior posticus of
the right side is like that in Bolborhynchus. On the left side it is very different, and
the tendon gives origin to two divergently arranged muscles, the outer (cq.i.p.) of which
is inserted to the anterior half of the hypobranchial, and the inner (cq.7.a?.) to the

Text-fig. 4.

Pezoporus formosus.—Ventral view of a dissection of the left ceratoglossus inferior posticus to show the
division of the muscle. The ventral layer (ceratoglossus inferior posticus ventralis=a) has been removed.
(Thrice nat. size.)

H.B. = hypobranchial (left side).
t. = tendon of ceratoglossus inferior.
a. = anterior limit of the insertion of the ventral division of the muscle.
y. = median division of the muscle.
3. = dorsal division of the muscle.

urohyal. It thus exhibits the completed stage of that condition which was fore-
shadowed in Cacatua leadbeateri (cf. ante, p. 217), and which could be reassumed
if the inner portion of the ceratoglossus inferior anticus (cg.7.a'.) were to grow
backwards and become confluent with the urohyal portion (cq.t.a?.) of the posterior
ceratoglossus. A comparison of the two muscles leaves but little doubt that the
urohyal portion (cg.i.a.2) isa portion of the inner part of the ceratoglossus inferior
anticus which has separated from that and secondarily become agtached at an early
stage to the tendon of the ceratoglossus inferior posticus. The* early stage in this

224 MR. G. P. MUDGE ON THE MYOLOGY

separation, and the secondary attachment of the muscle to the tendon, is actually seen
in Cacatua leadbeateri. Why the assumption of this particular condition should be
confined to the left side, or why the asymmetrical departure should always occur on
the left side, is a question which the present range of facts cannot answer.

In Nestor notabilis (Pl. X XIX. fig. 46) the ceratoglossus inferior posticus (¢q.2.p.)
only extends back along the anterior two-thirds of the hypobranchial, and its tendon
is very strongly developed. A ceratoglossus inferior anticus accessorius is absent.

Stage 7.

In this stage the ventral fascia of the ceratoglossus inferior anticus is no longer
tendinous, as a consequence of which the tendons of the ceratoglossus inferior posticus
and ceratoglossus lateralis are independent, except at their common origin at the
anterior lateral process. ‘The tendon of the ceratoglossus inferior posticus is slightly
more strongly developed than in the earlier stage, and without a single exception the
muscle itself extends back to the posterior limit of the hypobranchial (=). The
inner portion of the ceratoglossus inferior anticus has completely disappeared (=II1)
in about one-half of the muscles examined.

In Pyrrhura leucotis (Pl. XXIX. fig. 40) the muscle exhibits the highest characters
of this stage, 7. €., the tendon is well developed and spreads out to a small degree in a
fan-shaped form at its attachment to the ceratoglossus inferior posticus; the latter
extends along the whole length of the hypobranchial, and the inner portion of the cerato-
glossus inferior anticus has disappeared. In Nymphicus uveensis and Cyanorhampus
auriceps the muscle is similar to that in Pyrrhura. In Loriculus galgulus (Pl. X XIX.
fig. 42) the inner portion of the ceratoglossus inferior anticus persists as a small
vestige (=between II & III) and smaller posteriorly than anteriorly. The tendon
spreads out in a fan-shaped form upon the ventral surface of the ceratoglossus inferior
posticus at its junction with that, and upon the dorsal surface it runs back as a narrow
tract, similar to that on the ventral surface of the muscle in Lorius flavo-palliatus
(Pl. XXITX. fig. 38). In Psittacula passerina the muscle (Pl. XXIX. fig. 41) is
similar to that in Pyrrhura, except that the inner portion of the ceratoglossus inferior
anticus is like that in Loriculus. The ceratoglossus inferior anticus accessorius (¢q.i!.)
is supplemented by a second one (cg.i?.), which arises not from the parent muscle itself,
but from its tendon. I propose to call it the ceratoglossus inferior anticus acces-
sorius secundus. In Caica leucogaster the muscle is similar to that in Pyrrhura, though
the tendon is somewhat thinner, and the inner portion of the ceratoglossus inferior
anticus persists, and for this stage is strongly developed (=TI).

In Pyrrhulopsis splendens the muscle exhibits several peculiarities: the inner
portion of the ceratoglossus inferior anticus is almost primitive on the left side, since
it reaches to the middle line as in Ara macao (Pl. XXVIII. fig. 27) (= 1), but on
the night side it has retrogressed to stage I1; and anteriorly, that of the latter side

OF THE TONGUE OF PARROTS.

i)
bo
C1

sends forwards a small muscular tract which becomes confluent with the outer border
of the right hypoglossus rectus, very similar to that in Stringops (Pl. XXVIII. fig. 26),
but differing from it in its partial separation from the parent muscle and in its greater
size. The fibres of the ceratoglossus inferior posticus are sagittally arranged, the
tendon extending backwards for some distance between the two rows of converging
fibres; the sagittal arrangement is very similar to that of the ceratoglossus inferior
posticus dorsalis of Pezoporus (Pl. XXIX. fig. 47, 6, & text-fig. 4, p. 223).
Were the inner row of fibres to lose its connection with the tendon and to become
attached by its anterior extremity to the posterior margin of the basihyal, the muscle
would repeat the condition exhibited by that of the left-hand side in Brotogerys and
Psittinus, assuming that, coincidently with the separation from the tendon, the fibres
slightly altered their direction.

In Pyrrhulopsis personata the muscle is similar to that in P. splendens, but the
ceratoglossus inferior anticus is the same on both sides, resembling the right-hand one
of the latter bird, but not possessing the anterior extension to the hypoglossus; and
the fibres of the posterior ceratoglossus are not so markedly sagittate in their
arrangement.

Stage 8.

As in the lower stage (7) the ventral fascia of the ceratoglossus inferior anticus is
not tendinous, but the tendon is much more strongly developed and extends farther
posteriorly along the ceratoglossus inferior posticus. The latter muscle is always
strongly developed and reaches to the posterior extremity of the hypobranchial. The
inner portion of the ceratoglossus inferior anticus in two of the three instances
examined has undergone complete retrogression (= III). A ceratoglossus inferior
anticus accessorius is absent.

In Lorius domicella (Pl. XXIX. fig. 37) the fascia of the ceratoglossus inferior
posticus (cg.i.p.) at the posterior extremity of the muscle is tendinous, and the muscle
itself is not attached, except by connective tissue, along the whole surface of the
hypobranchial ; the tendinous fascia is thus probably correlated with the loss of power
resulting through a reduction of attaching surface. Posteriorly the muscle is merged
with the posterior portion of the superior ceratoglossus. ‘The ceratoglossus inferior
anticus (cg.i.a.) is relatively small and tends to divide into a ventral inner and a dorsal
outer portion ; its inner portion has practically reached stage III in retrogression. In
Lorius flavo-palliatus (Pl. XXIX. fig. 58) the ceratoglossus inferior anticus does not
tend to split into two portions and its inner part has only reached stage II in retro-
gression. ‘The ceratoglossus inferior posticus is somewhat stouter than in L. domicella,
and the tendon runs back upon its mid-ventral surface for about half itslength. In Vine
australis the muscle is similar to that in Lorius domicella, except that the origin of the
ceratoglossus inferior posticus is like that in Z. flavo-palliatus, and the ceratoglossus
inferior anticus does not split into two portions.

26 Mk. G. P. MUDGE ON THE MYOLOGY

to

Stage iO),

This stage differs from the last only by the marked manner in which the posterior
end of the tendon spreads out in a fan-shaped form (Pl. XXIX. fig. 39) over the
anterior half of the ceratoglossus inferior posticus.

Eos riciniata is the only one of the Parrots examined that exhibits this particular
character developed to the same extent. The ceratoglossus inferior anticus is merged
with the lateral ceratoglossus along its whole length, except where the uro-hypobranchial
tendon passes between them to its attachment at the basihyal; its inner portion has
completely retrogressed (= ITI). The ceratoglossus inferior posticus is like that in
Lorius flavo-palliatus.

(b) Lateral Ceratoglossal.—This muscle arises fleshy from the dorso-lateral surface
of the hypobranchial and is inserted by a tendinous insertion, common to it and the
inferior ceratoglossal, to the anterior lateral process of the os entoglossum. In some
cases its origin posteriorly is from the dorsal surface of the hypobranchial, and it
gradually shifts, as it runs forwards, to the lateral surface. The chief differences
which it exhibits are concerned with the amount of its extension along the hypo-
branchial, in its confluence or separation from the ceratoglossus inferior anticus, and
in the nature of its tendon, 7.é@., as to whether it is a distinct tendon or merely a
tendinous fascia. With respect to the last character, the tendon varies in precisely
the same way and in correlation with that of the inferior ceratoglossal, being a distinct
tendon when that of the latter is so, and of the nature of a tendinous fascia otherwise ;
in the cases where it is of the latter description, the two muscles are covered by a
single fascia, and the tendon of the lateral ceratoglossal, like that of the inferior
ceratoglossal, is evolved as a thickened tract, the progress of its evolution keeping pace
with that of the latter muscle.

In Cacatua alba, C. leadbeateri, and Calyptorhynchus funereus the muscle extends
backwards along the anterior third of the hypobranchial; in the last-named Parrot it
is slightly more than this, In Ara, Cyanolyseus, Cacatua triton, C. sulphurea, C. rosei-
capilla, C. galerita (Pl. XXVIII. fig. 25), Calyptorhynchus banksi, Deroptyus, Micro-
glossus, Nasiterna, Nestor, Psittacus (Pl. XXVIII. fig. 29), Psittacula, Psephotus,
Peocephalus robustus, and Stringops (Pl. XXVIII. fig. 26) it extends along the
anterior half. In Coracopsis, Chrysotis panamensis (Pl. XX VII. fig. 14), C. estiva,
C. viridigena, Calopsittacus, Pawocephalus riippelii, Tanygnathus, Nymphicus, Conurus
cactorum. Lrotogerys, Palwornis (P\. XX VILL fig. 82), Pyrrhulopsis, and Loriculus
it extends along the anterior two-thirds. In Psittinus, Chrysotis ochrocephala
(Pl. XXVIII. fig. 28), and Pionopsittacus it is just slightly more. In Lorius
(Pl. XXIX. fig. 57), Hos (Pl. XXIX. fig. 59), Vint, Cyanorhamphus, Prioniturus,
Conurus holochlorus, C. jendaya, Pyrrhura, Caica, Pezoporus, Ptistes, Bolborhynchus,
Platycercus, and Eclectus it extends to or near the posterior extremity of the bone.
In Platycercus and Eclectus the muscle turns to the dorsal surface in its posterior

OF THE TONGUE OF PARROTS. 227

two-thirds. In Cacatua galerita, C. roseicapilla, Catyptorhynchus banksi, Conurus
Jjendaya, C. cactorum, C. holochlorus, Psephotus, Platycercus, Paocephalus robustus,
Bolborhynchus, Psittinus, Paleornis, Psittacula, Cyanorhamphus, Nymphicus, Ara
macao, Nestor, and Hos the muscle is confluent with the ceratoglossus inferior anticus.
In Cyanolyseus, Microglossus, Pyrrhura, Caica, Ptistes, Tanygnathus, Peocephalus
riippelli, Deroptyus, Psittacus, Coracopsis, Ara ararauna, and Cacatua sulphurea there
is an incipient division commencing, usually more marked at the posterior end.
In Calopsittacus, Chrysotis viridigena, C. ochrocephala, C. panamensis, Lorius flavo-
palliatus, Pionopsittacus, Cacatua alba, C. leadbeateri, C. triton, Prioniturus, Stringops,
Pyrrhulopsis, Loriculus, and Vini the division of the two muscles is more or less
distinctly indicated in the posterior half of their common course. In Lorius domicella,
Pezoporus, and Eclectus the two muscles are divided, more or less, along their whole
common course. In such forms as Cacatua and Stringops, where the fascia is
continuous and tendinous, the division is only apparent when the muscle is dissected
away and examined from the dorsal surface. Even then the division is not so
pronounced as in the other muscles with distinct tendons, and is hardly comparable
with them, since the fascia remains undivided.

(c) Superior Ceratoglossal.—This muscle is exhibited in its primitive form in
Cacatua, Ara ararauna, Calyptorhynchus, and Calopsittacus. In Cacatua galerita
(Pl. XXVII. fig. 13) the muscle arises from the dorso-inner surface of the anterior
half of each hypobranchial, and passing forwards and slightly inwards over the dorsal
surface of the basihyal, from which it also in part arises, becomes inserted into the
thick sheath investing a conical mass of dense connective tissue (mg!.) that lies in
the dorsal concavity of the entoglossum (EN.). In a large number of Parrots this
conical mass of tissue is either entirely replaced by muscle or by a mixture of muscle
and connective tissue ; and | propose to speak of it when muscular as the mesoglossus
muscle (ag.), and when otherwise as the mesoglossus tissue (mg!.). In Cacatua yalerita
the two halves of the superior ceratoglossus become confluent just before reaching
their insertion, and each narrows somewhat as it passes forwards from its origin.
In Cacatua leadbeateri, C. alba, and C. sulphurea the muscle is like that in C. galerita.
In C. triton the two halves each receive a small bundle of auxiliary fibres which arise
from the basihyal at the roots of the parahyal processes. In Calopsittacus nove-
hollandie the muscle differs from that in Cacatua galerita in that its origin extends
farther back upon the hypobranchial, and in Coracopsis vasa, Nymphicus wowensis, and
Psephotus xanthorrhous in that it does not extend beyond the anterior third. In
Calyptorhynchus funereus the muscle is like that in Cacatwa galerita, but in Calypto-
rhynchus banksi it arises from the anterior fifth only of the hypobranchial, and from
the insertion of the muscle (text-fig. 5, ten.) there runs backwards a bifid tendon, each
fork of which extends for a short way only along the inner side of each half of the
muscle; to the inner side of each of the latter there is a small muscular bundle (cy.s.a.)

VOL. XVI.—Pakr? Vv. No. 3.—October, 1902. Db

228 MR. G. P. MUDGE ON THE MYOLOGY

given off, each possessing an independent origin along the anterior half of the dorso-
lateral surface of the urohyal, and which I shall allude to as the ceratoglossus superior
accessorius. ‘The condition of the muscle which is exhibited in this Parrot is very
similar to that in Psittinus incertus (text-fig. 5, cg.s., ¢g.8.d., ten.). In Cacatua rosei-
capilla the muscle in respect of its origin and insertion is like that in Cacatua
galerita, but resembles Calyptorhynchus banksi in the possession of a ceratoglossus
superior accessorius, from which it differs, however, because the origin of this extends
the whole length of the urohyal and it is almost completely separated from the parent

Text-fig. 5,

Psittinus incertus.—Dorsal view, to show the connection of the ceratoglossus superior with the mesoglossus
and the formation of an accessory muscle (cy.s.a.), partially separated from the parent one by a bifid
tendon (ten.). (Thrice nat. size.)

Additional letters.

cg.s. = ceratoglossus superior. mg. = mesoglossus.
COC — 3 5 accessorius. P,P. = parahyal process.
H.B. = hypobranchial. ten. = tendon,

muscle. In Pyrrhura leucotis (Pl. X XVII. fig. 19) the muscle is similar to that in
Cacatua galerita.

In Stringops habroptilus (Pl. XXVII. fig. 18) the origin of the muscle extends back
to the anterior third only of the hypobranchial, and in the possession of a bifid tendon
running backwards from its insertion it is similar to that in Calyptorhynchus banksi,
though it is much more strongly developed. A ceratoglossus superior accessorius
(cq.s.a.) like that in Cacatua roseicapilla is present, but differs slightly from that in its
insertion to the crura of the bifid tendon, instead of to the muscle itself, so that it is
otherwise completely separated from the parent muscle.

OF THE TONGUE OF PARROTS. 229

In Ara ararauna (text-fig. 6) the muscle is like that in Cacatua galerita, but it
passes over the basihyal without forming an origin from it. In Ara macao the muscle
is similar to that in A. ararauna, but the two halves are distinct right up to their
insertion and a rudimentary bifid tendon is present (Pl. XXVII. fig. 20, cg.s.).
In Microglossus aterrimus it is like that in Ara ararauna, but there appears to be
an additional insertion to the dorsal concavity of the rounded anterior extremity of

Text-fig. 6.

Ara avarauna.—Dorsal view. The trachea, thyrohyoideus and thyroglossus have been removed, and upon
the right, also the stylohyoideus and sternohycideus and a part of the anterior portion of the meso-
glossus, in order to show the rounded cartilaginous extremity of the entoglossum, over which the sheath
of the muscle works. (Nat. size.)

Additional letters.

C.B. = cerato-branchiul. s.h. = stylohyoideus.

B.H. = basihyal. hg.o. = hypoglossus obliquus. st.h. = sternohyoideus.
U.R. = urostyle.

E.N. = entoglossum.

the basihyal, which lies immediately ventrad of the usual insertion (cf. Mivart,
P.Z.S. 1895 and 1896).

In Chrysotis ochrocephala (Pl. XXVII. fig. 12) and Deroptyus accipitrinus the
muscle is similar to that in Cacatua galerita, but its origin along the hypobranchial
is not quite so extensive, and anteriorly it receives on either side a small bundle of
fibres arising from the ventral surface of the hyoid, and which appears to be a portion
of the hypoglossus obliquus forming a new connection. In Chrysotis (viridigenalis)

2u2

220) MR. G. P. MUDGE ON THE MYOLOGY

viridigena there is a rudimentary bifid tendon a little smaller than that in Conurius
jendaya (PI. XXVI. fig. 9), but otherwise similar. In Chrysotis panamensis (PP). XX VII.
fiz. 14) there is an unpaired ceratoglossus superior accessorius (cy.8.@.) arising from
the left-hand parent muscle and attached to the root of the urohyal. In Chrysotis
wstiva the attachment of the muscle to the fascia of the mesoglossus is unique ; a small
triangular cartilage, having rounded ventral and dorsal surfaces, is fixed by its base to
the mesoglossus, while its other two sides form an insertion for the two halves of the
superior ceratoglossus, each to each. The position of this cartilage with respect to
the hyoid bone is immediately dorsad of the slight concavity in the rounded extremity
of the basihyal. Apparently this concavity is present in the hyoid bones of all
Parrots so far examined (cf. Mivart, P. Z. S. 1895 and 1896), but no meaning can be
attached to its presence. So far as this Parrot is concerned, this little cartilage
explains the concavity, for together they form a shallow ball-and-socket joint
arrangement. ‘The cartilage is present in no other Parrot, while the concavity is
almost generally so. ‘There is also present a bifid tendon, similar in its relation and
strength of development to that in Conwrus jendaya (P]. XXVI. fig. 9). In Nasiterna
pusio the muscle is like that in Chrysotis ochrocephala, but does not possess the lateral
bundle of fibres on either side.

In Pyrrhulopsis splendens and P. personata the muscle is like that in Chrysotis
ochrocephalus, but the muscle is splitting posteriorly into a larger dorsal and a smaller
ventral bundle; the former arises from the hypobranchial, and the latter from the
basihyal.

In Psittacus erithacus (Pl. XXVII. fig. 15) the muscle extends back along the
anterior half of the hypobranchial, but at that point where is its Insertion in other
Parrots it is continuous with the mesoglossus muscle, and is not inserted into the
fascia of that, as in other Parrots.

In Conurus jendaya (Pl. X XVI. fig. 9) the muscle arises, as in Stringops, from the.
anterior third only of the hypobranchial, and it possesses a bifid tendon of insertion, the
rami of which extend along the middle of each muscle, and not along the inner side
as in Stringops and Psittinus. ‘here is present on the right side only a ceratoglossus
superior accessorius (cg.s.a.)—a unilateral condition similar to that in Chrysotis
panamensis, but occurring on the opposite side of the tongue. In C. cactorwin it is
like that in C. jendaya, but there is no accessory muscle. In C. holochlorus as in
C. cactorwm, but the bifid tendon is more strongly developed than in any other species
of Conurus. In Cyanolyseus patagonicus and Loriculus galqulus as in C. cactorum, but
there is no bifid tendon. In Pinopsittacus pileatus as in Conurus cactorum.

In Eclectus pectoralis (text-fig. 7) the origin of the muscle is from the anterior
fifth only of the hypobranchial, and the bifid tendon of insertion is very broad, its
rami extending backwards over the dorsal surface, in the mid-line of each half of the
muscle.

OF THE TONGUE OF PARROTS. 231

In Paleornis torquata (Pl. XXVI. fig. 7), Pewocephalus riippelli, and Pawocephalus
robustus the origin of the muscle extends almost to the posterior extremity of the
hypobranchial; in both, the bifid tendon is similar to that in Kelectus, but it ts
not so strongly developed, and less so in Paocephalus than Paleornis. In Ptistes
erythropterus the muscle is similar to that in Pwocephalus, but its origin only extends
halfway along the hypobranchial.

Eclectus pectoralis.—Dorsal view. The trachea (T.) has been turned to the right and only sufficient of the
stylohyoideus (st.h.) left to show its insertion. (Twice nat. size.)

Additional letters.

g. = glottis. th.g. = thyroglossus. th.h.a. = thyrohyoideus
th.h. = thyrohyoideus. accessorius,

In Platycercus eximius (Pl. XXVI. fig. 11), Pezoporus formosus (Pl. XXVI.
fig. 8), Prioniturus sp.%, Cyanorhamphus auriceps, and Tanygnathus miillert the tendon
of insertion is bifid and is similar to that in Conurus jendaya, but its anterior portion
is more or less distinctly cylindrical and slightly elongated, and it foreshadows the
markedly cylindrical tendon of the Loriide (Pl. XX VII. fig. 21, ten.).

In Psittacula passerina, Caica leucogaster, and Bolborhynchus lineolatus the muscle
arises from the anterior third of the hypobranchial and is inserted by a cylindrical
tendon to the mesoglossus ; the tendon is not bifid.

939 MR. G. P. MUDGE ON THE MYOLOGY

In Lovins domicella (Pl. XXVII. fig. 21) the muscle attains its highest develop-
ment, its origin extending along the whole length of the hypobranchial and at the
posterior extremity of which it is slightly tendinous. Along the posterior two-thirds
of its hypobranchial connection it is fused with the dorsal surface of the ceratoglossus
inferior posticus. In the basihyal region it splits into a smaller ventral layer (cq.ss.),
and a larger dorsal one (cq.s.), of which the former has its origin from the basihyal and
the latter from the hypobranchial. The condition of the divided muscle is foreshadowed
in Pyrrhulopsis (cf. ante, p. 280). Anteriorly the two pairs of muscles become
confluent and merge with an elongated markedly cylindrical tendon (¢en.) that inserts
them to the mesoglossus ; the tendon lies immediately ventrad of the symphysis of
the parahyal arch. In Vint australis the muscle is similar to that in Lorius domicella,
but the ceratoglossus subsuperior (cq.ss.) is more strongly developed and extends back
as far as the base of the urohyal; the muscle is merged with the ceratoglossus inferior
posticus at its posterior extremity only. In Lorius flavo-palliatus and Eos riciniata
there is no splitting of the muscle; in other respects it is similar to that of
L. domicella.

In Nestor notabilis (Pl. X XVII. fig. 22) the muscle arises from the anterior third
of the hypobranchial and the two halves remain distinct throughout; their tendon is
fiat and elongated and extends forward to the anterior extremity of the tongue, where
it becomes connected with the tendons of the hypoglossus rectus and with the covering
membrane of the tongue. This elongated tendon probably represents in part the fascia
cf the mesoglossus; for in Nestor the mesoglossus muscle itself has disappeared.

THYROHYOIDEUS AND 'THYROHYOIDEUS ACCESSORIUS MUSCLES.

The thyrohyoideus, apart from its connection with the thyroglossus, exhibits very
constant characters in all the Parrots examined. In the majority of them it arises
from the anterior portion of the parahyal process and is inserted into the ventro-
lateral surface of the thyroid. In some it gives off upon its inner side a small
muscular branch, but as this is a rudiment of the thyroglossus, variations of this sort
will be considered under that muscle.

In Cacatua roseicapilla and C. galerita (Pl. XXVIL fig. 13, th.h.) the muscle exhibits
the most primitive condition, and there is given off from the ventral edge of the thyro-
hyoideus a relatively large branch (th.h.a.) which is attached to the basihyal at the base
of the urohyal; in other Parrots this becomes more or less separated from the parent
muscle, and I propose to speak of it as the thyrohyoideus accessorius. It is slightly
smaller in C. roseicapilla than in C. galerita. In C. leadbeateri the accessory muscle
is smaller, but it is partially divided into two anteriorly, and the posterior of the two
branches thus formed has shifted its origin to the head of the hypobranchial. In
C. alba, Calyptorhynchus funercus, and Calyptorhynchus banksi the muscle is like that
in C. leadleatcvi, but the posterior branch of the accessory muscle arises from the basi-

bo

OF THE TONGUE OF PARROTS.

hyal near the root of the urohyal; the accessory muscle is much more strongly
developed. ‘The muscle in C. triton is like that in @. alba, but the division of the
accessory muscle is not so well marked and appears to be incipient rather than actual.
In addition, there is present on the left side a very narrow muscle that arises from the
extremity of the cartilaginous continuation of the urohyal and is inserted into the
fourth tracheal ring; in its origin and narrowness it resembles a similar muscle in
Eclectus (text-fig. 7, th.h.a., p. 231), but differs from it in its insertion. In C. swlphurea
the thyrohyoideus is divided into two, the anterior division arising from the apex
of the parahyal process and the posterior one from the posterior half; both are inserted
into the ventro-lateral surface of the thyroid. The thyrohyoideus accessorius consists
of two divisions, the origins of which have been shifted forward to the cylindroidal
portion of the basihyal and are inserted to the posterior end of the thyroid. The
muscle is therefore more complex than in other species of Cacatua, and the origin of
the accessory muscle is much more anterior. In Calopsittacus nove-hollandie the
muscle resembles that in Cacatua alba, but the accessory muscle is divided into four
narrow bundles, the collective origin of which is nearly the same as that of the two
bundles in C. alda, but has a slightly more posterior extension, since the hindmost
two of the four arise from the lateral surface of the anterior end of the urohyal.

In Leclectus pectoralis (text-fig. 7, p. 231), Peocephalus robustus!, and Nasiterna
pusio, the accessory muscle exhibits an unusual arrangement. It is very narrow, and
arises, not from the basihyal, but from the posterior extremity of the urohyal, and is
inserted at the anterior end of the thyroid. In Nasiterna it widens very much at its
insertion. In Stringops habroptilus (Pl. XXVII. fig. 18) and Microglossus aterrimus
the accessory muscle (¢h./.a.) is quite separated from the parent one, and its origin is from
the posterior edge of the basihyal and the outer margin of the urohyal; its insertion
is partly to the posterior border of the thyroid and partly to the first tracheal ring
behind that. In Microglossus the thyrohyoideus extends forwards beyond its origin
at the parahyal process as a small muscular tract, which forms a second origin at the
posterior extremity of the entoglossum; the tract on the right side is about three
times as large as that on the left. In Nestor notabilis (Pl. XXVII. fig. 22) the thyro-
hyoideus arises from the posterior two-thirds of the parahyal arch and to a small
extent from the dorsal surface of the body of the hyoid; the extension of the origin
backwards on to the basihyal is suggestive of one of a primitively more extensive nature.
The thyrohyoideus accessorius is like that in Stringops and Microglossus, except that
at its origin the muscle is narrowed. There is also present a muscle which I have not
found in any other Parrot: it arises from the sheath investing the urohyal, turns out-
ward and runs over the surface of the ceratohyoideus, round the lateral ceratoglossal
to the dorsal surface of the tongue, thence over the sternohyoideus and thyroglossus

1 But not in P. riippelli.

234 MR. G. P. MUDGE ON THE MYOLOGY

to the edge of the glottis, into the anterior two-thirds of which it is inserted. It has
advanced very far in its retrogression, and consists only of the fascia with a few
muscular fibres; I shall speak of it as the thyrohyoideus accessorius transversalis
(Pl. XXIX. fig. 46, th.h.a.t.).

In all the species of Conurus, Chrysotis, Ara, Deroptyus, and Cyanolyscus the muscle is
narrow at its origin and widens at its insertion. In Conwrus jendaya (Pl. XXVI, fig. 9)
and C. holochlorus the muscle is merged with the thyroglossus at its posterior end!; in
Cyanolyseus patagonicus and Pyrrhura leucotis (Pl. XX VII. fig. 19) the confluence is
greater, and in Conurus cactorum the two muscles are represented by a single one with
a double origin, which is very similar to that in Brotogerys (text-fig. 9, p. 258, th.h.,
th.g.). In Chrysotis, Deroptyus, and Ara the muscle, though lying in contact with the
thyroglossus in its posterior region, is not confluent with it at any part. In Ps?ttacus
(Pl. XXVII. fig. 15) and Coracopsis (Plate XX VII. fig. 17) the thyrohyoideus is
hidden by the thyroglossus, which overlies it somewhat dorso-laterally, and in the latter
bird it is narrowed at its origin. In Psittacula and Pezoporus(Pl. XXVI. fig. 8) there
is a like condition, but the thyroglossus lies wholly dorsally to the thyrohyoideus. In
Palwornis (Pl. XXVI. fig. 7) the thyrohyoideus is very thin and narrow ; it is slightly
stouter in Tanygnathus ; and in Loriculus galgulus (Pl. XXVII. fig. 23), in addition,
it narrows very considerably at its insertion. In Bollorhynchus the relation of the
muscle to the thyroglossus is similar to that in Platycercus (Pl. XXVI. fig. 11), but it
is confluent with that at its origin and insertion, and separated in the intervening
portion of its course. In Pyrrhulopsis splendens and P. personata the thyrohyoideus
arises from the inner surface of the parahyal process anterior to the insertion of the
stylohyoideus on the outer surface ; in most Parrots the two muscles are attached
opposite each other.

In Cyanorhamphus, Prioniturus, Caica, Ptistes, Nymphicus, and Psephotus there are
no special features worthy of notice.

In Pionopsittacus pileatus a thyrohyoideus is absent. In Pstttinus incertus the
muscle is also absent, unless one which has the insertion of a thyrohyoideus, but the
origin of a thyroglossus, be regarded as the muscle which has changed its origin.

The absence of the muscle in Pionopsittacus and its attenuation in others would
seem to indicate that in some it is undergoing retrogression.

In Lorius domicella (Pls. XX VII. & XXIX. figs. 21 & 50) and L. flavo-palliatus the
muscle arises from the anterior end of the crura of the parahyal arch, immediately
behind the hypocleidium, and is inserted in a somewhat oblique fashion into the dorso-
lateral surface of the thyroid, being covered at its insertion by the thyroglossus. In
Eos riciniata the muscle is similar in its relations, but it is confluent at its origin with
the thyroglossus. In Vint australis the muscle is confluent both at its origin and
insertion with the thyroglossus, though free elsewhere.

1 The artist, however, has represented the two muscles as distinvt at their posterior extremity.

i)
(Se)
on

OF THE TONGUE OF PARROTS.

Tuyroaciossus Muscle.

The condition which this muscle exhibits is interesting. Its evolution starts from
three distinct initial stages, all of which meet at a higher stage by convergence, and
thence pass to the still higher ones by a common road. The evidence shows that
the thyroglossus has arisen from the thyrohyoideus, and that it has done so by three
methods: (A) the thyroglossus arises as a branch which separates from the thyro-
hyoideus as soon as the plane of division is formed, the latter commencing at the
anterior end and gradually extending posteriorly ; (B) the plane of division is formed
in the parent muscle (thyrohyoideus), but the thyroglossus does not immediately
separate from it; (C) the thyroglossus arises as a forward extension of a portion of
the thyrohyoideus, which grows forwards to form an origin at the entoglossum without
first separating from the parent muscle.

Method A.

Stage 1.

Cacatua roseicapilla and Cacatua leadbeateri exhibit the first stage by this method.
In these birds the muscle is represented by a small branch separating from the anterior
portion of the thyrohyoideus ; the branch has lost its origin at the parahyal process
and its free extremity does not extend beyond the level of the anterior extremity of the
thyroid; the branch is slightly larger in C. leadbeatert than in C. roseicapilia.

Stage 2.

In Cacatua galerita (Pl. XX VII. fig. 13, th.g.), Calopsittacus, Microglossus, Chrysotis
ochrocephala (Pl. XXVII. fig. 12, th.g.), Chrysotis westiva, Eclectus pectoralis (text-fig. 7,
p. 231), and Nestor notabilis (Pl. XX VII. fig. 22, th.g.) the muscle has separated along its
whole length from the thyrohyoideus, though still in contact with it, while its free
extremity has grown forwards and towards the middle line, and lies in the entoglossal
space, well in front of the apex of the thyroid. This stage is thus in advance of the
first, in that the muscle has quite separated from the parent one, and in its growth
forwards anterior to the apex of the thyroid. Chrysotis panamensis belongs to this
stage, but the muscle (P]. XXVII. fig. 14, th.g.) at its free extremity is connected with
a twig of the sternohyoideus and is confluent with the extremity of its fellow of the other
side.. This latter condition, or one in which the free extremities of the muscle of either
side are in contact, is present in all the Parrots belonging to this stage. But the
connection with the sternohyoideus is peculiar, and it is to be noted that the latter
is retrogressing—only its fascia remains—at its junction with the thyroglossus. In the
absence of a better explanation, we may regard it as an illustration of the tendency to
retain old associations, and may assume that in the primitive condition of the muscle,

VOL. XVI.—PART V. No. 4.—October, 1902. 2M

236 MR. G. P. MUDGE ON THE MYOLOGY

when as an incorporate part of the thyrohyoideus it arose from the apex of the
parahyal process, opposite to the insertion of the sterno-hyoideus, the extremities
of the two muscles were more or less confluent, as they are actually in Conurus
holochlorus (infra, p. 240); when the thyroglossus began to separate from the thyro-
hyoideus and to give up its origin at the parahyal process, it is probable that it carried
forward with it a portion of the sternohyoideus.

Chrysotis viridigena stands on the borderland between stages 2 and 5. The muscle
is similar to that in Chrysotis ochrocephala, but its free extremity is connected to the
middle part of the inner surface of the entoglossum, not by tendon or a prolongation
of its own substance, but by a definite tract of connective tissue; this tract foreshadows
the actual growth forwards of the muscle itself to the entoglossum, such as has
occurred in stage 3.

Method B.

Stage 1.

Coracopsis vasa is the sole representative of this stage by this method. ‘The thyro-
glossus (Pl. XXVII. fig. 17, th.g.) is separated from the thyrohyoideus along its whole
length ; but the course of the two muscles is coincident, their origins and insertions
are almost the same. An earlier stage, 2. €. one in which the thyroglossus is more or
less confluent with the thyrohyoideus (only partially separated from it), is not represented
in this method. But in view of the mode of origin of the muscle by Method A, and
of the intimate relations of the two muscles here, we are justified in the assumption
that the thyroglossus of Coracopsis has arisen in the same way, by becoming split off
from the thyrohyoideus. But in this instance the separation of the two muscles has
been completed, and yet the old origin at the parahyal process is retained.

Stage 2.

In Stringops (Pl. XXVII. fig. 18) the muscle is similar in its relations to the thyro-
hyoideus to that in Coracopsis, but it gives off a very small twig (th.g!.) from its inner
side, which is confluent at its extremity with a forwardly directed twig of the stylo-
hyoideus and with the extremity of its fellow of the other side. Stringops thus exhibits
the first beginning of stage 2, 7. ¢. the gradual rejection of its primitive origin after the
splitting off of the muscle from the thyrohyoideus. The connection of the twig with
the sternohyoideus is probably accidental and due to the same cause as the somewhat
similar arrangement in Chrysotis panamensis (ante, p. 235). In Psittacus (Pl. XXVIL.
figs. 15 & 16) the muscle is like that in Stringops, but the internal twig (th.g1.) is much
larger and nearly as large as the body of the muscle, and there is no connection with
the stylohyoideus; thus its recession from the primitive origin has progressed to a

OF THE TONGUE OF PARROTS. Diol

greater extent. In Calyptorhynchus funereus (probably also in C. banksii, where the
muscle was injured before the tongue came into my possession), Cacatua alba, Cacatua
triton, and JVasiterna the muscle is similar to that in Psittacus. In Wasiterna, how-
ever, the twig (th.g!.) does not become confluent with its fellow of the other side, but
lies, with no definite attachment in the entoglossal cavity, just beneath the membrane
of the tongue. In Cacatua triton the twig of either side also branches at its extremity,
which thus becomes bifid; this condition foreshadows the peculiar one seen in
Peocephalus riippelli and Ptistes (Plate XXVI. figs. 6 & 10). In Cacatua
sulphurea (text-fig. 8) the twig is continuous with a trifurcate tendinous structure, one

Text-fig. 8.

Oacatua sulphurea.—Dorsal view of thyroglossus. Semi-diagrammatic, (Nat, size.)

KE. = entoglossum.
T. == trachea.
P.P. = apex of parahyal process.
th.g. = larger outer branch of thyroglossus.
th g'. = smaller inner branch of thyroglossus, which on the
right-hand side was injured in dissection.
a, 3, y = tendinous branches of th.g’.

g. = glottis.

prong («) of which is attached to the entoglossal of the same side of the tongue, one (/3)
to the entoglossal of the other side, and the other (y) to the parahyal process of the other
Doubtless there is a similar arrangement for the muscle of the other side, but
To some extent this condition is similar

side.
it was unfortunately injured in dissection.
to that in Pwocephalus and Ptistes; but 1 prefer to place it in this stage rather than
with either of them, because the aforesaid tendinous prolongation of the muscular twig
‘s not such a definite structure as that which apparently represents it in them, and

may probably be an individual variation.
9 sy
2M 2

238 MR. G. P. MUDGE ON THE MYOLOGY

Method C.

Stage 1.

In Brotogerys pyrrhopterus (text-fig. 9) there is but a single muscle to represent both
the thyroglossus and thyrohyoideus. It has a double origin, in part from the inner
surface of the posterior half of the entoglossum (E.N.) (= origin of thyroglossus in
certain other Parrots) and in part from the inturned apical portion of the parahyal

Text-fig. 9.

— oe Toot
Sa YS

I)

)

)

my)

@)

#.

Brotogerys pyrrhopterus.—Dorsal view of thyrohyoideus. (I'wice nat. size.)
E.N. = entoglossum.
P.P. = parahyal process.
th.h. = thyrohyoideus.
mg!, = tissue identified as mesoglossus.
T. = trachea.
th.g. = the forward prolongation of th.h.,and which in other
Parrots becomes separated as the thyroglossus.

process (P.P.) (= origin of thyrohyoideus in all Parrots). Its insertion is upon the
dorso-lateral surface of the thyroid. The muscle of either side is confluent with its
fellow in the middle line in front of the glottis.

In Conurus cactorum the condition of the muscle is similar to that in Brotogerys,
except that the insertion extends ventrally on to the ventro-lateral surface of the
thyroid; the representation of the muscle for Conurus jendaya (Pl. XXVI. fig. 9)
would do for C. cactorum if the plane of division there indicated between the thyro-
glossus and thyrohyoideus were not present.

bo
oo
eo)

OF THE TONGUE OF PARROTS.

Stage 2.

In Pyrrhura leucotis (Pl. XX VIL. fig. 19, th.g.) the muscle is similar to that in Conurus
cactorum ; but there is an incipient plane of division existing between that part of the
muscle arising from the parahyal process (= thyrohyoideus) and that part arising from
the tendon of the hypoglossus obliquus immediately behind the posterior extremity
of the entoglossum (= rudimentary thyroglossus) In Cyanolyseus patagonicus and
Conurus jendaya (Pl. XXVI. fig. 9) this incipient division extends backwards, in
the latter Parrot almost to the posterior end of the muscle, so that there is now
formed a definite and independent thyroglossus, having a separate origin of its own,
but merged at its insertion with the posterior part of the thyrohyoideus. The extent
of the division in Cyanolyseus is intermediate between that in Conurus jendaya and
C. cactorum.

‘Thus this method is characterized by the fact that the parent muscle (thyro-
hyoideus) first grows forwards beyond its origin on the parahyal process and forms a
second one at the entoglossum (Brotogerys and C. cactorum); then an incipient plane
of division arises anteriorly, which lies between the part of the muscle arising from
one origin and that from another (Pyrrhura) ; and, finally, this plane of division
becomes more perfect, almost dividing the parent muscle into two independent parts
(Conurus jendaya and Cyanolyseus). The next stage would be that in which the
division is complete and would result in the formation of two independent muscles,
producing a condition coucerning which it would not be possible to say whether it had
arisen by one method or the other. Such a condition we will now consider.

The Convergence of Methods A, B, C.
Stage 3.

The result of the evolution of the thyroglossus by either Method A or B is to
produce a muscle which has wholly or in part lost its origin, and whose free extremity
lies in or near the middle line in front of the thyroid; Chrysotis viridigena (ante,
p- 236) in Method A foreshadows the further evolution of the muscle, and indicates
that the entoglossum is destined to constitute the new origin. In Method B there is
nothing to definitely indicate the future origin of the muscle which is withdrawing from
the old one, but the & priori probability is that it will be the same as in Methods A
and C. In Method C the entoglossal origin is reached at once before the definite
formation of the muscle that is to arise from it has taken place. In all three Methods
two stages in the evolution of the muscle may be discerned, and the third stage (that
now to be described) is common to all.

The characters that distinguish this stage are: the entoglossal origin and the
complete separation of the thyroglossus from the parent muscle (thyrohyoideus). The
entoglossal origin is common to this stage and the two stages in Method C, but they

240 MR. G. P. MUDGE ON THE MYOLOGY

are distinguished in the complete separation of the two muscles in the stage now under
consideration.

In Palwornis torquata (Pl. XXVI. fig. 7, th.g.) and Tanygnathus miilleri the muscle
arises from the inner surface of the entoglossum a little anterior to its posterior extremity,
and is inserted at the dorso-lateral surface of the thyroid; it is narrow at its origin,
but very wide at its insertion. In Loriculus galgulus (Pl. XXVII. fig. 23) the muscle
is like that in Palwornis, but it arises from the posterior extremity of the entoglossum.
In Ara ararauna the muscle is similar to that in Palwornis, but it is much attenuated.
In Ara macao (Pl. XXVII. fig. 20) the muscle is well developed and arises from the
tendon of the hypoglossus obliquus just posterior to the origin of the latter from the
posterior extremity of the entoglossum; its insertion is for the most part to that
portion of the membrane (m.) of the tongue that covers the thyroid on either side of
the glottis, and also to a small extent to the upper margin of the dorso-lateral surface
of the thyroid. In Pionopsittacus pileatus the muscle resembles that in Paleornis,
but its origin is tendinous. In Psittinus incertus the muscle appears to be double.
It consists of two perfectly distinct parts closely bound together by connective
tissue, which arise from the posterior extremity of the entoglossum, and become
inserted, one to the dorso-lateral surface, and the other to the ventro-lateral surface
of the thyroid. The former of these parts is undoubtedly a thyroglossus, and the
latter, in virtue of its insertion, is a thyrohyoideus, but a thyroglossus on account of
its origin: probably it is a thyrohyoideus that has acquired a new origin, and we
can understand how, if old associations tend to be preserved and the thyroglossus arose
by Method C, that it was carried forward to the entoglossum.

In Ptistes erythropterus (Pl. XXVI. fig. 6) the condition that is foreshadowed in
Cacatua triton (ante, p. 237) has attained its full development, for the rudimentary
bifid nature of the free extremity of the muscle there indicated has in Ptistes developed
into a well-pronounced fork of two prongs, the larger of which has formed a tendinous
origin at the inner surface of the posterior lateral process of the entoglossal of the
same side of the tongue, while the smaller one crosses the middie line and reaches its
origin at the same position on the entoglossal of the other side.

Stage 4.

In this stage the muscle is characterized by having a double origin, z. e. one from
the entoglossum and another, more or less strongly developed, from the parahyal
process.

In Deroptyus accipitrinus that part of the muscle which arises from the entoglossum
is very much the stronger of the two, and in fact constitutes almost the whole of the
origin ; the part arising fromthe parahyal process consists of only a few fibres. The
insertion is the usual one. In Conurus holochlorus the two origins are more nearly
equal, that at the entoglossum being slightly larger than the other; the part arising

OF THE TONGUE OF PARROTS. 241

from the parahyal process is confluent with the tendon of the stylohyoideus at its
insertion on the apex of the parahyal process.

In Peocephalus riippelli (Pl. XXVI. fig. 10) the entoglossal portion (¢h.g!.) of the
muscle is split into two branches, and is similar to that described for Ptistes (ante,
p. 240). Of the two branches, the smaller one takes its origin from the entoglossal
of the same side, while the much larger one passes over to the entoglossal of the other
side, and arises from this at its posterior extremity by an origin common to it and
the smaller branch of the muscle of the other side. Thus the muscle at its origin from
the entoglossal of either side consists of two sets of fibres: of a larger set derived
from the muscle of the other side and a smaller set derived from the muscle of the
same side; the fibres of the two muscles are thus distributed and cross each other in
precisely the same way that the nerve-fibres of the optic tract of mammals do. The
parahyal portion (¢h.g.) of the muscle is smaller than the combined entoglossal portion.
In P. robustus there is the same general arrangement and optic-chiasma-like condition
of the muscle; but the parahyal portion is larger than the entoglossal, and the larger
branch of the entoglossal part belongs to the same side and the smaller to the other
side, which is just the reverse to that in P. riippelli.

The condition which the muscle exhibits at this stage (Stage 4) may be interpreted
in two ways: either the parahyal portion is retaining, to a greater or less extent,
its primitive relation to the parahyal process, or, it is secondarily coming back
to it after it had attained a wholly entoglossal origin. It is necessary to decide, as far
as possible, which of these two alternatives is the more probable; and since the answer
depends upon the condition of the muscle in the later stages of its evolution, I shall

proceed first to their description.

Stage 5.

The relations of this muscle at this stage are somewhat similar to Stage 1 in Method B.
It arises from the apex of the parahyal process, and is inserted into the dorso-lateral
surface of the thyroid. It thus corresponds in its origin, and nearly so in its insertion,
to that in Coracopsis, which I have placed at a much earlier stage; but there is a
difference—which, however, does not hold true in ail cases—in that at this stage the
insertion of the thyrohyoideus is distinctly ventrad of the thyroglossus, whereas in
Coracopsis the two muscles run an almost coincident course, not only at their insertion,
but along their whole length. The further reasons that have induced me to consider
similar conditions as belonging to two distinct stages I shall mention later (infra,
p. 243).

Platycercus eximius (Pl. XXVI. fig. 11, t/.g.) may be taken as typical of this stage ;
the thyroglossus arises from the apical region of the parahyal process dorsad of that of
the thyrohyoideus, and retains this position with respect to the latter muscle along its
whole course, including its insertion. If it be compared with that of Coracopsis
(Pl. XXVII. fig. 17) the difference in its relation to the thyrohyoideus is apparent, for

942 MR. G. P. MUDGE ON THE MYOLOGY

in Platycercus it is situated dorsally and in Coracopsis laterally to that muscle. In
Psephotus wanthorrhous, Nymphicus wowensis, Caica leucogaster, Prioniturus sp.?,
Cyanorhamphus auriceps, Pyrrhulopsis splendens and P. personata, Psittacula passerina,
and Pezoporus formosus (Pl. XXVI. fig. 8) the muscle is similar to that in Platy-
cercus. In Bolborhynchus lineolatus the muscle is similar to that in Platycercus, but
it is confluent at its origin, and along its ventral border at its insertion, with the
thyrohyoideus; along the remainder of its course it is free of that.
Stage 0.

In this stage the muscle arises from the hypocleidium (apex) of the completed
parahyal arch, and is inserted into the dorso-lateral surface of the thyroid (Pls. XX VII.
& XXIX. figs. 21 & 50). It thus differs in respect of its origin from that in Stage 5,
in that it arises from the median projecting process formed by the union of the
parahyal crura (cf. Mivart, P. Z.S. 6 & 7), instead of from the parahyal processes.
Although the muscle (Pl. XXIX. fig. 50) lies dorsally to the thyrohyoideus along the
major portion of its course, the latter muscle at its insertion turns upwards and, passing
between the thyroglossus and the thyroid, becomes inserted into the dorso-lateral
surface of the latter. In Kos riciniata the thyroglossus is merged with the thyro-
hyoideus at its origin, but otherwise is similar to that in Lorius. In Vini australis the
muscle is confluent with the thyrohyoideus both at its origin and insertion. The
confluence of the two muscles in these two genera at these particular parts must not
be regarded as indicating a primitive condition, for it is probable that this confluence
is secondary, and arises from the fact that in these aree the two muscles are in
contact.

A survey of the variations presented by this muscle thus substantiates the statement
made (ante, p. 235) that it started along the road of its evolution from three initial
stages, all of which ultimately lead to a common stage, the third stage in the evolution
of the muscle. Cacatua roseicapilla and C. leadbeateri belong to one of these initial
stages, Coracopsis to another, and Brotogerys and Conurus cactorum to the other.
Each of these initial stages passes along its own line of development to a second, and
each of these converges to a third stage, which is similar in all. This latter stage is
characterized by the entoglossal origin of the muscle, and it appears to be, like those
that preceded it, but a temporary one, for the muscle, having left the parahyal
process to extend to the entoglossum, begins to return to its primitive origin. The
first step in that return is indicated in Deroptyus accipitrinus, where the origin
of the muscle is double; the greater part arises from the entoglossum, but a few
fibres, however, take their origin from the parahyal process. I interpret the parahyal
origin as representing the first return of a few fibres back from the entoglossal origin.
In Conurus holochlorus a greater number of fibres have returned, and the two origins
are nearly equisized. ‘The condition of the muscle in Pwocephalus is fundamentally
the same, but its entoglossal portion has specialized in its own direction. From this

OF THE TONGUE OF PARROTS. 243

stage, which constitutes the fourth one, to the next is somewhat sudden, since in Stage 5
the whole of the remaining portion of the muscle has returned to the parahyal process.
In the final stage, owing to the formation of a completed parahyal arch, by the growth
forwards and meeting in the middle line of the parahyal processes, with the formation
of a median symphysis, the hypocleidium, the muscle arises not from the crura, but
from the hypocleidium.

It may be objected that the interpretation of the facts represented in Stage 4 implies
that the origin from the parahyal process is at once the most specialized and the most
primitive condition. Such an objection would be quite valid were it not that other
facts in the lingual myology support the conclusion arrived at by the consideration of
those relating to the thyroglossus; and, moreover, there is a difference between the
two stages with respect to the insertion and the general course of the muscle in relation
to the thyrohyoideus (cf. ante, p. 241). If we arrange in two columns those Parrots
in which the thyroglossus arises from the parahyal process—in one column those which
my interpretation of the facts lead me to regard as primitive, and in the other those
which I regard as specialized—the divison will be as follows :—

it, | I,
PrimitIve, | SPECIALIZED.
SESS |
& 28 5 } Coracopsis. Eos.
ee
Hie
BS be ( Psittacus. Vim.
So : :
2 | Stringops. Lorius.
=z GOK
QR .
23 ! Cacatua alba. Caica.
gES<
Say » triton. Cyanorhamphus.
3 F | Nasiterna. Nymphicus.
o
ne \Calyptorhynchus. Platycercus and some other
members of Stage 6.

Now a glance at the table of characters (pp. 266-269) of the inferior ceratoglossus
will show that those Parrots in which I regard the parahyal process origin of the
thyroglossus as secondary (column II.), and as distinct from those in which I regard
it as primitive (column I.), are, in virtue of the characters of that muscle, very much
specialized: some of them, in respect of the tendon and the amount of retrogression of
the ceratoglossus inferior anticus, are more advanced than others, but all of them have
reached their fullest development with regard to the extension posteriorly along the
hypobranchial of the ceratoglossus inferior posticus. It is very different, however,
with the inferior ceratoglossus of those Parrots arranged in column I.: four of the

VOL. XVI.—PaRT Vv. No. 5.—October, 1902. 2N

244 MR. G. P. MUDGE ON THE MYOLOGY

seven belong to the most primitive stages, and the other two are not very much more
advanced. And it is interesting to note that Deroptyus and Conurus holochlorus,
although placed with Psittacus and Coracopsis in respect of the character of the
inferior ceratoglossal tendon, are intermediate between them and the members of
column II. in the remaining characters of that muscle, which is a position they should
occupy if my interpretation of the nature of the parahyal fibres of their thyro-
glossus muscle is correct. In Peocephalus, the thyroglossus of which, according to
the meaning here attached to it, is the most advanced of Stage 4, the characters
of the inferior ceratoglossal are identical with those of some of the Parrots in
column II.

To state the facts in a briefer form, we may say that there are two sets of Parrots
with a parahyal process origin for the thyroglossus. In one of these sets the cerato-
glossus inferior is primitive and in the other specialized. Hence has arisen the
conclusion that the parahyal process origin in the one case is primitive and in the other
secondary. And, seeking for a logical demonstration of the truth of this conclusion,
we must find a Parrot which in respect of its ceratoglossus inferior must be inter-
mediate between the two sets of Parrots, and in the characters of its thyroglossus
must show the transition from the entoglossal origin—which has been traced from
the primitive parahyal process stage—to the secondary parahyal process stage: such
Parrots are Deroptyus, Conurus holochlorus, and Peocephalus; and they exhibit, as far
as the first half of the gap, a graded series.

The conclusion is further corroborated bya consideration of the amount of extension
of the hypoglossus obliquus. In those Parrots in which I regard the thyroglossus
origin at the parahyal process as being primitive, the hypoglossus obliquus is limited
to the head of the hypobranchial, and in two instances only extends back along that
through the anterior third; but in those in which the parahyal process origin is
secondary the hypoglossus obliquus extends backwards along the whole length of the
hypobranchial in the majority of instances, and in only a few as far as the anterior
two-thirds.

If the conclusion that the parahyal process origin of Stages 5 and 6 of the thyro-
glossus is not accepted, the only other alternative is to believe that this muscle has
remained primitive in Parrots in which other muscles have advanced to a specialized
condition, and that it has advanced to more or less specialized conditions in Parrots
in which other muscles have remained primitive or have advanced but slightly.

The evolution of the muscle is graphically represented in the following Table :—

245

OF THE TONGUE OF PARROTS.

"SUDLISND UA
DIDULIVL SOIT

‘sngoyjnd-oanyf
“DIIOUWOP SNOT

‘muniplopod Ay Woy sastay snssopFort yy,

*9 08%1S
9) ssnary dueling *snawaohgnn
“‘pynanyDST *sasdopnylah ‘snyouliysoguog
ssnydunycouvhy ssnwodozag “STL JIU T

‘ssoooad pudtpeavd wor sostav sussopsoakpy,
*"g o8NIg

| P

*S77SNQOuL ss *SLO]YIOJOY SN.0NU0D
“ypjaddns snynydo00nq ssnhijpdoway
‘ssoooad pudyuard woay qaud ur puv wnssopsozua woay avd ur sosi.ce snssopso.tdt gy,
‘'D e3vig
"8998097 “SNUDIQIST ‘punnapan
*snynaIoT “phinpual snunuoy OnIDUL DLT
‘snonjgysdouony, ‘snypoubliunT, ‘puabhrprua syoshia 9

‘snoprosyorhyy oy} TWO pozeredos

‘£yayoTdunoa ysowmye to ‘Kpoyopdtuoa st puv ‘tunssopFoyua oyz woIy sastie snssopsothyy,

*“DULIQISDAT
UG}? DNADIDI

‘sdohurgg
“sronypisd.

“nq7v VnIVIDI
snyouliyopdhpyg

‘ssooaad pedqvand
ol} MOF MLAPYILA 07 Surwurseq sr snssopsosdyy ONT,

"g 03R1S
*sisdoaD.loy

‘ssonoad pedyrard
qv WLIO data s]r sUINZot [[8 snssopso.1hT} oT],

‘T 0301S

‘PoULAOF SVL UOISIATP Jo ounTd v L92/
£ieuprsd snaprosyoakyy wo. soyvavdes snssopsoadTp J,

Se

"€ o8rIg

a

“WOSINT wyoydoo0.ayI0 srg0shtyD

“SR g09)0T *snssophowouyy

‘sesuampuvd ss *snanggisdoj0Q
“OAUSD SY0ShLYD “mpuaoh wngnong
“proriy} Jo yuoay ur [Jaa sory snssopsorduy Jo Aqru0ayxXqq

"eZ 0201S

“mpdonaso. nnjIDIVD
“pro. ky Jo yuoaz
UL A] JOU soop snssopso1dyy Jo AyruteA9X9 VaAJ OT,

‘T 03%1g

“DaqwIgpyay DnanInD

‘snoproktpoadtyy tuoaz oot Yu Yo soyouvaq snssopsoacyT,

ee

ssnaproliyowhy,T,

‘snashjounhig spiny

‘snaprokqoadtyy toay
snesopSor6y} oy} soyeavdos uorsiarp perqaed jo ourfd y

"Z O3e1S

*UNLOJIDI SNLNUOD)
‘T o8%1S

‘tnssop soya oY} 0} snoprokyorsty Jo
uorpesuofoad pavartoy qootip v sv sasi.te snssopso.ckyy,

sshiahopouge

‘CUINASUUAAU ATVIVOMIdVUD ‘SASSOTDOUAILT, GUL FO NOMATOAY ANT,

fo]

2N

246 MR. G. P. MUDGE ON THE MYOLOGY

Tus Hypociossus Muscin.

(a) LHypoglossus obliquus.—Vhe variations exhibited by this muscle may be considered
under three heads: Ist, the amount of its extension backwards upon the hypobranchial ;
2nd, the degree of development of its tendon or tendinous fascia; 3rd, its divided or
undivided condition. The advance of an individual muscle in respect of any one of
these characters is not always accompanied with a corresponding advance of the other
two; but if the muscles are arranged in sets, each set representing a stage in the
progression of one of these three characters, it will be found that the majority in each
set are advanced in respect of the other two characters.

The muscle arises in part from the hypobranchial and in part from the ventral and
dorsal surfaces of the body of the basihyal, and is inserted into the inner surface and
posterior margin of the posterior lateral process of the entoglossum. In some Parrots
(Pls. XXVIII. & XXIX, figs. 29 & 48) (cf. pp. 266-269) the muscle (/g.0.) is divided
into two in a longitudinal direction, in such a way that an outer portion related to the
hypobranchial is separated from an inner one related to the basihyal, both retaining
the origin insertion. Bat in Lorius the plane of division does not thus divide the

muscle, for the outer portion is related both to the hypobranchial and basihyal
(Pl. XXIX. fig. 37).

Stage 1.

The most primitive condition of the muscle is that in which its origin is almost
wholly confined to the basihyal, and posteriorly does not extend farther than to the
anterior head of the hypobranchial; it is further generally characterized by the absence
of a tendon or tendinous fascia and by the fact that it is not divided into two portions.
(Cf. the table of characters of Hypoglossus obliquus, pp. 266-269.)

Stage 2.

In this stage the muscle has extended backwards as far as the anterior third or
half of the hypobranchial. The fascia is usually tendinous or a weak tendon is
developed; but in some few instances (JVestor) a strong tendon is present. ‘The
muscle is divided in about 50 per cent. of the Parrots.

Stage 3.

The muscle extends to the anterior two-thirds of the hypobranchial, and in most
instances the tendon is fairly strongly developed, and in a few strongly; in one
(Deroptyus) it is absent, and neither is the fascia tendinous. The muscle is divided
in all except three.

Stage 4.

This is the final stage, and it is marked by the extension of the muscle to the

posterior extremity of the hypobranchial; in all instances the tendon is strongly

developed, and in a few instances yery strongly so. ‘The muscle is divided in all, with
but two exceptions.

OF THE TONGUE OF PARROTS. 247

(3) Hypoglossus rectus.—This muscle (hg.r.) arises from the outer surface of the
posterior lateral process of the entoglossum and is inserted tendinous partly into the
apex of the tongue and partly into the fascia of the mesoglossus (Pl. XXIX. fig. 50). It
exhibits but very little variation, and such as it does consists in the length and breadth
of its insertion tendon and in the single or paired condition of that. In the majority
of Parrots the tendon of each half of the muscle is confluent with its fellow of the
other side ; but in a few (Lorius, Eos, Ara ararauna) it is double. In Lorius domicella
the tendon is narrow but thick, and tends to be cylindrical in form. It appears to be
a muscle that works in conjunction with the mesoglossus, partly in the working of the
“brush” of the tongue in the Lories and Nestor, and partly in depressing the apex of
the tongue in all. The tendon of the muscle moves over the rounded cartilaginous
extremity of the entoglossum.

In Nestor (Pl. XXIX. fig. 46) both the muscle and its tendon are very long, a
condition which is correlated with the great length of the entoglossum. In Séringops
(Pl. XXVIII. fig. 26), as in a few others, it is muscular up to its insertion, but the
fascia is quite tendinous in the middle of its length.

Mytonyoipeus MUuvscLE.

(a) Mylohyoideus anterior.—This muscle consists of two parts—a usually wider, more
superficial anterior (Pl. XXVI. fig. 5, mh.a.) and a deeper posterior portion (mh.a'.).
The two parts arise from a common origin at the antero-dorsal corner of the rami of
the lower jaw (text-fig. 10, p. 248), just behind the line that marks the posterior limit
of the bill (4.). The two halves of each portion unite with each other in the middle
line, in some instances becoming confluent, but in others uniting in a tendinous tract at
their junction. The anterior portion is never, in any way, attached to the hyoid bone,
and simply passes across the inter-ramal area, ventrad of the hyoid; between its median
part and the body of the basihyal there lies a glandular organ of tough consistency
which opens to the buccal cavity by paired lateral ducts, and, in addition to any
glandular function which it may perform, serves to bring the muscle into mechanical
connection with the hyoid. ‘The posterior portion (text-fig. 15, p. 260) is usually
inserted into a bony or cartilaginous nodule (N.) which articulates with the ventral
surface of the urohyal, and to which it is closely bound by a sheath of: connective tissue ;
quite exceptionally it may be inserted into the basihyal just at the origin of the urohyal.

In contrast to the condition existing (4) among the Ratites, Raptores, and Penguins,
the muscle, with one exception, is confined to the anterior third and less of the inter-
ramal area, and in many exhibits evident signs of retrogression. In a few instances
the anterior and posterior parts are about equally strongly developed, but in the
majority the latter is less well developed than the former, and in some has almost
disappeared. The anterior portion in a large number of Parrots exhibits evidence that
it was primitively more extensive in a posterior direction. -In some cases the lower
jaw is backwardly extended, and the two portions of the muscle are then completely

248 MR. G. P. MUDGE ON THE MYOLOGY

hidden; in others the anterior part only is covered, and in yet others neither portion is
covered,

Undoubtedly the most primitive condition of the muscle is that exhibited in
Stringops (Pl. XXVI. fig. 2, mh.a.), where it extends backwards to the posterior
portion of the inter-ramal area. Anteriorly, it arises in the way already indicated,
but posteriorly it arises on either side in the form of a narrow crescentic band of

Text-fig. 10,

Conwrus jendaya.—Ventral view. On the left, half of the mandible has been removed, but otherwise the
parts are in situ. (Twice nat. size.)

Additional letters.

gh.a. = geniohyoideus anterior, s.h. = sternohyoideus.

gh.p. = a posterior.

seh. = serpihyoideus.
ha. = mylohyoideus anterior. st.h. = stylohyoideus,

mha. = 7 oa (posterior portion).

muscular tissue, from the same origin as the serpihyoideus. It has undergone con-

siderable retrogression, for the whole of its middle third consists of nothing but the
persistent fascia of the muscle, and even in the middle line of the anterior third the
muscular fibre has disappeared. The posterior portion (mh.a!.) lies in the same
position that it occupies in other Parrots, but it is inserted to the connective-tissue
sheath that invests the urohyal, a cartilaginous nodule not being present.

OF THE TONGUE OF PARROTS, 249

In Loriculus (Pl. XXIX. fig. 51), Pionopsittacus, Coracopsis, Cyanolyseus, Eclectus,
Nestor, Cacatua roseicapilla, Bolborhynchus, and Peocephalus robustus the anterior
portion of the muscle has undergone still greater retrogression, and is only represented
by a muscular band occupying the anterior fifth or slightly more of the inter-ramal
space; from the posterior border of the muscle (Pl. XXIX. fig. 51, f) a connective-
tissue sheath continuous with its fascia extends backwards to about the posterior end
of the rami.

In Psittacus (Pl. XXVI. fig. 3), Pyrrhura, Psittinus, and Cacatua (Pl. XXVI.
fig. 4) the muscle is similar to that just described, but the persistent fascia (f-) is not
so large, and consists of a tract extending from the muscle for a short distance only,
with a lateral strip running back along the outer border of the stylohyoideus. In
Psittacula and Caica the lateral strips are absent. In Cacatua there is a similar
persistent portion of the fascia (f.p.) to the posterior part of the muscle, which extends
backwards; and in C. leadbeateri there is in addition an anteriorly extended fascia
devoid of muscle-fibre.

In Chrysotis, Tanygnathus, Ptistes, Vini, and Lorius (text-fig. 12, p. 251) the anterior
portion of the muscle is restricted to the anterior fifth or less of the inter-ramal space,
and the persistent fascia is reduced to a pair of lateral strips, which in Chrysotis
ochrocephala are very small. In the remaining Parrots the muscle is restricted to the
anterior third or less of the inter-ramal area, and there is no representative of the
persistent fascia.

In Cacatua (Pl. XXVI. fig. 4), Calopsittacus nove-hollandie, Cyanolyseus, Chrysotis,
Conurus (text-fig. 10), Psittacus (Pl. XXVI. fig. 3), Peocephalus, Pyrrhura, Coracopsis,
Vini, Lorius, and Eos the posterior portion of the muscle is as strongly, or nearly as
strongly, developed as the anterior. In Prioniturus, Psephotus, Platycercus, Calypto-
rhynchus, Cyanorhamphus, Ptistes, Psittacula, Psittinus, Eclectus, Tanygnathus, Pezo-
porus, Pyrrhulopsis, Nasiterna, Loriculus, Bolborhynchus, Pionopsittacus, Paleornis
(text-fig. 11), and Brotogerys (text-fig. 13, p. 252) the posterior portion is smaller than
the anterior; in the last two Parrots it is very small, and in Brotogerys and Caica has
almost undergone complete retrogression, being represented by a few fibres only. In
Microglossus and Nestor the posterior portion is absent, the probable meaning of which
is that it has disappeared.

In Microglossus, Cyanolyseus, Ara (text-fig. 15, p. 260), Caica, Pwocephalus, and
Pyrrhwra both the anterior and posterior portions of the muscle are hidden by the
lower bill; in Hos, Conurus, Psittacula, Tanygnathus, and Nasiterna the anterior
portion alone is completely hidden; in Palwornis (text-fig. 11), Péistes, Platycercus,
Pezoporus, Prioniturus, Psephotus, and Cyanorhamphus the anterior half only of the
anterior portion is thus hidden; and in Cacatua (Pl. XXVI. fig. 4) the anterior third
only. In Brotogerys, Loriculus, Pionopsittacus, Psittacus (Pl. XXVI. fig. 3),

250 MR. G. P. MUDGE ON THE MYOLOGY

Culopsittacus, Eclectus, Chrysotis, Psittinus, Nestor, and Lorius neither portion ig covered
by the mandible. I was able to obtain the tongues only of Pyrrhulopsis and Calypto-
rhynchus, and could not, therefore, examine the particular feature now considered.

In the great majority of Parrots the halves of the posterior portion of the muscle
are inserted one on either side to a bony or cartilaginous nodule (N.) that lies at the
anterior end of the urohyal upon its ventral surface, and to which it is fastened by a

Text-figure 11.

Paleornis torquata.—Ventral view. On the left, one-half of the lower bill has been removed, and the rami of
the mandible slightly pulled outwards to show the origin of the geniohyoideus (gh.a’., gh.a*., and gh.p.).
(Lwice nat. size.)

Additional letters.

gh.a. & a®. = anterior and posterior branches of se.h.p, = serpihyoideus posteri
g ] pin) I or.
anterior division of geniohyoideus. | s.h. = sternohyoideus.
se.h.a. = serpihyoideus anterior. | p.t. = pterygoideus.

sheath of connective tissue. In Chrysotis this nodule is absent, and the muscle is
inserted directly to the sheath investing the urohyal at the root of that. In Conurus
(text-fig. 10) (C. holochlorus excepted) the nodule is elongated and extends to the
posterior extremity of the urohyal, the insertion of the muscle following the extension
of the nodule; Calyptorhynchus is similar in respect of that. In Eclectus it is inserted
to the cartilaginous continuation of the urohyal.

OF THE TONGUE OF PARROTS. 251

In Palwornis (text-fig. 11), Ptistes, Psittacus, Ara, Peocephalus, Calopsittacus,
Pezoporus, Nasiterna, Prioniturus, Platycercus, Psephotus, Cyanorhamphus, and

Text-figure 12.

anehpsay:
Sree

Mo
ee ws:

Fs

mh.a.

ha.
eha.
éhep.

Gabe

et

=

Sara

)))

H pl.

:

LL

i)

es
———=
i)

seh.

nn)
—

cal
nee

=—

SSeS

SSS

saa
tsaa

IS

ee

@
=

SSS

ZZ

om

Lorius domicella.—Ventral view. On the left the serpihyoideus (se.h.a. and se.h.p.) has been removed to show

the ceratohyoideus (c.h.), the sternohyoideus (s.h.), and the geniohyoideus (gh.a. and gh.p.). (Twice
nat. s1ze,)
Additional letters.
c.h. = ceratohyoideus. p.t. = pterygoid muscle.
f. = fascia. t. = tongue.

Lorius domicella (text-fig. 12, p. 251) the posterior portion lies immediately behind

the anterior one, in such a way that the anterior margin of the former is almost in
VOL. XVI,—PArt V. No. 6.—October, 1902. 20

202 MR. G. P. MUDGE ON THE MYOLOGY

contact with the posterior margin of the latter. In Kclectus, Pyrrhura, Psittinus, and
Lorius flavo-palliatus (text-fig. 14, p. 256) the interval is a little greater. In Los,
Chrysotis, Conurus (text-fig. 10, p. 248), Cyanolyseus, and Brotogerys (text-fig. 13,
p. 252) the interval is very great, except of course at the common origin of the two
portions.

The general conclusion arising from the foregoing facts is that both the anterior and
posterior portions of the muscle are undergoing retrogression. Stringops stands alone

Text-figure 13.

=
Ty
nt
a
,*

CES

Brotogerys pyrrhopterus.—Ventral view. On the left the serpihyoideus has been partially cut away.
(Twice nat. size.)
Additional letter.

N. = cartilaginous nodule.

in that its muscle exhibits the most primitive condition, all the others in respect of
this muscle having attained a fairly advanced progression, some slightly more than
others. ‘There is no definite comparison possible in any given individual between
the stage of specialization reached by this muscle and that attained by either the
ceratoglossus or thyroglossus muscle.

The more or less extensive connective-tissue sheet, or strip, that extends backwards
from the muscle in some Parrots is shown to be a persistent fascia in virtue of the facts
that it is continuous with the ventral and dorsal fascie of the muscle, and that, in

9

OF THE TONGUE OF PARROTS. 253

Chrysotis wstiva, there are pigmented blood-capillaries, which, when microscopically
examined, show the characteristic meshwork of muscular blood-capillaries; moreover,
the condition of the muscle in Stringops is such as to leave no room for doubt as to
the nature of this tissue.

The retrogression of the posterior portion of the muscle can be traced, step by step,
up to its complete disappearance in Nestor and Microglossus. It is strange that such
a generalized tongue as that of the latter Parrot should have reached, in respect of
this, the most advanced stage.

(8) Mylohyoideus posterior —This muscle is composed of two portions—an inner,
more posterior serpihyoideus (se.h.p.), and an outer, more anterior stylohyoideus (se.h.a.).
In all Parrots, except the Loriide, both portions are present, but in them the stylo-
hyoideus is absent; it will be shown that the Loriidean condition is specialized.

The serpihyoideus and stylohyoideus arise from a common origin at the posterior
extremity of the mandible, and passing forwards as a single muscle for a greater or less
distance they separate, and the former becomes inserted partly into the nodule lying
on the ventral surface of the urohyal, or, in the absence of the nodule, into the sheath
investing the urohyal, and partly into the uro-hypobranchial tendon, which is attached
at one end to the urohyal nodule (N.) and at the other to the head of the hypobranchial ;
the stylohyoideus turns outwards, passes round the lateral ceratoglossal, parallel with
and in front of the sternohyoideus, and reaches its insertion into the outer lateral
surface of the parahyal process.

In Cacatua (Pl. XXVI. fig. 4, se.h.), Conurus jendaya, C. cactorum, Psittacula, Cyano-
lyseus, Ptistes, Coracopsis, Bolborhynchus, Loriculus, and Brotogerys (text-fig. 13) the
serpihyoideus is a single undivided muscle. In Cacatua galerita (Pl. XXVIII. fig. 25)
the muscle sends a small tongue-like projection on to the ventral surface of the uro-
hypobranchial tendon, which nearly meets the origin of the ceratoglossus inferior anticus
accessorius, and another along the outer extremity of the tendon; in C. roseicapilla
this inner tongue-like projection is much wider. In Pionopsittacus the muscle exhibits
a remarkable contraction of its substance at its origin, which is tendinous, and fore-
shadows the condition of that in Hos and Pezoporus.

In Conurus holochlorus, Eclectus, Paleornis (Pl. XXVIII. fig. 32), and Pyrrhura
(Pl. XXIX. fig. 40) the serpihyoideus shows a very incipient division of the muscle
into an outer and inner portion, in the form of a slight, almost imperceptible thinning
of the muscle-fibres in the middie line at the anterior end of the muscle, In
Palwornis there is in addition a very slight plane of division continued backwards
from the thinned area, and more marked in the right than the left muscle.

In Chrysotis (Pl. XXVIII. fig. 28), Cacatua sulphurea, Calopsittacus, dra ararauna
(Pl. XXVIII. fig. 24), Psittacus (Pl. XXVI. fig. 3), Nasiterna, Caica, Calyptorhynchus
funereus, and Tanygnathus the thinned area of retrogression is more marked and

20 2

254 MR. G. P. MUDGE ON THE MYOLOGY

muscle-fibres have disappeared from it, leaving only the fascia behind. In Cacatua
sulphurea the retrogression in the right-hand muscle is more pronounced than in
the left. In Psittinus, Lorius domicella (text-fig. 12), Cyanorhamphus, Prioniturus,
Platycercus (Pl. XXVI. fig. 5), and Calyptorhynchus banksi the area of retrogression
has extended posteriorly and become a definite plane of division, which divides the
muscle into two distinct parts along the length of its anterior two-thirds or more. In
Lorius flavo-palliatus (text-fig. 14) the separation is very distinct, but does not extend
beyond the anterior fifth. In Stringops the division only extends to the anterior half.
In Pezoporus (P]. X XIX. fig. 47) the muscle is divided into two parts along its whole
length, and the origin of the inner of the two parts exhibits a remarkable contraction
similar to that in Kos (Pl. XXVI. fig. 1), but it possesses no tendon or tendinous
thickening of the fascia. In Pwocephalus riippelli the plane of division does not quite
reach to the posterior extremity of the muscle, but the inner portion exhibits at its
origin the peculiar contraction of its substance above mentioned, and in addition it has
developed a weak and small tendon; the division of the muscle is not quite so complete
on the left as on the right side. In Pwocephalus robustus the right-hand muscle is not
divided to a greater extent than the left-hand one in P. riippelli, and the left-hand
one not at all; otherwise it is as that in P. riippelli. In Eos (Pl. XXVI. fig. 1) this
condition reaches its maximum development; the muscle is very strongly developed,
and divided along its whole length into two portions, of which the inner overlaps the
outer one posteriorly, and at its contracted origin has developed a well-marked tendon
which extends forwards along the outer margin of the posterior half of the muscle.
In Nestor (Pl. XXIX. fig. 46, se.h.) there appears to be only a single portion present,
and this probably represents only the inner portion, since its insertion corresponds to
that; that part of the uro-hypobranchial tendon which represents the insertion of the
outer part in other Parrots is free and gives no insertion to any muscle. In Nestor
therefore the outer part has probably quite retrogressed. In Lorius (Pl. XXIX.
figs. 37 & 38), Hos, and Vini the uro-hypobranchial tendon (w.ten.) has the same
relations as that in other Parrots, and the outer portion of the serpihyoideus is
inserted to it as in them; but in addition the antero-outer corner of the muscle
is prolonged forwards and forms an independent insertion (éns.), slightly tendinous,
on the basihyal between the lateral and anterior portion of the inferior ceratoglossals.

In Cacatua (Pl. XXVIII. fig. 25), Psittacus (Pl. XXVI. fig. 3), Stringops, Eclectus,
Calyptorhynchus, Ptistes, and Conurus cactorum the stylohyoideus is confluent with
the serpihyoideus along the length of its posterior half. In Chrysotis (Pl. XX VII.
fig. 28), Coracopsis (Pl. XXVIII. fig. 31), Conurus jendaya, C. holochlorus, Psittinus,
Bolborhynchus, Pyrrhura, Pezoporus (Pl. XXIX. fig. 47), Psittacula, Peocephalus,
Paleornis, Platycercus, Nasiterna, Loriculus, Brotogerys, Psephotus, and Catca the
two muscles are confluent only at their origin, or for a very little way in front of that.

OF THE TONGUE OF PARROTS. 255

In Ara (Pl. XXVIII. figs. 24 & 27), Nestor (Pl. XXIX. fig. 46), and Pionopsittacus
the two muscles are not confluent at any portion of their course, though they arise side
by side from the posterior extremity of the mandible. In Ara ararauna the stylo-
hyoideus crosses the ventral surface of the serpihyoideus just after its origin.

In Paleornis, Eclectus (Pl. XXIX. fig. 49), Bolborhynchus, Psephotus, Ara ararauna
(PL XXVIII. fig. 24), Conurus jendaya, Cacatua, and Chrysotis the stylohyoideus
exhibits a slight retrogression of its muscle-fibres at its origin, the fascia remaining.
In Ara macao (Pl. XXVIII. fig. 27), Conurus cactorum, Pezoporus (Pl. XXIX.
fig. 47), Pwocephalus, Pionopsittacus, and Stringops (P1. XXVIII. fig. 26) the retro-
gression is more considerable, and in Stringops and Pezoporus it practically involves
the whole origin and a considerable portion anteriorly to that. In Pezoporus the
whole of the left-hand muscle has retrogressed and not a trace of it can be found,
while, as already indicated, the origin of the right-hand one has practically disappeared ;
the insertion has also retrogressed, for it is represented (Pl. XXVI. fig. 8) by a mere
filament of connective tissue, and the muscle can be, therefore, of no functional value.
In Nymphicus the insertion is also reduced to the condition of a mere filament. In
Platycercus (Pl. XXVI. figs. 5 & 11) also the muscle is very thin and suggestive of
an early disappearance. In Pionopsittacus (Pl. XXIX. fig. 43) there is the same
advanced retrogression, for its origin is gone and its insertion nearly so.

In Lorius (text-figs. 12, 14), Vini, and Eos (Pl. XXVI. fig. 1) the condition fore-
shadowed in Pezoporus has been attained, for the stylohyoideus is absent on both
sides. In all three there is a vacancy on the parahyal arch (Pl. XXVII. fig. 21,
P.A.) lying between the origin of the thyrohyoideus (th.h.) and the insertion of the
serpihyoideus (s./.), which corresponds in position with the insertion of the muscle in
those Parrots in which it is present; and in Zorius there is attached at this part a
sheet of connective tissue, ribbon-like in form and of but short extent, which probably
represents the last remains of the fascia of the muscle.

In Nestor (Pls. XX VII. & XXIX. figs. 22 & 46, st.h.) the muscle is very thin and
its insertion is unlike that in any other Parrot, and in respect of which it stands
alone; it is inserted to the hypocleidium of the completed parahyal arch, immediately
anterior to the insertion of the sternohyoideus.

In the majority of Parrots the stylohyoideus is inserted at the apical portion of the
parahyal processes; but in Pyrrhulopsis, Loriculus, Pezoporus, Cyanorhamphus, and
Tanygnathus it is inserted behind the apex, so that the free extremities of the para-
hyal processes extend some little way beyond the anterior margin of the insertion of
the muscle. And in Cyanorhamphus and Pyrrhulopsis the free portions of the processes
curve inwards towards the middle line, and in the former Parrot almost meet each
other; it strongly suggests a growing forwards of the parahyal processes in order to
form the completed parahyal arch of the Loriide and Nestor.

256 MR. G. P. MUDGE ON THE MYOLOGY

In Prioniturus (text-fig. 16, p. 260) the stylohyoideus (st.h.) is tendinous at its
insertion, and it is inserted in common with a branch of the sternohyoideus, with
which it becomes confluent just before its insertion. In Stringops (Pl. XXVII.
fig. 18) the stylohyoideus divides into two some distance before reaching its insertion ;
the posterior branch is inserted at the usual position on the parahyal process, while the
anterior one passes towards the middle line and becomes confluent with the internal

twig (th.g.1) of the thyroglossus.

Text-figure 14,

Lorius flavo-palliatus.—-Ventral view. On the left the serpihyoideus has been removed, to show the cerato-
hyoideus (¢.z.) and sternohyoideus (s.h.) and the course of the geniohyoideus (yh.a. and gh.p.). Other
letters as before. (Twice nat. size.)

In Prioniturus, Chrysotis, Bolborhynchus, and Calopsitéacus the uro-hypobranchial
tendon arises directly from the sheath investing the urohyal, as the nodule (N.) that
articulates with the ventral surface of that in other Parrots is absent.

A general review of the facts concerning this muscle (posterior mylohyoideus)
indicates that its two constituent portions have arisen from a common muscle, since in
some Parrots the stylo- and serpihyoideus are confluent along the greater portion of
their course, and a gradual separation of the two can be traced. The stylohyoideus

OF THE TONGUE OF PARROTS. 257

appears to be undergoing retrogression, for in many Parrots its origin is represented by
fascia alone, while in others its insertion is reduced to a functionless filament ; in
Pezoporus the muscle of one side of the tongue has disappeared and that of the other is
going; and in yet a few others there is a general thinning of the muscle. In Lorius,
Eos, and Vini (the only three members of the Loriide obtainable) the muscle has com-
pletely disappeared, the position of its insertion being indicated in one of them by
connective tissue (vestigial fascia) and in the others by a space upon the parahyal
process.

In all Parrots, except the Loriide, the outer portion of the serpihyoideus is inserted
to the uro-hypobranchial tendon, and does not extend beyond it, while in the Loriide
it is prolonged forwards to an independent insertion at the postero-outer angle of the
basihyal. Thus the Loriide are characterized by this extended insertion and by the
absence of the stylohyoideus muscle.

Nestor occupies a position of isolation with respect to its hypocleidal insertion of the
stylohyoideus.

There are indications, in the projection forwards of the parahyal processes beyond the
insertion of the stylohyoideus, in certain Parrots of an approach to the Loriidean
condition of a completed parahyal arch.

There are all stages in the division of the serpihyoideus into two parts, from an
incipient thinning, localized anteriorly and barely perceptible, to a well-defined plane
of division passing the whole length of the muscle. In all Parrots but one, the two
portions of the muscle persist; but in Nestor it is probable that the outer one has
disappeared. In certain Parrots the inner portion exhibits a remarkable contraction of
its substance at its origin, which in some is not tendinous, but in others markedly so;
Fos represents the highest specialization in this direction.

Thus the muscle appears to be specializing in two directions: in one, by the
complete retrogression of the stylohyoideus, by the division of the serpihyoideus and
by the shifting forwards of part of its origin to the basihyal; and in the other direction
additionally by the contraction of, and the subsequent formation of, a tendon at the
origin of the inner portion.

As far as the characters of the tongue are concerned, we may say that within the
Loriide—the most specialized family of Parrots—two lines of evolution seem to be
mapping themselves: the one exemplified by Loriws and Vini, and characterized by an
uncontracted origin of the serpihyoideus and by the tendon of the ceratoglossus
inferior posticus not being fan-shaped at its origin from the muscle; and the other by
Kos, characterized by the contracted origin of the inner portion of the serpihyoideus
and the fan-shaped ceratoglossal tendon. Conditions foreshadowing both these
characters of Hos are met with in certain of the less specialized Parrots.

2)

MR. G. P. MUDGE ON THE MYOLOGY

bo
Cr
=

STERNOHYOIDEUS.

This muscle arises from the anterior end of the ventral border of the sternal carina,
and passing forwards along the ventro-Jateral aspect of the trachea, on either side, it
passes between the ceratohyoideus and posterior mylohyoideus, whence it reaches the
dorsal surface of the hyoid and its insertion into the posterior portion of the outer
margin of the parahyal processes. In some instances the insertion extends backwards
along the body of the basihyal and may even reach to some distance along the hypo-
branchial. In but very few Parrots (Hos, Ptistes, Psittacus, Pezoporus, Stringops, and
Aprosmictus only) is it a continuous muscle from its origin to its insertion; in the
majority, the middle portion of that part which extends along the neck is either
exceedingly attenuated—represented by a few scattered fibres on the skin—or is quite
retrogressed ; even in Hos and Aprosmictus the greater portion of it is attached to the
skin of the neck. In a few its origin has retrogressed, and in others distinct evidences
of retrogression may be seen at one part or another of its course.

In Coracopsis, Microglossus, Cacatua roseicapilla, C. sulphurea, C. alba, C. triton,
and Kclectus (text-fig. 7, p. 251) the insertion of the muscle is upon the parahyal
process with an extension backwards to the inner surface of the hypobranchial. The
muscle divides just before reaching its insertion, the anterior branch becoming inserted
to the dorso-lateral surface of the parahyal process and the posterior to the inner
surface of the hypobranchial. In Cacatwa triton the extension is along a little more
than the anterior third of the hypobranchial, and is greater than in any other Parrot ;
in ©. roseicapilla and C. alba the two branches are connected by an intermediate piece
of connective tissue, and the posterior branch (that inserted on the hypobranchial)
shows signs of retrogression; in C, su/phurea the hypobranchial insertion is only
represented by a few muscular fibres, it having undergone a great amount of retro-
gression. In Microglossus the hypobranchial insertion is between the ceratoglossus
superior and the hypoglossus obliquus, instead of to the inner side of the former muscle.
In Kclectus (text-fig. 7, p. 231) the parahyal insertion is very broad and extends
along the whole length of the parahyal process, while the hypobranchial portion
exhibits signs of retrogression as it turns round the ceratoglossus lateralis. In
all other Parrots the hypobranchial insertion has disappeared. In Pyrrhulopsis the
insertion of the muscle into the parahyal process extends backwards along the dorsal
surface of the body of the basihyal to the posterior extremity of that. In all other
Parrots, Lorius (Pl. XXVIL. fig. 21, s..) and Hos excepted, the insertion of the muscle
is restricted to the parahyal process, and usually to its posterior half; sometimes it is
inserted into the lateral surface, and more rarely into the dorsal surface. In Chrysotis
vuvidigena, Eclectus, and Cacatua galerita the insertion extends up to the anterior
extremity of the parahyal process. In Lorius domicella (Pl. XXVII. fig. 21) and
L. flavo-palliatus the muscle is inserted to the posterior two-thirds of the parahyal

OF THE TONGUE OF PARROTS. 259

arch and the dorsal surface of the body of the basihyal; in £os its insertion is limited
to the basihyal, and in Vini to the posterior half of the parahyal arch. In Westor it is
inserted to the parahyal arch just behind the hypocleidium, and is thus more anterior
than in the Lories.

In Ara macao (Pl. XXVIT. fig. 20, s.h.) the muscle just before reaching its insertion
divides into a larger and a smaller branch, of which the former becomes inserted into
the parahyal process and the latter, in common with the hypoglossus obliquus and
thyroglossus, into the posterior extremity of the os entoglossum. In Calyptorhynchus
funereus the muscle just at its insertion becomes confluent with the thyroglossus. In
Pezoporus (Pl. XX VI. fig. 8, s.4.) the muscle narrows and becomes inserted by a small
tendon. In Prioniturus (text-fig. 16) the muscle divides into two branches, the anterior
of which becomes confluent with the stylohyoideus and is inserted with it in a common
and tendinous insertion near the apex of the parahyal process, while the latter becomes
inserted by a tendinous insertion to the root of that.

In Brotogerys the muscle has retrogressed at the point where it turns round the
ceratoglossus lateralis, only the fascia persisting.

In Ara ararauna (text-fig. 15), Platycercus, Loriculus, Calopsittacus, and Cacatua
galerita the origin of the muscle at the carini sterni has undergone complete retro-
gression, and in the first- and last-named Parrot it is represented by a narrow tract of
fat. In Bolborhynchus, Psittacula, Nasiterna, and Tanygnathus the origin is repre-
sented by a mere trace of muscular tissue; while in Conurus holochlorus, Eclectus,
Chrysotis westiva, C. viridigena, C. ochrocephala, Peocephalus, and Conurus jendaya it is
somewhat stouter, but still very narrow. In Paleornis and the remaining Parrots
it is well defined; and in Nestor it is very strongly developed. In Stringops, in
correlation with the absence of a carini sterni, the muscle arises from the skin of the
thorax in this region by three strands which soon unite to form a single trunk.

In Kos, Ptistes, Aprosmictus, Pezoporus, Psittacus, and Stringops the muscle is
continuous from its origin to insertion. In Stringops it remains free of the skin
throughout its course, but in all other Parrots it is attached to that along the greater
portion of its course. In the six Parrots just mentioned it widens and thins in its
mid-cervical region, except in Kos, in which it thickens as well as widens. In Lorius
domicella, L. flavo-patliatus, Chrysotis ochrocephala, and Nestor it becomes exceedingly
attenuated in the mid-cervical region, In all the remaining Parrots the muscle has
undergone retrogression in this region, usually disappearing about half an inch to an
inch from its origin, and reappearing a little posterior to the hinder edge of the
serpihyoideus,

Primitively, the muscle thus appears to have been a continuous one from its origin
to insertion, but it has undergone more or less extensive retrogression, principally in
the mid-cervical region, but also at its origin and insertion. Its insertion appears to

VOL. XVI.—ParT V. No. 7.—October, 1902. 2P

260 MR. G, P. MUDGE ON THE MYOLOGY

Text-fig. 15.

Ara ararauna,—Ventral view. On the right, half the lower bill has been removed and the stylo-
hyoideus (st.h.) reflected to show the course of the geniohyoideus (gh.a ). (Nat. size.)

Text-fig. 16.

%

ree I
Cee
Se ara

Prioniturus.—Dorsal view, to show the connection between the sternohyoideus (s.h.) and the stylo-
hyoideus (st...) near their insertions to the parahyal process (P.P.). (Much enlarged.)

OF THE TONGUE OF PARROTS. 261

have been of a much more extensive nature primitively, but it has retrogressed in the
majority of Parrots along its hypobranchial and basihyal portions, leaving only its
parahyal process part.

GENIOHYOIDEUS.

In Parrots this muscle has reached a stage not known to have been attained in other
birds. In Chauna, Rhytidoceros, Cygnus, Pelecanus, Lophophorus, Palamedea, Corvus,
Anser, Procellaria, and Spheniscus this muscle is known to be single. In Nectarinia,
Otis, Rhea, Struthio, Dromeus, Rhynchotus, Ciconia, and Opisthocomus it is double
(8 & 9). In some Parrots the muscle consists of two divisions, but in the majority
it is composed of three, which have arisen from the primitive set of two, by the
splitting longitudinally of the anterior one of these.

The most posterior division of the muscle arises from either the ventral margin of
the rami of the mandible (text-fig. 10, gh.p), usually about one-third of the way behind
the hinder margin of the lower bill, or from the outer surface of the latter (text-
fig. 12, p. 251). The two portions of the anterior division arise from a common origin
at the inner surface of the antero-dorsal portion of the lower jaw (text-fig. 11, gh.al.,
gh.a?.), just posterior to and slightly ventrad of the origin of the mylohyoideus anterior ;
they are usually bound together by connective tissue. The posterior portion is
inserted into the dorsal surface of the ceratobranchial (Pl. XXVII. tig. 12, gh.p.);
the anterior division of the anterior muscle (gh.a!.) into the posterior extremity of
the hypobranchial, folding round its dorsal and ventral surfaces, and the posterior
division (gh.a?.) into the ventral surface of the ceratobranchial.

In Lorius (text-fig. 12, p. 251, and Pl. XXVII. fig. 21), Hos, Vini, Prioniturus,
Chrysotis cestiva, C. ochrocephala, Poocephalus riippelli, Ptistes, Ara ararauna
(Pl. XXVIII. fig. 24), Pstttacus, Cyanorhamphus, Psephotus, Nasiterna, Eclectus,
Loriculus, Paleornis, Caica, Platycercus, and Lanygnathus the muscle consists of
three divisions, the anterior two of which are usually closely bound together with
connective tissue at their common origin. In Prioniturus, Psephotus, Eclectus, and
Tanygnathus the outer one of the two anterior portions has developed a small tendon
at its origin.

In Stringops and Lrotogerys the anterior muscle is divided into two along the
greater portion of its length, but at its origin and for some distance behind it is a
single muscle. In Pezoporus, Peocephalus robustus, Pionopsittacus, Psittacula, and
Cyanolyseus the anterior muscle is more or less divided into two in a longitudinal
direction.

In Chrysotis panamensis, Cacatua sulphurea, C. roseicapilla, C. leadbeateri, C. galerita,
Calopsittacus, Psittinus, Ara macao, Conurus jendaya, Bolborhynchus, and Calypto-
rhynchus the muscle is primitive and consists of only two divisions, a single anterior

2EP2

262 MR. G. P. MUDGE ON THE MYOLOGY

and a posterior one. In Conurus jendaya and Cacatua galerita the anterior portion
is very indistinctly divided into two.

In Lorius domicella (text-fig. 12), Vini, Prioniturus, Chrysotis, Ptistes, Nasiterna,
Bolborhynchus, Loriculus, Pyrrhura, Brotogerys (text-tig. 13), Palwornis, Platycercus,
and Tanygnathus the posterior division of the muscle arises from the ventral margin
of the rami of the mandible. In Lorius flavo-palliatus (text-fig. 14), Conwrus jendaya
(text-fig. 10), Hos, Stringops, Pezoporus, Pwocephalus, Ara, Psittacus (Pl. XXVI.
fig. 3), Psittacula, Eclectus, Cyanolyseus, Coracopsis, and Cacatua it arises from the
outer surface of the rami.

In Nestor notabilis the muscle consists of two divisions only, but they become
confluent at their insertion (Pl. XXIX. fig. 46), and form a tubular investment round
the extremity of the hypobranchial and the whole length of the ceratobranchial.

THE GeEnroGLossus MUSCLE.

This is a paired muscle arising from the inner surface of the posterior end of the
lower bill, immediately on either side of the middle line. Each half passes upwards
and forwards, and becomes inserted (Pl. X XIX. fig. 50, gg.) into a thin ridge which marks
the dorsal limit of the posterior lateral process of the entoglossum (ef. P. Z. S. 1894,
p- 166). It has fundamentally the same arrangement in all Parrots, except Nestor, in
which the two portions of the muscle pass dorsally to the entoglossum and become
confluent with each other in the middle line, so that there is no insertion to the ento-
glossum; the muscle merely forms a loop round it.

THE CERATOHYOIDEUS MUSCLE.

This muscle exhibits but little variation. Its origin in some instances (Pl. XXVIII.
fig. 28) is entirely from the sheath investing the urohyal; in others it is partly from
that and partly from the posterior border of the uro-hypobranchial tendon; and ina
few (Pl. XXVIII. fig. 24) it is partly from the nodule (N.) on the ventral surface of the
urohyal and partly from the uro-hypobranchial tendon (u.ten.). Its insertion in all
cases is into the inner surface of the hypobranchial, ventrad of the origin of the
ceratoglossus inferior posticus, sometimes towards its anterior and at others towards
its posterior end.

In Microglossus, Tanygnathus, Pyrrhulopsis, Platycercus, Peocephalus riippelli,
Cacatua, Nestor, Psittacus, Psephotus, Conurus holochlorus, Coracopsis, and Brotogerys
(Pl. XXVIII. fig. 53, ch.) it arises entirely from the urohyal sheath. In Calyptorhynchus,
Paleornis, Loriculus, Eclectus, Bolborhynchus, Psittacula, Nasiterna, Cyanorhamphus,
Pyrrhura, Pionopsittacus, Ptistes, Psittinus, Conurus jendaya, C. cactorum, Pezoporus,
Cyanolyseus, Stringops, Calopsittacus, and Prioniturus it arises partly from the urohyal

OF THE TONGUE OF PARROTS. 263

sheath and partly from the uro-hypobranchial tendon; in Cyanorhamphus and Stringops
it arises mainly from the uro-hypobranchial tendon, and in Calyptorhynchus chiefly
from the urohyal sheath. In Chrysotis (Pl. XXVIII. fig. 28), Caica, and Deroptyus
it arises in main part from the anterior two-thirds of the urohyal, and to a small extent
from the posterior border of the basihyal. In Ara, Peocephalus robustus, Lorius
(Pl. XXIX. fig. 37, ch.), Eos (Pl. XXIX. fig. 39), and Vind it arises in part from the
nodule on the ventral surface of the urohyal, and in part from the uro-hypobranchial
tendon.

In Pezoporus and Pyrrhulopsis there is developed along the inner side at the anterior
end of the muscle a small tendinous tract, which extends about half its length.

In Eelectus, Ara, Cacatua triton, and C. alba the muscle is inserted along the
anterior half of the hypobranchial. In Microglossus, Prioniturus, Cacatua galerita,
C. leadbeateri, and C. roseicapilla it is inserted into the anterior two-thirds; and in
Pyrrhulopsis, Nestor, and Calyptorhynchus into the posterior two-thirds. In Lorius
(Pl. X XIX. fig. 37), Hos, Vini, Brotogerys (Pl. XXVIII. fig. 33), Loriculus, Conurus
holochlorus, Nasiterna, Psittacus, Ptistes, Psittinus, Peocephalus, Pezoporus, Stringops,
Calopsittacus, Deroptyus, and Chrysotis it is inserted along nearly the whole length
of the bone.

Tue Mesoaiossus Muvscue.

This muscle has not been previously described. It is triangular in form, with its
apex directed backwards, and connected with the superior ceratoglossals in a manner
already described (ante, p. 227). It lies in the dorsal concavity of the entoglossum
(Pl. XXVI. fig. 11, mg., and Pl. XXIX. fig. 50, mg.), and is attached on the one hand to
the superior ceratoglossais, and on the other to the hypoglossus rectus and the membrane
of the extremity of the tongue. In comparatively very few Parrots it is wholly
muscular in nature; in the greater number it is composed of muscle-fibres and a
dense connective tissue, in varying proportions, inextricably mixed together; in yet
a large number still it is wholly composed of connective tissue of a very dense and
resistant nature; and in one or two it is represented by a connective-tissue membrane
only. ‘The muscle, or that which represents it, is invested by a thick fascia.

In Nestor (Pl. XX VIL. fig. 22, mg!.) and Calyptorhynchus the muscle is not represented,
except by a thick membranous sheet of white fibrous tissue. In Platycercus, Cacatwa
(Pl. XXVILI. fig. 15, mg!.), Conurus, Calopsittacus, Psittinus, Stringops (Pl. XXVII.
fig. 18), Pyrrhura (Pl. XXVII. fig. 19), Psittacula, Bolborhynchus, Cyanolyseus, and
Brotogerys it is represented by a mass of dense, white, fibrous tissue, invested in a
tough sheath; in the tissue of Cacatua triton branched pigment-cells are present. In
Microglossus, Pyrrhulopsis, Eclectus (text-fig. 7, p. 231), Palwornis, and Tanygnathus
muscles-fibres have appeared in the mass of fibrous tissue ; in Chrysotis (Pl. XX VIL.

264 MR. G. P. MUDGE ON THE MYOLOGY

fig. 14, mg.), Pezoporus (P]. XX VI. fig. 8, mg.), Nastterna, Deroptyus, and Loriculus the
muscle-fibres are slightly more abundant, and about equal in quantity to the fibrous
tissue ; and in Prioniturus, Pwocephalus (Pl. XXVI. fig. 10), Pionopsittacus, and Caica
the muscle-fibres predominate. In Microglossus I found in the substance of the muscle
some oval sacs containing an axillary strand and some very small cells with processes ;
they are probably sensory in nature and deserve investigation by modern methods. In
Ptistes, Ara (P|. XXVII. fig. 20), Psittacus, Coracopsis, Cyanorhamphus, and Psephotus
the muscular element constitutes nearly the whole of the muscle, though the amount of
connective tissue present is greater than one would expect to find usually. In Lorius
(Pl. XXVIL. fig. 21), Hos, and Vint the muscle is well developed and of a normal
nature.

Trans. Zoot. Soc., Vou. XVI.] [To face p. 264.

LORIIDA.

NESTORIDA.

\

THE CLASSIFICATION OF PARROTS ACCORDING TO THEIR LINGUAL MYOLOGY
AND OSTEOLOGY.

(A.) Parahyal arch complete. Stylohyoideus absent. Outer portion of serpihyoideus inserted to basihyal. Cerato-
glossus inferior posticus extends back to posterior end of hypobranchial. A ceratoglossus inferior anticus
accessorius absent.

(1) The tendon of the ceratoglossus inferior spreads out in a fan-shaped manner over the posterior portion

—

of the muscle. Inner division of serpihyoideus contracted at origin,
Fos.

(2) The tendon of inferior ceratoglossus is merely continued back on to the ceratoglossus inferior posticus,

Kosina
—

a without widening. Serpihyoideus is not contracted at origin.
ie

a Lorius.

& . .

4 Vini.

(B.) Parahyal areh complete. Stylohyoideus narrow, inserted to hypocleidium of parahyal arch, and not confluent
with serpihyoideus at any part of its course. Outer (anterior) portion of serpihyoideus not represented.
Ceratoglossus inferior posticus does not extend back to posterior end of hypobranchial. The posterior
division of anterior mylohyoideus absent.

Nestor.

(C.) Parahyal arch incomplete. Stylohyoideus usually well developed, and inserted to or near apical pertion
of parahval process. Outer portion of serpihvoideus inserted to head of hvpobranchial. The ceratoclossns

Tce

Trans, Zoor. Soc., Vor, XVI.)
(Zo Face p, 264.

THE CLASSIFICATION OF PARROTS ACCORDING TO THEIR LINGUAL MYOLOGY
AND OSTEOLOGY.

(A.) Parahyal arch complete. Stylohyoideus absent.

glossus inferior posticus extends back to pos!
accessorius absent,

Outer portion of serpihyoideus inserted to basihyal. Cerato-
terior ond of hypobranchial. A ceratoglossus inferior anticus

A {@ The tendon of the ceratoglossus inferior spreads out in a fan-shaped manner over the posterior portion
of the muscle, Inner division of serpihyoideus contracted at origin,
Eos.
(2) The tendon of inferior ceratoglossus is merely continued back on to the ceratoglossus inferior posticus,
Without widening. Serpihyoideus is not contracted at origin,
Lorius,
\ Vini.

Eosw.

LORIIDE.

Lorun2.

+) Parahyal arch complete. Stylohyoideus narrow, inserted to hypocleidium of parabyal arch, aud not confluent
| with serpihyoideus at any part of its course. Outer (anterior) portion of serpihyoideus not represented,

Ceratoglossus inferior postions does not oxtend back to posterior end of hypobranchial. The posterior
| division of anterior mylohyoideus absent.
Nestor.

NESTORIDE,

(C.) Parahyal arch incomplete. Stylohyoideus usually well developed, and inserted to or near apical portion
of parahyal process, Outer portion of serpihyoideus inserted to head of hypobranchial, The ceratoglossus
inferior posticus may or may not extend back to the posterior end of the hypobranchial, and exceptionally
may be absent. A ceratoglossus inferior anticus accessorius, with but one exception, present.

a

- The ventral fascia of the ceratoglossus inferior anticus is not tendinous: the ceratoglossus inferior posticus
extends back to the posterior end of the hypobranchial =3

(a) The thyroglossus arises from the parahyal process.
(«) The inner portion of the cerateglossus inferior anticus has reached stage LIL of retrogression.
Psittacula. 2
Cyanorhamphus.

Nymphicus,

Psrrracunin&.

(4) The inner portion of the ceratoglossus inferior auticus has reached stage IL of retrogression,
Pyrrkulopsis.
| | . Cnica, s
(A) The thyroglossus arises from the entoglossum.
(a) The inner portion of the ceratoglossus inferior anticus has reached stage ILI of retrogression.

Loriculus. r,
Pyrchura. ,

(4) The inner portion of the ceratoglossus inferior auticus has reached stage IL of retrogression.

Pyrrovrine.

I. The ventral fascia of the ceratoglossus inferior anticus is tendinous,
(2) The tendon of the ceratoglossus inferior is well developed, and the ceratoglossus inferior posticus
extends back to the posterior end of the hypobranchial = }.

(a) The thyroglossus arises from the parahyal process.
Pezoporus.

Platycercus. rho
Bolborhiynchus. 2

Prioniturus.

PSITTACIDA.

(8) The thyroglossus arises from the entoglossum.
: Pococephalus. 3{
| Tanygnathis.
| < Ptistes.
2 . 13
& Pionopsittacus.
4 ah
| Psittinus.

|
| | (3) ‘Pho tendon of the ceratoglossus inferior is not well developed. —
~ (q) The coratoglossus inferior postious extends back to the posterior end of the hypobranchiul = $.
Poephotus. sel

170

Conurus.

Palerornis

Coxvrine.

| \ Brotogerys? 2 ;
) (8) The ceratoglossus inferior postious extends back along the anterior two-thirds only of the
( & hypobranchial =§.
Deroptyus.
gS Psittacus.
oglossus inferior posticus extends back along the anterior half only of the hypo-

Group II.

(y) The cerati
branchial = 4.
Exlectus.

Coracapsis.

(3) The tendon of the ceratoglossus inferior posticus is not developed, and a thickened tract in the

tendinous faseia foreshadowing its formation may or may not be present.

(a) The thyrohyoideus accessorius is absent.
Cyanolyscus. 2os
Chrysotis. 2bs
)

slra.

Conysotrn%,

Cacatua. ts
Stringops. SF
Microglossus~
Calopsittacus.

FS
5
E
=
2
tS)

Nasiterna.
Calyptorhynchus. 16

wn oe
hehe

OF THE TONGUE OF PARROTS. 265

TABULATION OF THE CHARACTERS OF THE MORE IMPORTANT MUSCLES, AND THE ARRANGE-
MENT OF THE GENERA DESCRIBED, INTO STAGES ACCORDING TO THE DEGREE OF
DEVELOPMENT OF THE TENDON OF THE CERATOGLOSSUS INFERIOR.

PA = Parahyal arch,
PP’ = Parahyal process origin (primitive condition).

PP = Parahyal process origin (secondary condition).
OK = Entoglossum.

HB = Hypobranchial.

OL = The thyroglossus has lost its origin and lies free in the entoglossal concavity or is attached to
the membrane of the tongue.

OL & PP’ = The thyroglossus has split and its origin is partly from parahyal process (primitive condition)

and partly it is as in OL. :
— = Absent.
P = Present.
D = Divided.

U = Single or undivided.
E.S, = Fairly strongly developed.
T.F. = Tendinous fascia.
W.T.F. = Weak tendinous fascia.
T.T. = Tendinous tract.
S. = Strongly developed.
V.S. = Very strongly developed.
B. = Broad.
Absent = Tendon or tendinous fascia absent.
CG.1.A!. = Inner portion of ceratoglossus inferior anticus.
CG.L. = Ceratoglossus lateralis.
TH.H.A. = Thyrohyoideus accessorius,
HG.O. = Hypoglossus obliquus.
TH.G. = Thyroglossus.
= Extension along the whole length of the hypobranchial.

Extension along that fraction of the length of the hypobranchial (anterior end implied).

IH nef cH! cefro Celz9

2% = A little less than 3, but more than {.

2’ = A little more than 3.

O = The inner portion of the ceratoglossus inferior anticus is most fully developed, and reaches not
only to the middle line of the basihyal but extends back along the urohyal. (Retrogression
has not commenced.)

I = As in O, but does not extend back along the urohyal.

II = That stage of retrogression when the muscle no longer reaches the middle line and does not
extend inwards more than about midway between I and III, ¢.e. midway between the tendon
of the ceratoglossus inferior and the middle line,

III = The inner portion has undergone complete retrogression, so that the ceratoglossus inferior
anticus does not extend to the inner side of its tendon (cg.i.a’. has wholly disappeared),

Q = Absence of ceratoglossus inferior posticus and implies a “ unipars” type of muscle.

266 MR. G. P. MUDGE ON THE MYOLOGY

THE EXTENSION OF |
Tw» Byoweriox ov rup‘Tespox or run | TUE Gutaocienss | Fan awousy oy
zc va : ALONG THE or CG.1.A’. |
Hyrosrancutan. |
Stage 9. |
OSUCUNACLG) vio isle we cies eclecies eeir As in the stage next below, but the 3 IL
tendon spreads out in a fan-like form
over the surface of the ceratoglossus |
inferior posticus.
Stage 8. |
WG CORRES ogonooo0a0o0DUDODGS As in the stage next below, but the 3 | JNUE
Lorius flavo-palliatus.. eee eecececees tendons are more strongly developed 3 | THE
5 COMA 5 3.006000000000000006 and extend more posteriorly. 3 | Il
Stage 7. |
CGI 60 Siar O Oe a reecthotke The ventral fascia of the cerato-| _ 3 Il
IRD” soogudaccavood pong d4K0 glossus inferior anticus is no longer 3 | between II & III |
Cyanorhamphnus ....ceeecerececceces tendinous, so that the tendons of this 2 WL |
INA MUPRACUSTNateledoeheterisverarekereheeerel-ictei=t= muscle and of the lateral ceratoglossal 3 | it
Pyrrhulopsis splendens .......++++ ...-| are separated, except at their common 5 | between 1 & IL |
ss FOTW ooo gnoon0EFes origin. | z Il |
UGOTACULUS RU Aet EAR Io eae le clelese oat | 3 | between IL & III
| Pyrrhura ......-.-- pudcbadoocdd oe 3 | Il |
Stage 6. |
IRE so dnnacdac0cng0000000000 The ventral fascia of the cerato- a | Il
PUG CERCUSIletaloloiarals/-loklelelohe|asctalsy eel i= glossus inferior anticus is still tendi- 3 Tit
OCR MMAR ooonconoggo0deconudd nous, but the tendon is more strongly = | between II & IM]
IE NOGWOS do ocacabdocenuousocuoc developed than in the stage next 2 | I
Raniygnathiusmumrrrer cic ceciecerT: below. | 3 Il
ECONO PSVELACUS MT etoreT-folekey- deer kerelet ts 3 I
TTD cig OOS Gam Oats 2 nearly 10
Pozocephalus robustus .....essseeeeeee + i
Ok MM epelieta eee eee 3 | TI
7 BRS (HERS ot ois ONO C9 Oa OE RO CREO DIOS 1&3 | Il
INASP TOMA 5accoou0005000D00005 3 iL
Stage 5. | |
IEFVONWOD soodeodaddgossasioe 600006 To a slight extent the thickened 3 Til
DETOURS sosacduscsonocnvagso0KUOT tract in the ventral fascia of the | eu | IL
Conurus holochlorus ............+.0-- stage next below has separated from it | SS IL
i) Gath “scooocovoaccsasnee and is partially a distinct tendon. The | gn | TIL

OF THE TONGUE OF PARROTS.

267

EXTENSION Extension Tun HG.O. D DEGREE OF Prespnce
or CG.L. or HG.O. ns Un b ANAND DEVELOPMENT OF or ABSENCE OF Ortain or TH.G.
atone HB. ALona HB. CRESS DIVIDED Tenpon or HG.O. TH.H.A.
BN BN D V.S. — PA
3 an D S. Le PA
BN 4 D 8. — PA
BN 3 D 8. — PA
3 aN D 8. -- PP
WM aN D 8. = PP
BN Bn U VS. = PP
2 2 D s. = PP
2 4 D S. — Tee
# 4 D 8. — ee
2 2 D? ES. — | OK
an 2 U FS. — Oz
gn 3 D S. & B. — J22
3" Y D FS. af pp
a 8) U 8. “= PP
BN an D (incipient) 8. & B. — PP |
2! 1 D W. = OE |
2 & # (between) 3 D 8. & B. — OL |
2 & & (between) BN D S. = OE
at a D T.F. ) at insertion 12 OK & PP
2 iL D T.F.J only. 2 OE & PP
BN BN D FS. — OE
a 4 U S. iP OL
4 3 U W. — | PP
4 aN U Absent. — | OEE PP
an 1 D F.TS. & B. — | OF & PP
BN ZN D W.T.F. — Or

VOL, XVI.—PART

vy. No. 8.—October, 1902.

2Q

268 MR. G. P. MUDGE ON THE MYOLOGY
TABLE
| TUE EXTENSION OF |
Tue Evoivrion or tie Texpon or tue | 7? Cem AR OGUGED LE | one SO UNTIOy,
CERATOGLOSSUS INFERIOR, sais ars | Se Hema
THyroprancutan.
Stage 5 (continued). |
Conurus cactorum .. ccc cee c cece eees thickened tract is slightly more pro- | an I
Palcornis torquatd......-eee cece eeee nounced, Bi} between IL & III
qY Bi
Brotogerys (right hand) .....-..++.++- 2N Ir
IPSULEACUS elo olefonolofotorels cline tons iselaesal 2 II
{ Eclectus ....+- sapopdDocoRcnaOOOONE 4 Il
Coracopsts 2... 220s rece snes crccsnns 1 I
Stage 4.
Chrysotis viridigen@ s+... eee eens ineitecentcr loseustinfecioripostiens 2 between I & II
an CRibligo 0600 0d00800000008> is inserted to a slightly thickened, 3 II
i PANAMENSIS 62 wees ee eeee elongated tract in the ventral ten- L I
oF ochrocephala ......-++++e-s- dinous fascia of the ceratoglossus 2 IL
Cyanolyseus patagonicus...... +++. 0e- inferior anticus. This tract fore- 7 I
JRUSNGHY go nd d600 0600 50 U0CD CH OONS shadows the formation of the distinct 4 I
Microglossus 1... 0. ..esseacteeeeees tendon of higher stages. 4 I
Oleh im Booaapoc doocoaDodD ad 1 e)
Stage 3.
MGUUTED. ob ocooogdagadbabecooaDad The ceratoglossus inferior posticus 4 O
Nasiterna pusto .....50--+2000e ees has separated from the parent muscle | 4 I
Oalopsitiacusmet wry cr ier: .-|(cg.i.a), but is still connected with | 3 I
Gacatuanleadbeaten: merrier reer cccehereks the tendinous fascia of that. | 3 O
GUMTRED sdoo0dcoccsga005K00 3 O
Stage 2.
Cacatunigalenctararns rarely: The ceratoglossus inferior anticus q O
has grown back upon the hypobran-
chial, and forms a very rudimentary |
ceratoglossus inferior posticus. Other-
wise as in Stage 1.
|
Stage 1. | |
ARGC saab onondge05000KGde The muscle is composed of the | 0 | i
Cacatua roseicapilla ...............- ceratoglossus inferior anticus only: | 0 O
H GIN) Ssson00000d0b00090n000 the inner part is strongly developed, | i) O
Calyptorhynchus funereus .... 602. .00- and the ventral fascia is tendinous. 0 O
aa ips Goa00c00 00006 0 O

(continued).

OF THE TONGUE OF PARROTS.

Exrnnston Exteysion F : Ducreer or PRESENCE
or OG.L. or HG.O. iia LEO? Dia DEVELOHIRE oF oR Macueck oF Ontein or TH.G.
atone HB. ALone HB. on UNDIvIDED. Tunpon or HG.O. TH.H.A.
ZN 4 U Absent. — OE
a Z D WwW. — OL
2 To head of HB. U Absent. ses OE
4 a 3 D 50 — OL & PP’
BN 3 U W. 12 OL
2 4 U W.T.T. — Jey
2 IN D T.F. at origin. = Intermediate ig
2 } D ye ie a OL
2! + D 8. & B.T.P. as OL
Bh) iN D W.T.T. — OL
$ 3 D W.T.F. = Or
1 Head of HB. U bei = OE
iN a s D Absent. P OL
4" 2 ” D ” P OL & PP’
b To head of HB. U 13eIN Pp OL & PP!
7 qn D aaa Pp OL & PP!
2 Head of HB. U is P OL
+ aN U Absent. Pp OL
L + U op iP OL
4 z U Absent. iP OL
4 uN U Mogi = OE
4 4 U Absent. IP OL
a Head of HB. U . P OL & PP’
3 Ss U 7 P OL & PP’
ar 5 D nS P? OL & PP!?

270 ON THE MYOLOGY OF THE TONGUE OF PARROTS.

LEADING REFERENCES ALLUDED TO IN THE Trex.

(1) C. Giesei.—Die Zunge der Vigel und ihr Geriist mitgetheilt. Zeit. fir Naturwiss. vol. x1.
1858, p. 19.

(2) Cur. Nirzsex.—Znr Anatomie der Papageien, nach Chr. Nitzsch’s Untersuchungen mitgetheilt
yom C. Giebel. Zcit. fiir Naturwiss. vol. xix. 1862, p. 133.

(3) R. W. Suurerpr.—Osteology of Conurus carolinensis. Journ. Anat. & Phys. vol. xx, 1886,
p- 407.

(4) H. Gavow.—Bronn’s Klass. und Ordnung. d. Thier-Reichs. “ Vogel,” 1891, i. Anat. Theil.

(4/) H. Gavow.—Bronn’s Klass. und Ordnung. d. Thier-Reichs. “ Vogel,” 1893, 11. System. Theil.

(5) Brpparp and Parsons.—On certain Points in the Anatomy of Parrots bearing on their Classi-
fication. P. Z. S. 1893.

(6) Sr. Gzorce Mivarr.—On the Hyoid Bone of certain Parrots. P. Z. S. 1895.
(7) Sx. Grorer Mivarr.—On the Hyoid Bone of Nestor and Lathamus. P. Z. S. 1896.
(8) P. Cuatmers Mircuett.—A Contribution to the Anatomy of the Hoatzin. P. Z. S. 1896.
(9) R. W. Suurerpr.—The Myology of the Raven. London and New York, 1890.
(10) Brpparp and Cuatmers Mitrcuett.—On the Anatomy of Palamedea cornuta. P.Z. 8.1894,

p- 536.

(11) T. Satvapor1.—Catalogue of Parrots in the Collection of the British Museum (Cat. Birds,
VOlipxxe |S Oe

(12) F. E. Bepparp.—The Structure and Classification of Birds. London, New York, and
Bombay, 1898.

INDEX TO LETTERING ON PLATES.

ce. = point of origin of eg.i', from cg.i.a. seh. = serpihyoideus.
cg.it. = ceratoglossus inferior anticus accessorius. se.h.a, = anterior division of sere tnyondes
Gaity = secundus. se.h.p. = posterior eS
eg.i*, = part of eg.i.p. becoming or that has become separated | se.h., st.h. = common origin of 'serpihyoideus and_ stylo-
from the parent muscle. hyoideus.
og.ia. = ceratoglossus inferior anticus. sh, =sternohyoideus,
i.a'. = inner portion of eg.i.a. st-.h, = stylobyoideus.
cg.i.a*. = the part of cg.i.a, that arises from the urohyal. ten. = tendon joining the mesoglossus and superior cerato-
ceg.i.p. = ceratoglossus inferior posticus. glossus.
cg.i.p'.= the posterior extension of eg.i.a, that forms the rudi- | tg. = tongue.
ment of ¢g.i-p. th.h. = thyrohyoideus.
eg.l, = ceratoglossus lateralis. th.h.a. = es accessorius.
Coc — superior. th.h.a.t. = rs transversalis,
Czss. — ” sub-superior. th.g. = ~ thyroglossus.
cg.s.a, = superior accessorius. thet, = that part of thyroglossus which has withdrawn from
ch = = ceratohyoideus. its origin at the parahyal process.
c.t. = connective tissue. u.ten, = uro-hy pobranchial tendon.
iG = persistent fascia of the retrogressed portion of the a =ceratoglossus inferior posticus ventralis.
anterior division of the anterior mylohyoideus. jj = 5 . dorsalis.
fp. =persistent fascia of the retrogressed portion of the Y = » _ Medius.
posterior division of the anterior mylohyoideus. IND = mrnterion end of antero- -posterior ridge of basihyal.
gg. = insertion of genioglossus. A.L.P.= anterior lateral process of entoglossum.
gh.a, = anterior geniohyoideus. | BH. = basibyal.
ghia}, & gh.a*, = anterior and posterior divisions of gh.a. CB. = ceratobranchial.
gh.p. = posterior geniohyoideus, EN. = entoglossum.
hg.o. = hypoglossus obliquus, HB. = hypobranchial.
yen = a rectus. P.A, = parabyal arch.
ins. = insertion of outer extremity of anterior division of | P.P. = EPROCesS:
serpihyoideus. N. =nodule (sometimes bony, but usually cartilaginous)
ml. = membrane of tongue. articulating with the yentral surface of uruhyal at
mh.a. & mh.a!. = anterior and posterior divisions respectively its root,
of anterior mylohyoideus. } UR: =urobyal.
ing. & mg’. = mesoglossus or tissue occupying place of meso- T, = trachea.

glossus respectively,

’

GaN NOXOW TL

VoL, XVI.—Ppart v. No. 9.—October, 1902.

MYOLOGY OF THE TONGUE OF PARROTS.

PLATE XXVI.

Vig. 1. Hos viciniata. Ventral view, after removal of the skin. On the left the inner portion of serpihyoidens

Fig.

Fig.

On

on)

~T

i.)

has been removed and the muscles slightly separated to show their relations in the otherwise
undisturbed condition. (Magnified 13.)

. Stringops habroptilus. Ventral view, after removal of the skin. (Reduced 3.)
«, 3. Psittacus erithacus. Ventral view. On the left, one-half of the lower bill has been removed, as well as

the persistent fascia (7.), which is a backward prolongation of the anterior portion of the anterior
mylohyoideus. (Ieduced 3.)

. Cacatua galerita, Ventral view. The fascia (f.) of the left side has been removed to show the similar

but very unusual one (f.p.) Which is continued back from the posterior division of the muscle.
(Reduced 3.)

. Platycercus evimius. Ventral view after removal of the skin. On the left, one-half of the lower jaw

has been removed. (Magnified 13.)

. Ptistes erythropterus, As in fig. 10, except that the thyrohyoideus is not hidden. (Magnified 13.)
. Paleornis torquata. Dorsal view, after removal of the membrane of the tongue. ‘The trachea and

larynx have been turned over to the right, and only sufficient of the stylohyoideus and sterno-
hyoideus represented to show their insertions. ‘The geniohyoideus has been removed upon the
right. (Magnified 13.)

. Pezoporus formosus. Dorsal view, with the trachea and most of the muscles in situ. On the left, the

sternohyoideus, stylohyoideus, and serpihyoideus have been removed, and the thyroglossus cut
through near its insertion and reflected outwards, in order to reveal the thyrohyoideus and cerato-
glossus superior. The posterior mylohyoideus has been represented on the right, in order to
especially indicate the very slender insertion of the stylohyoideus and the contracted origin of the
inner portion cf the serpihyoideus. The geniohyoideus has been removed upon both sides.
(Magnified 23.

. Conurus jendaya, Dorsal view, after removal of the membrane of the tongue. The trachea has been

turned over to the right and the geniohyoideus of either side removed; on the right the
sternohyoideus and posterior mylohyoideus have also been removed. On the left only enough of

the stylohyoideus has been left to show its insertion, and the serpihyoideus has been removed.
(Magnified 13.)

10. Paocephalus rtippelli. Dorsal view, with the muscles and trachea i situ, and only sufficient of the

stylohyoideus represented to show its insertion. The thyrohyoideus is hidden beneath the thyro-
glossus. (Magnified 23.)

Vig. 11. Platycercus evimius. As in fig. 17, except that the mesoglossus is not cut and the origin of the

thyroglossus is intact. (Magnified 2.)

H,Grénvold. del.

_s.h

WW seh.a

Trans. Zook. Yor. Vok, XVI FE. XXV,

mh.a}

MYOLOGY OF THE TONGUE OF PARROTS.

_-mh.a

~ mh.al

Photoprint by Bale «Danielsson

Tig.

Fig.

12.

. 1d.

. 16.
g. 17.

ig. 19.

MYOLOGY OF THE TONGUE OF PARROTS.

PLATE XXVII.

Chirysotis ochrocephala, Dorsal view. The trachea has been turned over to the right in order to
show the origins and insertions of the thyrohyoideus and thyroglossus, the latter of which
has no real origin, but lies free in the middle line above the basihyal. On the left only
a portion of the stylohyoideus has been represented sufficient to show its insertion and general
course. The geniohyoideus and sternohyoideus have been removed upon the right. (Mag-
nified 14.)

3. Cacatua galerita. Dorsal view, with the trachea turned over to the right and only sufficient of the

stylohyoideus represented upon the left to show its insertion. The genichyoideus has been removed
upon both sides. (Magnified 13.)

Chrysotis panamensis. Dorsal view. The trachea has been turned over to the right in order
to show the origins and insertions of the thyrohyoideus and thyroglossus, and the peculiar
connection of the latter with the sternohyoideus. Only sufficient of the stylohyoideus has been
left to show its insertion. ‘The genioglossus has been removed upon both sides. (Magnified 13.)

. Psittacus erithacus. Dorsal view, but with the trachea turned over to the right, and with the

thyroglossus dissected away from its origin, in order to reveal the thyrohyoideus. Upon the
left, but not upon the right, the full extent of the posterior mylohyoideus and sternohyoideus
has been represented. The geniohyoideus has been removed upon both sides. (Magnified 12.)

Psittacus erithacus. Dorsal view, with the muscles and trachea in situ. (Magnified 13.)

Coracopsis vasa. Dorsal view, with the trachea reflected to the right and the origin of the thyro-
glossus cut through and turned back in order to reveal the thyrohyoideus. A portion of the
mesoglossus muscle has been cut away in order to indicate the mode of termination of the cerato-
glossus superior in its sheath. On the left only sufficient of the stylohyoideus has been
represented to show its insertion. (Reduced j.)

. Stringops habroptilus. Dorsal view. The trachea and larynx have been turned over to the right

and the thyroglossus partially dissected away from its insertion and raised up, in order to reveal
the thyrohyoideus. On the right the serpihyoideus and the greater part of the stylohyoideus and
the sternohyoideus have been removed. The geniohyoideus has been similarly removed upon both
sides. (Magnified 13.) :

Pyrrhura leucotis. Dorsal view. The trachea has been turned over to the left and only sufficient of
the stylohyoideus represented upon the right to show its insertion. The geniohyoideus has been
removed upon both sides. (Magnified 13.)

20. Ara macav. Dorsal view. The trachea has been turned over to the right and a portion of the

membrane of the tongue left, in order to show the partial insertion of the thyroglossus to it. The
stylohyoideus and geniohyoideus have been removed upon both sides. (Reduced 3.)

. Lorius domicella. Dorsal view, after removal of the trachea, thyroid, and membrane of the tongue.

The muscles have been dissected out and pulled slightly apart in order to show their relations
to the hyoid bone. On the left the thyroglossus, thyrohyoideus, and sternohyoideus have been
removed; and on the right the lateral ceratoglossal, hypoglossus obliquus, and geniohyoideus.
On the right also the thyroglossus and thyrohyoideus have been cut through and enough left
to show their origin from the parahyal arch. (Magnified 13.)

. Nestor notabilis. Dorsal view after extraction from the head and remoyal of the membrane of the

tongue. The trachea and thyroid have been turned over towards the right to show the insertions
of the thyroglossus, thyrohyoideus, and thyrohyoideus accessorius. The genioglossus has been-
removed upon both sides. (Reduced 3.)

3. Loriculus galgulus. Dorsal view after removal of the membrane of the tongue. The trachea has

been reflected to the right in order to show the origins and insertions of the thyroglossus and
thyrohyoideus. On the right, only sufficient of the stylohyoideus has been represented to show
its insertion. The serpihyoideus and geniohyoideus are not represented on either side.
(Magnified 2.)

Trams. Loot. Soe. Vot. XVI Ft. XXVIL

prone oramiaels MYOLOGY OF THE TONGUE OF PARROTS. Photoprint by Bale «Danielsson Lt!

ey

Fig.

Fig.

Fig.

Fig.

Fig.

g. 26.

29.

30.

ig. 33.

ig. 34.

8. 36.

MYOLOGY OF THE TONGUE OF PARROTS.

PLATE XXVIII.

4. Ara ararauna. Ventral view after extraction from the head and removal of the anterior

mylohyoideus. On the right, the posterior mylohyoideus (serpi- and stylohyoideus) and sterno-
hyoideus have been removed; the geniohyoideus has been similarly removed upon the left.
(Reduced }.)

Cacatua galerita. Ventral view of the hyoid apparatus after extraction from the head. On the
right, the serpihyoideus, stylohyoideus, and ceratohyoideus have been removed, and the uro-
hypobranchial tendon and ceratoglossus inferior accessorius have been reflected to one side. The
sternohyoideus has been removed from both sides. (Magnified 12.)

Stringops habroptilus. Ventral yiew of the hyoid apparatus after removal from the head, On the
right, the serpihyoideus, stylohyoideus, ceratoglossus inferior accessorius, uro-hypobranchial tendon,
and ceratohyoideus have been removed. The sternohyoideus and geniohyoideus haye been
removed from both sides. (Magnified 14.)

. Ara macao. Ventral view, after removal of the mylohyoideus anterior. On the left, the cerato-

hyoideus and posterior mylohyoideus have been removed, and the uro-hypobranchial tendon and
ceratoglossus inferior anticus accessorius have been reflected to the left. Upon both sides the
sternohyoideus has been removed. (Reduced 3.)

Chrysotis ochrocephala. Ventral view of the hyoid apparatus after extraction from the head and
removal of the anterior mylohyoideus. On the left, the posterior mylohyoideus has been removed,
the ceratoglossus inferior anticus accessorius turned forwards, and the ceratohyoideus partially
dissected away, in order to reveal the ceratoglossus inferior posticus. The sternohyoideus and
geniohyoideus have been removed from both sides. (Magnitied 13.)

Psittacus erithacus. Ventral view of the hyoid apparatus after extraction from the head and removal
of the anterior and posterior mylohyoideus. On the left, the ceratohyoideus, sternohyoideus, and
geniohyoideus have been removed, and the uro-hypobranchial tendon and ceratoglossus inferior
anticus accessorius have been reflected. On the right, the ceratohyoideus, ceratoglossus inferior
anticus and posticus, ceratoglossus lateralis, and sternohyoideus have been removed, in order to
show the relation of the hypoglossus obliquus to the basihyal and hypobranchial. (Magnified
13.)

Conurus cactorum. Ventral view atter removal of the anterior mylohyoideus. On the right, the
posterior mylohyoideus and ceratohyoideus have been removed, and the uro-hypobranchial tendon
and ceratoglossus inferior accessorius reflected to one side. The geniohyoideus and sternohyoideus
have been similarly removed upon both sides. (Magnified 13.)

. Coracopsis vasa. Ventral view, after removal of the anterior mylohyoideus. On the right, the

posterior mylohyoideus (serpi- and stylohyoideus) and ceratohyoideus have been removed, and
the uro-hypobranchial tendon and ceratoglossus inferior anticus accessorius have been reflected.
(Reduced 3.)

. Paleornis torquaia. Ventral view. On the right, the posterior mylohyoideus and sternohyoideus

have been removed, and the uro-hypobranchial tendon and ceratoglossus inferior accessorius have
been reflected to the right. The geniohyoideus has been removed from both sides. (Magnified 12.)

Brotoyerys pyrrhopterus. Ventral view. On the left, the posterior mylohyoideus, ceratohyoidens,
and sternohyoideus have been removed, and the uro-hypobranchial tendon and ceratoglossus
inferior accessorius have been reflected. On the right, the ceratohyoideus has been left in situ,
and the ceratoglossus inferior accessorius and uro-hypobranchial tendon are undisturbed. The
geniohyoideus and anterior mylohyoideus have been removed from both sides. (Magnified 14.)

Psiitinus incertus. Ventral view. On the left, the posterior mylohyoideus, uro-hypobranchial tendon,
ceratoglossus inferior accessorius, and ceratohyoideus have been removed in order to show the
ceratoglossus inferior posticus. Upon both sides the sternohyoideus, anterior mylohyoideus, and
geniohyoideus have been removed. (Magnified 12.)

. Ptistes erythropterus. Ventral view of the hyoid apparatus efter removal from the head. On the

left, the posterior mylohyoideus, ceratohyoideus, uro-hypobranchial tendon, and the ceratoglossus
inferior accessorius have been removed. The geniohyoideus and sternohyoideus have been similarly
removed from both sides. (Magnified 12.)

Conurus jendaya. Ventral view after extraction from the head and removal of the anterior mylo-
hyoideus. On the left, the posterior mylohyoideus and ceratohyoideus have been removed, and
the ceratoglossus inferior accessorius and uro-hypobranchial tendon have been reflected to one side.
Upon both sides the sternohyoideus and geniohyoideus have been removed. (Magnified 13.)

Trans. Loot. Soc. Vol. XVI. FE. XXVUL.

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H.Gronvold. del. MYOLOGY OF THE TONGUE OF PARROTS. Photoprint by Bale «Danielsson Lt! |

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Fig. ¢

Tig. 42.

Fig.

ig. 39.

ig. 40.

ig. 41.

nad:

MYOLOGY OF THE TONGUE OF PARROTS.

PLATE XXIX.

Lovius domicella, Tyoid apparatus removed from the head and its muscles dissected from the ventral
aspect to show their relations to the various portions of the hyoid bone. The anterior and
posterior mylohyoideus and the geniohyoideus have been removed. On the left side the cerato-
hyoideus, hypoglossus obliquus, and rectus have been dissected off, and on the right the lateral
and inferior ceratoglossals were similarly removed. (Magnified 13.)

. Lorius flavo-palliatus. Ventral view of the hyoid apparatus after removal from the head. On the

right the lateral and inferior ceratoglossals have been removed, and on the left the membrane of
the apical portion of the tongue and the ceratohyoideus, The anterior and posterior mylohyoideus,
geniohyoideus, and serpihyoideus have been dissected off. (Magnified 1}.)

Eos riciniata. Ventral view after removal from the head. The anterior and posterior mylohyoideus
(serpihyvideus and stylohyoideus) and sternohyoideus have been removed, and on the right the
ceratohyoideus and geniohyoideus also. (Magnified 13.)

Pyrrhura leucotis, Ventral view. On the right the serpihyoideus, stylohyoideus, and sterno-
hyoideus have been removed, and the uro-hypobranchial tendon and ceratoglossus inferior accessorius
reflected to the right. The geniohyoideus has been removed upon both sides. (Magnified 13.)

Psittacula passerina. Ventral view. On the right, the posterior mylohyoideus, uro-hypobranchial
tendon, ceratoglossus inferior accessorins, and ceratoglossus inferior accessorius secundus have
been removed. ‘he sternohyoideus and geniohyoideus have been similarly removed upon both
sides. (Magnified 23 nearly.)

Loriculus galgulus. Ventral view. On the right, the posterior mylohyoideus, sternohyoideus, and
ceratoglossus inferior accessorius have been removed. (Magnified 2.)

. Pionopsittacus pileatus. Ventral view. On the left, the posterior mylohyoideus, the ceratoglossus

inferior anticus, and the uro-hypobranchial tendon have been removed. The geniohyoideus and
genioglossus have been removed upon both sides. (Magnified 14.)

. Platycercus ecimius. Ventral view. On the right, the serpihyoideus and stylohyoideus have been

removed, and the uro-hypobranchial tendon has been cut through at its inner attachment, and
together with the ceratoglossus inferior accessorius reflected to the right. Upon both sides the
geniohyoideus and sternohyoideus have been removed. (Magnified 12.)

Bolborhynchus lineolatus. Ventral view. On the left, the serpihyoideus, stylohyoideus, sterno-
hyoideus, and geniohyoideus have been removed. ‘The two latter muscles have also heen removed
on the right. (Magnified 14.)

. Nestor notabilis. Ventral view of the hyoid muscles after removal from the head. On the right,

the posterior mylohyoideus, sternohyoideus, and uro-hypobranchial tendon have been removed.
(Reduced 7.)

. Pezoporus formosus. Ventral view after removal of the hyoid apparatus from the head. On the

left, the posterior mylohyoideus and the ceratoglossus inferior accessorius have been removed, and
the sternohyoideus and geniohyoidens have been similarly removed upon both sides. (Magnified 2.)

. Nasiterna pusio. Ventral view after extraction from the head and removal of the anterior and

posterior mylohyoideus. On the left, the ceratohyoideus, sternohyoideus, ceratoglossus inferior
anticus and posticus, and ceratoglossus lateralis have been removed in order to show the
hypoglossus obliquus. On the right, the ceratohyoideus and sternohyoideus have been removed.
Upon both sides the geniohyoideus has been dissected away. (Four times nat. size.)

. Eclectus pectoralis. Ventral view. On the right, the serpihyoideus, stylohyoideus, ceratohyoideus,

and sternohyoideus have been removed, and the uro-hypobranchial tendon and ceratoglossus
inferior accessorius have been reflected. The geniohyoideus has been removed from both sides.
(Magnified 14.)

). Lorius domicella, Lateral aspect of the hyoid apparatus, after extraction from the head and removal

of the membrane of the tongue. The relation of the hypoglossus rectus to the mesoglossus is
better seen than in any other view. (Magnified 11.)

. Loriculus galgulus. Ventral view. On the left, one-half of the lower bill and of the persistent

fascia (f.) has been cut away. (Magnified 14.)

Trans. Loot. Soc. Vol, XVI. FE. XXIX.

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ronvold. dei. MYOLOGY OF THE TONGUE OF PARROTS. Photoprint by Bale «Danielsson Ltt

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CONTENTS.

VL. On the Myology of the Tongue of Parrots, with a Classification of the Order, based
upon the Structure of the Tongue. By Guorcx P. Mupes, 4.2.0.8. Lond., 2.Z.S.,
Lecturer on Biology, London School of Medicine for Women, and Demonstrator of
Biology, London Hospital Medical School. (Plates XXVI-XXIX.) page 211

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VII. On Okapia, anew Genus of Giraffide, from Central Africa. By E. Ray Lankester,
MA., LLD., PRS, F.ZS., Director of the Natural History Departments of the
British Museum, Correspondent of the Institute of France.

Received and read November 19, 1901.

[PLatres XXX.-XXXII.]

ConTEN Ts, Page

lmpistonysomthe Discoverys ofitherOkapic 4-4 -scciencucile ia ae ereiehiienaciei interes sre oo)
lily PheyResionsinhabitedibyacheyO kaput is esol oes ooo eater teiiieiiciicierel etoile 282
IIL. Description of the Skull and Lower Jaw of the Okapi ............-0 cece ee eee cette teens 283

IV. The Areas of Tumescence of the Giraffine Skull and the Nature and Origin of the Horns of Pecora. 291

Ve) Characters! presented) bythe) Skin’ of the!Okapil 3.2). 4... - sell eicieileleisioel sleleiel letilelsielsieierel ar 300
VI. Characters of the Genus Okapia and of the Species O. johnstont ......... 000 e ee eee eee cece es 302
AVAIL MPAR pend ixae ere scistatee torent eiatelays dene ciercas tas are ep Late ee eae nt ga RUNS A Ueopkeal et ea eee rea 304
Vinee xplanationton they blates®cparajsvcrsj-) ldvayesd sarvyateye chee ates are ee reran rors are ecteho meee me eae 309

I.—H story or THE DISCOVERY OF THE OKaArI.

‘THE animal to which this memoir relates is, we are told by Sir Harry Johnston,
who obtained the skin and skulls here described and presented them to the British
Museum, known to the natives in the neighbourhood of the Semliki Forest by the
name “ Okapi.”

The following passage in Sir Henry Stanley’s ‘In Darkest Africa,’ vol. ii. p. 442,
first drew Sir Harry Johnston’s attention to the animal. Stanley says, in reporting on
the language of the Congo dwarfs whom he saw in 1888 :—‘* The Wambutti (these
dwarfs) knew a donkey and called it ‘ Atti... They say that they sometimes catch them
in pits. What they can find to eat isa wonder. They eat leaves.” From conversation
with Sir Henry Stanley during the present year (1901), Sir Harry Johnston has come
to the conclusion that Stanley and his companions occasionally caught sight of the
Okapi when they traversed the region of the Congo forest on the western side of the
Semliki River. His own acquaintance with the animal, which he was led to seek by
Stanley’s brief reference to it as a donkey, is given in the following extracts from a
letter to me dated November 1901. The word “ Atti” given by Stanley is apparently
a variant of the name ‘“ Okapi,” which Sir Harry Johnston found to be the name for
it used by his informants :—

“‘ Somewhere about March 1900 I first heard of the Okapi from the Congo dwarfs
who were staying with me at Entebbe, Uganda. At the beginning of July I reached
the Semliki Forest, in the Congo Free State. The first Belgian official who confirmed the
Okapi stories, and who assisted me to get the bandoliers of skin, was a Lieutenant Meura.

VOL. XvI.—ParT VI. No. 1.— August, 1902. 2s

280 DR. BE. RAY LANKESTER ON OKAPIA.

Lieutenant Meura knew a good deal about the Okapi, though he still believed it to
be a kind of horse. Unfortunately he died soon afterwards of black-water fever. His
second in command at Fort Mbeni, on the border of the Semliki Forest, was Karl
Eriksson, who had been a non-commissioned officer in the Swedish Army and had
become an officer in the service of the Congo Free State. After my fruitless search
through the nearer parts of the Semliki Forest, in which I only got one more strip of
skin from a native, I was obliged to leave the forest owing to the absolute collapse of
my carayan, all the Negro porters having gone down with violent forms of fever. So
completely collapsed were they, in fact, that the Belgians had to turn out all their
soldiers and station-labourers to carry my loads back to British territory. To console
me for my disappointment, Meura promised to use his best endeavours to get a complete
skin. After his death, which took place soon afterwards, Eriksson most generously
carried out that promise. I must have sent home the bandoliers to Sclater in October
1900, as I was a long while getting back to my headquarters.

‘The complete skin sent by Eriksson was probably despatched from the Congo Free
State about February 1901, and arrived in Entebbe in March, reaching me at the end
of that month at the Eldama Ravine, in the eastern part of the Protectorate. In the
original note (which, unfortunately, I cannot at this moment find) that Eriksson sent
accompanying the skin he refers distinctly to the hoofs as though they were on the
skin, describing them as bluish black and like those of an antelope, his point being, of
course, his surprise at discovering the creature not to be a soliped but cloven-hoofed.
When Jackson opened the skin at Entebbe the horny hoofs had apparently disappeared.
At first we thought that they had been eaten by rats, but Doggett (my taxidermist)
suggests that they simply fell off the bones. In other cases we found it constantly
happened, after the foot of a hoofed mammal had become dry, that the horny sheath
fell off the bone. When the skin reached me the lower jaw of the bigger skull was
still attached to it. Eriksson also in his letter said, ‘I send you a skin and skull of
the Okapi,’ &c., and a little later on, ‘also another skull. As the bigger skull
supposed to belong to the skin exactly fits the mandible which actually was attached
to the skin when it reached me, I assume that the larger of the two skulls belongs to
the skin. hat is all I know with regard to this mysterious animal. After I left the
Congo Free State I discussed this question with natives of the little territory of Mboga,
which happens to be British, and is actually part of the Semliki Forest. They all knew
the creature, and declared that it was fairly common in their country. Nevertheless,
although these people have brought us in young elephants, chimpanzees, and all sorts
of other creatures, they have failed hitherto to bring another specimen of the Okapi.”

The strips of skin referred to in this letter as “ bandoliers” were covered with
hair, coloured dark brown and white in alternate bands. They were received in
Lendon in November 1900, and were exhibited by Dr. Sclater at the Meeting of this
Society on December 18th (see P. Z.S. 1900, p. 950). They were again exhibited and

DR. E, RAY LANKESTER ON OKAPIA. 281

Text-fig. 1.

thi
ws, hh

Bandoliers made from the skin of the Okapi.
(From P. Z.8. 1901, i. p. 51.)

described at this Society's Meeting on Feb. 5th, 1901, as indicating a new Zebra, to
which Dr. Sclater gave the name “ Equus johnstoni.” The figure of these ‘ bandolicrs ”
published by Dr. Sclater is here reproduced (text-fig. 1).

i)
™|™
i)

282 DR. E. RAY LANKESTER ON OKAPIA.

The complete skin, which arrived in London in July 1901 and is now mounted in
the gallery of the Natural History Museum (as represented in Plate XXX.), shows
that the striping of the pelt extends over a very limited area, being confined to the
haunches and the fore and hind legs above the carpus and tarsus respectively. The
“ bandoliers ”’ in question are found, on comparison with the complete skin, to have
been cut from the haunches, and their exact position can be traced. A comparison
leaves no doubt that these strips of skin belonged to the Okapi, and therefore the

b)

specific name “ johnstoni” given by Dr. Sclater will remain as the designation of the
Okapi. At the same time, the close study of the bandoliers and the complete Okapi
skin render it certain that the striping on the hind legs of the Okapi is, to a small
extent, variable in individuals.

It was at once apparent to Sir Harry Johnston, on receiving the complete skin with
the double hoof-bones, that the Okapi is not really a horse-like animal at all, but
belonged to the group of Artiodactyle Ungulates. The absence of horns and the great
length of the ears account for the comparison of the animal to a donkey or a zebra
frequently made by natives when describing it. But the examination of the two skulls
and the lower jaw enabled Sir Harry Johnston to recognize before despatching the
specimens to England that the Okapi is closely related to the Giraffes. In the letter
written in April 1901, which he sent to me announcing the fact that he had packed
up and sent off the skin and skulls of the Okapi from Uganda to England, Sir Harry
expresses the opinion that the Okapi is a hornless kind of giraffe and possibly to be
referred to Gaudry’s genus Helladotheriun 1.

As will be seen from the drawing and description of the skulls and lower jaw here
given, the identification made by Sir Harry Johnston was practically correct. Though
the Okapi differs in important characters of generic value from the Helladotherium ot
the Miocene of Pikermi and India, it yet stands close to it as a hornless? representative
of that remarkable and once extensive group, the Giraffide, of which it and the Giraffe
are the only survivors. There were many and varied genera belonging to the Giraffidee
in the Miocene period, some with larger bony outgrowths of the skull than has the
recent Giraffe and some without such outgrowths.

I].—Tue ReGIoNn INHABITED BY THE OKAPI.

Before proceeding to further description of the characters exhibited by the skin and
skulls in our possession, it is well to put on record the nature of the region in which
the Okapi is found. The Semliki River flows from the Albert Edward Lake to the
Albert Nyanza, and it is in the forest on the western side of the river that the Okapi
lives. Sir Harry Johnston estimates the area within which it certainly occurs as being
as large as the Principality of Wales, and it may have a larger range. There are

* See also the ‘Times,’ May 7th, 1901.
* May 27th, 1902,—Now shown not to be hornless ; see Appendix, p. 304.

DR. HE. RAY LANKESTER ON OKAPIA. 283

certainly many thousand individuals of it inhabiting the forest of this region. The
equatorial position of the forest renders the atmosphere extremely hot and damp,
whilst overhead the foliage is so dense that little or no light penetrates to the ground.
There is ample room for locomotion among the trunks of the large trees, and it is
here that the Okapi roams. The Okapi is strictly a forest animal, feeding at the
occasional openings in the forest where decay and storms have broken down the
continuity of dark leafless avenues. The natives are extremely reluctant to penetrate
far into the forest, and hence it is that the Okapi is but seldom seen and is known
chiefly to the Wambutti or Akka, the dwarf race who, like the Okapi itself, seek the
recesses of the forest as a protection against light-loving enemies !.

The peculiar disposition of the striping of the Okapi’s legs and body must be
explained, if explained at all, by a consideration of its habits and surroundings ; and
at present we know no more on those matters than can be derived from the description
given by travellers of the heat, moisture, gloom, and silence, as well as the enormous
extent, of the Semliki and Congo forests.

III.—DeEscription OF THE SKULL AND Lower JAW OF THE OKAPI.

As the form and characters of the skull are those which are important in determining
the affinities of the Okapi and in characterizing the genus Okapia, I shall describe
these before proceeding toa consideration of the skin, the features of which may, in
many respects, be only of specific value. One of the two skulls sent is considerably
larger than the other, and belongs to the skin, the lower jaw having been still attached
to the latter when received by Sir Harry Johnston.

The skulls are figured in Plates XXXI. and XXXIL., two-thirds of the natural
size.

The state of the dentition of the larger skull indicates that it is that of an animal
far from mature and corresponds to that of a Giraffe of two-thirds the linear
measurements of an adult. ‘This fact has an important bearing upon the conclusions
we may form as to the absence of horns, especially when taken into consideration
with the fact that there was no evidence in the skin as sent home as to the presence
of male or female generative organs. The skull and skin may be those of an
immature male or of an immature female. In Giraffes, however, of much less than
two-thirds growth the lateral horn-bones (“‘ossicusps”) are present as separately
ossifying cones. And it seems probable from the fact that none of the native reports
concerning the Okapi refer (according to Sir Harry Johnston) to the existence of

1 The Okapi is not unfrequently captured in dug-out traps and speared by the natives in the neighbourhood of
the Independent Congo State fort whence Sir Harry Johnston obtained it. It is not an animal which can attract

the sportsman, on account of the heat and darkness of the forest where it lives; but I have no doubt that
anyone who would go and stay six months or more on this spot would be able to obtain several complete

specimens without firing a shot.

284 DR. E. RAY LANKESTER ON OKAPIA.

horns, but rather emphasize their absence by comparing the animal to a horse, that
no horns are ever developed in either male or female Okapi}.
Given an animal which, as shown by the skin, possessed no rudimentary digits by

Text-fig.

bo

Lateral view of the skull of the Okapi, the individual being about two-thirds grown, to compare with
the similar figure of a Giraffe’s skull (text-fig. 3).
occ., occipital crest ; .t./., position of the lateral parietal tumescence and epiphysis of the Giraffe, absent here ;
sfp., fronto-parietal suture ; ot/., the lateral frontal tumescence of the Okapi, absent in Giraffe ; otm.,
the median basinasal tumescence of the Okapi; plv., prelacrymal vacuity ; p.h., palatine horizontal.

Text-fig. 3.

Lateral view of the skull of a Giraffe, about two-thirds grown, to compare with the similar view of the Okapi’s
skull, which also appears to have belonged to an individual which had completed only two-thirds of its
growth.

occ., occipital crest ; p.oss., parietal osseous cap (epiphysis) overlying the parietal conical upgrowth ; sfp.,

fronto-parietal suture ; 0.t./., position of the lateral frontal tumescence in the Okapi, absent here ; g.t.m.,
the characteristic median tumescence of the Giraffe’s frontal, devoid in this specimen of any secondary
cap or epiphysis, absent in the Okapi ; plv., the prelacrymal vacuity ; p./., palatine horizontal.

the side of the main paired hoof-bearing digits—what are the characters of the
skull which in the first instance enable us to refer the specimen to the Giraffide ?
In the first place, the general characters of the dentition—absence of incisors and

* See Appendix and text-figure on p, 304, giving an account of two new specimens, male and female, with
horns two to three inches in length.

DR. E. RAY LANKESTER ON OKAPIA. 285

canines in the upper jaw, the presence of brachydont selenodont molars, the group
of eight anterior teeth in the lower jaw (incisors and canines), and the long diastema
between these and the molars—are characters only found in the Pecora and in
typical Giraffidee (Vellericornia), Cervidee (Cervicornia), or Bovidee (Cavicornia). The
absence of ‘“pettitoes” renders Cervine and Bovine affinities improbable, whilst
Antelopine and Giraffine are more likely. Antelopes without rudimentary digits are
known, but are exceptional. The absence of horns would tell no more against Antelopine
than Giraffine affinities, since hornless females are known among the former.

The great length of the postorbital region of the Okapi’s skull (text-fig. 2, p. 284)
is, however, not at all Antelopine, and is more nearly approached (though not nearly
equalled) by the Giraffe. Moreover, the skull of the Okapi is not only astonishingly
long in the postorbital region (see Plates XXXI. & XXXII.), but it presents a great
peculiarity in the fact that this region is in the same horizontal plane as the preorbital
region. In fact, the basicranial axis and the basifacial axis of the Okapi’s skull appear

Text-fig. 4.

Lateral view of the skull of Helladotherium, from the Miocene of Pikermi: after Gaudry.

oce., occipital crest; p.h., palatine horizontal; m.p.b., median parietal boss or tumescence, similar in character
to, but differing in position from, the lateral bosses of Giraffe or of Okapi or the median boss of Giraffe.

to lie nearly (not quite) in one plane. ‘This is a primitive and an unusual character.
It is more or less retained by the genus Alces (text-fig. 6, p. 286) and others of the
Cervidee, where the planes of the two axes form a very open angle; but in the Bovide
a much less obtuse angle is formed by the plane of the basicranial axis where it meets
that of the basifacial axis (text-fig. 8, p. 287).

The whole of the brain-case or postorbital region of the skull of the Bovide appears
to be bent down as on a joint formed across the junction of the cranial and facial portions
of the skull (see text-figs. 7 and 8, p. 287). This bending down or angulation of the
brain-case has occurred to some extent in Giraffa, as shown in the section (text-fig. 5,
p. 286), but much less than in the Bovide. Although our specimens of Okapi’s skull
have the basis cranil broken away, we can yet conclude confidently from the relations
of the roof and sides of the cranium that there was a complete absence of any such
bending or of any angle at the junction of the basicranial axis with the basifacial axis.

286 DR. E. RAY LANKESTER ON OKAPIA.

There is good ground for connecting the presence of the deflection of the cranial
cavity, above noted, with the mechanical conditions arising from the use of horns
having the position and direction of those found in Bovide and the Giraffe. Even in
the hornless females of certain Antelopes the deflection is maintained (text-fig. 7,
p. 287). ‘The absence or small size of the deflection is almost certainly to be regarded
within the group Pecora as a primitive character, and in the horizontality of the skull
or tendency to coincidence of the basicranial and basifacial axis-planes the Okapi bears

Text-fig. 5.

CGE

Vertical longitudinal section of the skull of a Giraffe, to show the air-sinuses and the relatively low angle
formed by the basicranial axis (¢.a.) and the palatine horizontal (p.h.).

occ., occipital crest ; p.oss., parietal ossicusp; g.t.m., Giraffe’s median tumescence, upon which the median
osseous cap develops,

Text-fig. 6.

Vertical longitudinal section of the skull of a female Elk (Alces), to show the Jow angle formed by the
basicranial axis (¢.a.) and the palatine horizontal (p.h.).

oce,, occipital crest.

evidence of (1) being relatively primitive, (2) not having had horn-bearing forebears,
(3) of being remote from the Cavicorn stock.

A further character, at once obvious on examination of the Okapi’s skull, is the
absence of the lacrymal fossa—present in many Antelopes and all the Cervide, but absent
in Giraffes. This, however, is not a diagnostic character, since the lacrymal fossa is
not present in all Antelopes. Equally inconclusive is the existence of the ‘‘prelacrymal
vacuity ” (Pl. XXXII. fig. 12, c), which is well marked in the Okapi’s skull and in all

DR. E. RAY LANKESTER ON OKAPIA, 287

Giraffe skulls, except those of old individuals. The prelacrymal vacuity occurs in other
Pecora besides the Giraffe, being well developed both in Alces and in Antilocapra and
other Cervidee and Bovide.

We have not so far found any character, beyond the general shape of the skull,
which tends to associate the Okapi with Giraffide rather than with Bovide or Cervide.
And, as a matter of fact, though an enumeration of details, such as shape of the nasals
and each of the cranial bones, the absence of lacrymal fossa, and presence of prelacrymal

Text-fig. 7.

ZAR CICL
GA

Vertical longitudinal section of the skull of a female Water-buck (Kobus ellipsiprymnus), to show the high
cranio-palatine angle in a hornless Bovid.

c.a., basicranial axis ; p.h., palatine horizontal.

Text-fig. 8.

Vertical longitudinal section of the skull of the Domestic Goat (Capra), to show the high angle formed
by the cranial axis (c.a.) and the palatine horizontal (p.h.).

occ., occipital crest.

vacuity, would result in a totality of agreements with Giraffa greater than with any
other form, still we have not yet mentioned any one character peculiar to Giraffa
which also is found in Okapia. ‘There is, however, such a character, and this is found
in the peculiar bifoliate form of the crown of the lower incisor on each side. If we
compare the group of eight teeth forming the biting-apparatus of the lower jaw in
Giraffa and Okapia, we observe that the group of teeth is relatively larger and more
widely spread (in proportion to size) in the former than in the latter. The group of
VOL. XVI.—PART VI. No. 2.—August, 1902. 27

288 DR. E. RAY LANKESTER ON OKAPIA,

“

teeth is a flatter more spatula-like structure in the Giraffe than in the Okapi. In the
Okapi the group is relatively small, and the individual teeth not only actually smaller
but, relatively to the size of jaw and skull, very much smaller than in Griraffa'. ‘They
do not form so flat or horizontally depressed a group: there is, on the contrary, a marked
concavity within the margin of the group of teeth. ‘This difference in the relative size
andin the shape of the group of incisive teeth of the lower jaw points to some marked
difference in the food of the Okapi as compared with that of the Giraffe. We do not
know, as yet, on what the Okapi feeds, but it is certainly not the same vegetable
erowth as that which is sought by the Giraffe. Nevertheless, whilst there is a marked

Text-fig. 9.

TZ Wy:
Wii

Canine teeth of Giraffide, all of the natural size.

A. Right permanent canine and three incisors of Giraffe.
B. Right deciduous canine of young Giraffe.
C. Right permanent canine of Okupia johnstont.
D. Right permanent canine of Samotherium (Palwotragus).
E. Right permanent canine of Sivatherium.
These drawings were made under my superintendence from original specimens preserved
in the Natural History Departments of the British Museum.

difference in the proportions of this anterior group of teeth when compared in the two
animals, the remarkable fact is discovered that the Okapi has bifoliate lower canines
precisely resembling those of the Giraffe. This fact alone is sufficient to bring
Okapia—given its general Pecorine characters—into close association with Giraffa.
The bifoliate lower canine was not hitherto known in any other of the Pecora, or,

* The very much smaller relative size of the front teeth of the lower jaw ot Okapia than of Giraffa is shown
by a comparison of the drawings given here, viz. text-tigure 12, p. 293, showing the milk-dentition of this
region in Giraffa, with the permanent dentition of Okapia (Pl. XXXII. fig. 12), and the text-figure 9,
showing the permanent and the deciduous canines of Giraffa, compared with the permanent canines of Okapia,

of Samotherium, and of Sivatherium, drawn of natural size.

DR. E. RAY LANKESTER ON OKAPIA. 289

indeed, in any mammal at all, excepting Giraffa and its extinct allies Sumotherium and
Stivatheriwm (see text-fig. 9).

The bifoliate form of the canine of the Giraffide has no obvious explanation. The
existence of fissures in teeth of this shape and position finds a parallel in the curiously
fissured incisors of Galeopithecus. A closer point of contact is presented by the outer
lower incisors of Sus and Anchitherium, which have a distinct secondary lobe. The
canines of many Insectivora present a crown with two lobes, a feature which
Dr. Forsyth Major considers as pointing to the derivation of the canine from a
premolar. The great development of the second plate or “ folia” in the Giraffe’s canine
obviously serves the place of an additional tooth in increasing the amplitude of the
semicircular grip of the mouth. ‘There is no adjacent tooth on the diastemic margin
of the canine to interfere with expansion in that direction, and so the accessory growth
has free play. If the increase of the mouth-grip was the original motive of the
selection resulting in a bifoliate canine in Giraffide, it seems probable that Okapia,
with its very small mouth-grip and small incisors and canines, is not in respect of its
front teeth so primitive as Giraffa, where both incisors and canines are of so large a
size (proportionately to the other teeth) that the whole group or arch of front teeth
may be regarded as having attained a maximum only capable of increase by the
addition of a lobe to the outer member of the series (the canines) on each side.

The great size of the incisors and canines is especially striking in the young
Giraffe with milk-dentition and a lower jaw measuring only seven and a half inches
from the angle to the symphysis (see text-fig. 12, p. 293).

I have had drawings prepared, which are here reproduced (text-fig. 9, p. 288),
showing (A) a lateral view, natural size, of the canines and incisors of an adult
Giraffe, by the side of which are represented, also of the natural size, lateral views
(B) of the deciduous canine of the Giraffe, (C) of the permanent canine of Okapia,
(D) of the permanent canine of Samotherium, and (E) of the permanent canine of
Sivatherium. The extremely small size of the permanent canine of Okapia and the
large size of the deciduous canine of Giraffa are thus rendered very obvious.

In our lower jaw of Okapi (Pl. XXXII. fig. 12) the canine of the left side has a
bifoliate crown, whilst that of the right side has the crown broken and worn away.
They are obviously only milk-teeth, and on cutting into the jaw below that of the
right side we discovered, as we expected to do, the fully-developed bifoliate canine of
the permanent set, which is drawn in Pl. XXXII. figs. 4,5, and in the text-fig. 9,
p. 288. ‘This agreement in a point of minute but definite detail, found in Giraffide
and Okapia alone, has greater significance than any of the more general points of
resemblance presented by the skulls.

An important feature in the skull of Giraffa, which it is difficult to define, is one
which I can only speak of as “a tendency to tumescence” of the roofing-bones. This
feature is common to Okapia and Giraffu. It is well known that in the adult Girafte
272

onl _

290 DR. E, RAY LANKESTER ON OKAPIA.

the bones of the skull show a very considerable system of sinuses separating the upper
and under surfaces of certain regions of what are usually flat bones (see text-fig. 5, p. 286).
This “‘ tumescence” of cranial bones occurs in various Ungulata and other mammals ;
but it is not developed in other Pecora in the same regions and to the same extent as
it is in Okapia and Giraffa. In Okapia it is largely developed in the orbital region of
the frontal bone (text-fig. 10), and in the adjacent parietals in Giraffa (text-fig. 11,
p. 291). Also in both genera tumescence occurs in the expanded nasal region

Text-fig. 10.

View from above of the fronto-parictal region of the skull (larger of the two specimens) of the Okapi.

oce.h., angle of the occipital crest ; g.t.l., position of the lateral tumescence forming the paired parietal horns
of the Giraffe, absent here; of.l., the lateral frontal tumescence of the Okapi, absent in Giraffe; zy., the
zygomatic arch; po., posterior angle of the orbit; ao., anterior angle of the orbit; pl.v., prelacrymal
vacuity ; ofm., the slight median tumescence of the base of the nasals of the Okapi; sof., supraorbital
fossa ; sfp., the fronto-parietal suture.

For comparison with text-figure 11.

either in the nasals themselves or in the adjacent region of the frontals. The strong
development of the supraoccipital crest in both skulls (text-figs. 2 & 3, p. 284) is not
precisely of the same nature, for the thickened bone is not there excavated by sinuses.
I shall revert to this matter immediately, but must here point out the remarkable
form and aspect of the orbit of the Okapi, which is connected with the tumescence
of the bone which forms it. The orbit is rectangular, not circular as it is in

DR. E. RAY LANKESTER ON OKAPIA. ZO

Giraffa, and its margin is not formed by a thin upstanding rim of bony matter
as it is in Giraffa and nearly all Pecora, but is heavy, rounded, and thick. This
seems to me to be an archaic character—the sharp thin edge of the orbit being a
modern and truly Pecorine development. It is, nevertheless, found that the double
notch, or pair of notches, on the lacrymal border of the orbit have precisely the same
position and character in (what I am constrained to regard-as) the archaic orbit of

Okapia as in the modernized orbit of Giraffa.

Text-fig. 11.

View from above of the fronto-parietal region of the skull of a very young Giraffe. The parietal epiphyses
were already ossified, but separable, and are here removed.

oce.h., exostosis of the occipital crest, which in some adult Giraffes forms a second pair of “ horns ” (five-horned
Giraffe) ; gtl., the Giraffine lateral tumescence, seen here to originate in the parietal bone, which carries:
the conical epiphysis and forms the Giraffe’s paired “horns”; ot.l., the position of the Okapi’s lateral
tumescence of the frontal bone, absent in Giraffe; zy., zygomatic arch ; po., posterior angle of the orbit;
ao., anterior angle of the orbit; pl.v., prelacrymal vacuity; sof., supraorbital fossa; sfp., fronto-

parietal suture.

1V.—Tue AREAS OF TUMESCENCE OF THE GIRAFFINE SKULL AND THE NATURE AND
Origin oF tHE Horns oF PECORA,

In order to make an intelligent comparison of the skull of Okapia and Giraffa in
regard to the presence and absence of what are called “horns,” it is necessary to
discriminate between the varieties of horns presented by various groups of Pecora and
to accept one theory or another as to their origin and relationships.

The word “horn” is a comprehensive term of various and uncertain meaning. It

292 DR. E, RAY LANKESTER ON OKAPIA.

applies equally to the substance “ keratin,” of which many horns largely consist, and
to the antler of the Stag, which has no horn about it. The “‘horn” of the Rhinoceros
consists of a solid fibrous growth of keratin, resting on a slightly raised bony boss.
There is no “horn” of this structure known among the Pecora. ‘There are living
Pecora and there are allied living and extinct forms devoid of all trace of those growths
on the head which are called horns, whether of this or of that variety. Horns appear,
in proportion to their size and dominance, to be structures easily acquired and easily
lost, for they are often absent in the female whilst present in the male. They are
absent in both sexes in some domesticated races and present in others of the same
species; and, further, whilst commonly only a single pair are developed in Pecora, yet
a second pair may occur in a genus (Zetraceros) otherwise differing little from genera
with a single pair, and in domesticated races (Sheep) we have well-marked strains
without horns, with one pair, with two pairs, and even three pairs, and with large
and striking differences of shape and size.

The horns of the Pecora are essentially bony outgrowths, or “ ossicusps,” developing
on and from the roofing-bones of the skull. I definitely adopt this theory of their
nature and origin, and reject that which would regard them as originating ancestrally
either as horny plates or knobs of the epiderm, or as detached suhepidermal bony
plates like the carapace-elements of Glyptodon and Armadillo. The fact that in
Bovide the bony horn-core or ossicusp makes its appearance as a detached plate
of tissue which ossifies from an independent centre, and only fuses with the subjacent
bone during ossification, does not necessitate the conclusion that this was the
ancestral mode of origin of the horn.

The definite growth and selection of a pair or more “ ossicusps,” or exostoses, so as
to reach a size deserving the name of ‘ horns,” was probably preceded by a condition
of the skull in which “tumescence,” such as we see in Okapia and Giraffa, was a
general tendency. Rounded bosses were formed here or there, both paired and median.
They gave definite point to a blow when the head was used as a battering-ram, and
also by their sinus-structure made fracture a matter of small consequence. Variation
and selection would emphasize one or other pair of such “bosses,” or this or that
median boss, differently in different lines of descent. It is not necessary to suppose
that the paired horns of all Pecora are the lineal descendants of one and the same
pair of ‘* bosses” in ancestral forms. It is obvious enough that one of the pairs of
horns of Zetraceros has an origin independent of that of the other pair, and so too
with the smaller and larger pairs of horns of Sivathertum and the median and posterior
pair of Bramatheritum. ‘The tendency in primitive Ungulates to develop numerous
bosses on the skull, which are incipient horns, is seen in the extinct group represented
by the genus Dinoceras, with its anterior, median, and posterior pairs of horn-bosses.
‘The paired horns of Giraffa are shown by the young specimen drawn in text-fig. 12
to be distinctly related to a pair of bosses on the parietal bones and not to correspond

DR. E. RAY LANKESTER ON OKAPIA. 208

to the supraorbital frontal horns of Cervide and Bovide. On the other hand, the
paired supraorbital frontal tumescence of Okapia (text-fig. 2, p. 284), whilst not identical
with the paired tumescence of the parietal in Giraffa, does, it appears to me, corre-
spond in position and probably genetically with the supraorbital “ ossicusp ” developed

on the frontal bone of Samotherium and of the Bovide and Cervide.
From this statement, it will be evident that I regard the Giraffide as presenting a

more generalized ancestral condition of the horn-bosses than is found in any other

Text-fig. 12.

Lateral view of the skull and lower jaw of a very young Giraffe, measuring 30-8 centimetres from the

occiput to the anterior border of the preemaxilla, This is the same specimen as that represented in

fig. 11, and is preserved in the British Museum. ‘The drawing is five-twelfths of the natural size.

oce., occipital crest; gt.l., Giraffine conical tumescence of the parietal bone, above which is developed the
epiphysis (p.oss.); sfp., the fronto-parietal suture ; o¢./., position of the lateral tumescence of the Okapi,
absent here; gé.m., position of the median frontal tumescence of the Giraffe, which in this young
specimen is still entirely undeveloped; otm., position of the median tumescence of the Okapi’s skull

(basinasal) ; plv., preelacrymal vacuity ; can., bifoliate canine (deciduous dentition).

group of the Pecora. We have, indeed, in the Giraffide, taking into consideration its
various extinct members, an unspecialized condition of the tendency to horn-formation.
We know in them of either well-grown ossicusps or incipient osseous horn-bosses of
six locally different origins, viz.: (1) paired frontal supraorbital growths (Okapia,
Samotherium, small pair of Stvatherium); (2) paired parietal growths (Giraffa,
Stvatherium, Bramatherium); (3) paired occipital growths (large hinder pair of
Bramatherium, small pair of five-horned Giraffe); (4) median nasal growth (at the base

294 DR. BE. RAY LANKESTER ON OKAPIA.

of the nasals in Okapia); (5) median frontal growth (in Giraffa); and (6) median
parietal growth (in Z/elladotherium, text-fig. 4, p. 285, m.p.b.). It is not in every case
that these “ bosses” or “ tumescences” of the skull-wall have gone on to form well-
marked “ ossicusps,” still less have they always given rise to an ossicusp of such size
and importance that it has acquired an independently ossifying cap or epiphysis. ‘The
occipital exostoses of the five-horned Giraffe are well-marked knobs, but do not appear
to have independent ossification. On the other hand, the paired parietal and median
frontal horns of the Giraffe are prominent conical elevations of the outer plates of the
parietal and frontal bones respectively, separated by large air-sinuses from the deeper
plate and “ capped” (but not by any means solely constituted) by superficial cones of
bony matter, which ossify independently of the tumescence or boss of the cranial bone
on which they rest (see text-fig. 12, p. 293).

An interpretation of the separate ossification of these pieces and of the early
independence or separation of the ossicusps in the Bovide appears to find favour with
many zoologists, which I regard as erroneous. It is supposed that these bony pieces
have not originated from the skull, but are ancestrally independent dermal bony plates
which become fused to the skull. I think that this is an erroneous interpretation of
the facts. On the contrary, I think that just as the marked and outstanding processes
of other bones in the mammalian body (such as trochanters, vertebral apophyses, &c.)
acquire independent ossification, and appearing as “ epiphyses” ultimately fuse with
the bone of which they are in reality and origin only outgrowths (apophyses), so do
the ossicusps of the Pecorine horns acquire in many cases an independent formation,
which is related to their great size and importance, and is not a retention or exhibition
of ancestral independence. It is obvious that our whole view of the relations of the
“horns” of the Pecora to one another depends on the answer to this question—“ Can
a cusp-like outgrowth of a cranial bone, developed in continuity with that bone, be
the genetic equivalent of a cusp-like structure which has in late embryological stages
a detached appearance and an independent ossification, and becomes only after such a
period of separateness united to the subjacent cranial bone?” An investigation of the
embryological facts in the Bovide at a stage earlier than that described by Brandt’,

' See A. Brandt, “ Ueber Horner und Geweihe,” Festschrift Leuckarts, 1892. Recently Dr. J. Ulrich
Diirst has published a valnable essay, entitled, ‘‘ Versuch einer Entwickelungsgeschichte der Horner der
Cayicornia,” in the Festschrift zur Feier des 70. Geburtstages von Prof. Dr. Ad. Kreemar (Frauenfeld, 1902),
for the opportunity of seeing which I am indebted to Dr. Forsyth Major. Among the more important points
established by Diirst is the fact that the separated rudiment of the horn-core which appears in young Bovide
is not cartilage (as sometimes asserted), but, as one would have supposed, osteogenetic tissue.

It seems that we still do not possess a really thorough histological and embryological study of the ossicusp
or bone of the horn and antler of Pecora.

I yenture (as modifying somewhat what I have said in the body of this memoir) to put forward the
hypothesis that whilst the primitive element of the ossicusp is an outgrowth of the outer table of a cranial
bone, a secondary accessory bony element has been developed upon and in connection with this which has a

DR, H. RAY LANKESTER ON OKAPIA, 295

and a more minute histological study of the cellular origin of the tissues involved,
would probably give a decisive result in regard to this question. We have to note
that in the case of these cranial bony outgrowths we are dealing with tissues of very
special activity and variability. The annual detachment and breaking away of what is
admittedly a true outgrowth of the frontal bone in the Cervide and its regrowth, the
suppression of Pecorine horns altogether in races and individuals, as well as their
duplication, indicate that these bony growths cannot be in any case regarded as mere
processes of the bone of which they form part in the adult. That such was their
ancestral origin seems most probable; but quasi-independence and peculiar nutritional
relations have been subsequently acquired by them.

The theory that the Giraffine and Bovine horn-cores—as distinct from the Cervine
antler—have originated ancestrally from independent dermal bones, distinct from the
cranial roofing-bones, involves one of two suppositions, viz., either that the dermal

characteristic histological structure, and is referable to the same class of bony growths as those produced
pathologically in cases of rheumatic arthritis. This secondary element of the bony core of the Pecorine
horn is seen in a comparatively unmodified condition as the hollow cone-like caps or epiphyses of the horn-
cores of Giraffa. I suggest as probable that the caducous portion of the Cervine antler is genetically
identical with this epiphysial cap, whilst the base or ‘‘ Rosenstock” of the Cervine antler is identical with the
more or less protuberant boss or tumescence which is a direct outgrowth of the outer tabula of a cranial
bone in Giraffide. In vertical sections now before me of tke bony horns of full-grown Giraffes, it is evident
that this basal (and more primitive) element of the ossicusp is of considerable volume, and actually rises
up some four or five inches, so as to form the base and axis of the parietal horns, the epiphysial cap
having the form of a hollow cone which rests on and is fused with this deeper cone-like upgrowth. I find
myself in agreement with Dr. Diirst, who recognizes the existence of this truly frontal upgrowth in
Cavicornia as “ Hornstiel,” and identifies it “in gewisser Hinsicht ” with the “ Rosenstock ” of Cervidee.

The “ Hornstiel,” or horn-pedicle, or horn-boss, though small, is present in varying degree, according to
Dr. Diirst, in all Cavicornia. On the other hand, the “ Hornzapf,’ or horn-cone, of the Cavicornia (as
distinguished from the horn-boss) originates as a mass of osteogenetic tissue, separate from that which forms
the frontal bone; it constitutes by far the greater bulk of the bony structure of the horn. It seems to me
probable that the Cavicorn’s bony horn-cone is identical with the hollow conical bony epiphysis or cap of the
Giraffe’s horn, and, consequently, with the deciduous element of the Cervine antler. In Cavicornia the
primitive bony element of the horn, viz. the horn-boss, or Hornstiel, has been further reduced than it is in
the Giraffe, and its place is actually taken by the secondary accessory structure—the horn-cone or epiphysial
cap. A secondary growth, originally developed as an accessory to a primitive organ, has here (as happens in other
instances) acquired overwhelming vigour, and been substituted for the primitive organ, which consequently
dwindles and nearly disappears. The Giraffes, with their well-developed cranial horn-bosses and relatively
small epiphysial horn-caps (Hornzapffen) are intermediate between the Cavicorns and a primitive group
which had no epiphysial horn-caps, but only horn-bosses (Hornstiele). Our immature Okapia is actually
in the latter condition, and it seems (so far as adult specimens can allow one to judge) that the horn-cores
of the long-extinct Dinocerata also were true horn-bosses of the cranial bones and not epiphysial—that is
to say, not “ Hornzapffen,” or horn-caps.—E. R. L., April 30th, 1902. The actual mode of growth of the
frontal “‘ ossicusps” three inches in length, revealed in the adult Okapi recently received in Brussels, has yet
to be ascertained.—May 23rd, 1902.

VoL. XVI.—PART VI. No. 3.—Angust, 1902. D5;

296 DR. E. RAY LANKESTER ON OKAPIA.

bones in question are survivors of a general dermal cuirass, such as we see in
Armadillo, Glyptodon, and Mylodon, or that they are new formations. The absence in
other Ungulata of dermal bones of either class renders it more probable that the
“separateness” of the horn-cores of Giraffa, and in a less degree of Bovidee, is an
acquired feature comparable to (if not identical in detail with) the ‘ separateness” of
trochanteric and other epiphyses of bones in other parts of the skeleton. It is worth
noting in this connection that in skulls of old male Giraffes the periosteum at

’

various points—e. y., an additional median site and supraorbital sites—becomes active
and deposits rough growths of bones (exostoses), resembling those seen in old
rheumatic limb-bones of Man.

The horns of Pecora, in reference to their complete structure and history, may be

grouped in four categories :—

1. The Vellericorns of the living Giraffide, with soft hairy integument covering the
ossicusp: the ossicusp either a cone-like upgrowth of the outer table of a
cranial bone with an accessory separately-ossifying ‘‘ cap ” or epiphysis or else a
simple exostosis (occipital horns of 5-horned Giraffe).

. The Cavicorns of Bovide, with a horny theca: the ossicusp before ossification
appearing as a knob of soft tissue separated from the subjacent cranial roof,

bo

but subsequently fused to it.
. The Caducithecal Cavicorns of Antilocapra, with a horny theca which is shed and

3

replaced annually.

4, The Antlers of Cervide, direct outgrowths of the outer table of the frontal bones,
clothed in an early stage with soft hairy integument, as in the vellericorns of
Giraffide, but losing this integument and exposing the distal portion of the
bony ossicusp, which dies, is shed, and regrown annually, whilst the basal
portion (Rosenstock) remains in perpetuity as part of the frontal bone,

The cavicorns of the Bovide can be readily derived hypothetically from frontal
vellericorns in such a position as the ossicusps of the Giraffid Samotheriwn (= Paleo-
tragus). The development of a permanent horny theca on the integument covering
the ossicusp necessitates, if the horn so formed is to increase in size, that it shall grow
only from the base: that is to say, it cannot develop branches which shall grow in
proportion with the rest of the horn. Hence the permanent cavicorn is unbranched.

The vellericorn covered by soft growing integument meets of course with no obstacle
in assuming a branching form in the course of growth, and perhaps the palmate horns
of Sivatherium were vellericcrns. The form of the posterior horn-cores of Brama-
therium is, however, so much like that of a bovine horn-core that it seems probable
that these extinct Giraffide had developed a horny theca upon the integument of their
horns. In that case the palmate horns of Sivatherium not improbably had also a theca
which they must have shed from time to time during growth.

DR. E. RAY LANKESTER ON OKAPIA. 297

The caducithecal cavicorn of Antilocapra is, it seems, the sole modern example of
the combination of horny theca with branched or prong-bearing form. If we assume
that, starting from conditions more or less closely similar to those exhibited by the
vellericorns of Giraffa, there was, so to speak, a demand for a large branched prong-
bearing horn, there would be two alternative modes of meeting the demand. The
integument might be left unprotected and soft on the growing antler, in which case it
would tend to be seriously damaged and torn by blows, or it might be protected by a
theca, periodically shed and renewed. A periodicity in the nutrition of the horn-
structures would be established in the latter case. In the former case the exposure of
the bony mesoblastic tissues by abrasion of the integument would tend to necrosis of
the bone and serious danger to the animal. It would thus be an advantage that the
exposed dead bone of the antler should be shed and a new formation take place at
intervals. ‘The establishment of a relation between this and the nutritional activity of
the recurring annual process of sexual ripening is not an improbable thing. ‘The
periodicity of the horn-shedding of the caducithecal forms and that of the antler-
shedding forms may well have had a common origin.

The antlers of Cervide seem thus to be an outcome of the simple short vellericorns
still retained by the Giraffe, and the three structures—viz. unbranched Cavicorns,
Caducithecal Prong-horns, and naked regenerative Antlers—are three distinct lines of
development of Pecorine horns of increased strength, amplitude, and resistance, from
conditions present in ancestral Giraffide. These varieties of horn-structure were
probably more or less completely differentiated within that group, or in a more
generalized set of forms antecedent to it.

Whilst thus referring the various forms and structures of Pecorine horns to primitive
conditions retained by Giraffide, I do not overlook the fact that in regard to other
important structures the Giraflide do not exhibit archaic features. ‘Ihe great length
of the diastema in the dental series and the complete absence of upper canines are
points in which Giraffide are not primitive, as also is the total suppression of the
pettitoes. In possessing often well-developed, even extremely large, canines the
Cervide are more primitive than the Giraffide ; and both Cervide and most Bovidee, in
the frequent presence of well-developed extra digits, retain an ancestral feature lost
by Giraffide. There is, however, ample ground for supposing that in the differentiation
of lines of descent from the primitive Pecora one group may have retained one set of
characters in a primitive condition and another group another set.

I propose now briefly to revert to the Okapi’s skull and its “bosses” or
“tumescences.” It is, of course, possible, as our larger specimen is only two-thirds
grown, that a separate “ossicusp” was destined to develop over each of the supra-
orbital bosses (o¢/. in text-fig. 2, p. 284). There does not appear to have been any
rudiment of such a structure in the dried skin of the head as removed by the

2u2

298 DR. BE. RAY LANKESTER ON OKAPIA.

natives and received in this country’. But there is evidence that the integument was
very closely applied to the bone of the supraorbital bosses and that there was a specially
vascular condition of the periosteum in the centre of the boss. A figure (text-fig. 15)
of this appearance is here given. The hair on the integument is arranged so as to
converge on the centre of the boss, and there isa distinct upstanding of the hairs around
it and a bare spot at the actual centre (text-fig. 14, p.299,@andc). ‘The arrangement

Text-fig. 13.

Drawing (natural size) of a portion of the skull of the Okapi (larger specimen), to show the surface of the
right frontal boss. The surface of the bone shows numerous grooves occupied by blood-vessels, indicating
that the periosteum was here in close vascular continuity with the subcutaneous connective tissue.

[The peculiar vascular condition of the surface of the bone at the supraorbital tumescence now receives its

explanation in the later growth here of the bony tissue to form the large conical ossicusp.—May 27th,
1902.)

of the hair over the two orbital bosses (a and c) and above the nasal tumescence (/),
as shown diagrammatically in text-figure 14, p. 299, is very remarkable.
It is improbable that at this age and size our Okapi, if a male, had yet to develop

‘The existence of such a rudiment was at first supposed by me to exist, and a notice by me in an
illustrated weekly paper is quoted by Dr. Diirst (loc. cit.) to that effect. I found, however, on cutting open
the skin of the head after it had been received from the taxidermist that there were no thickenings of the
integument over the frontal bosses, but that the taxidermist had taken the liberty of inserting a small plug
of cotton-wool over each frontal boss, so as to give a strongly marked prominence to the integument in this
position. E. R. L., April 80th, 1902. It now appears (May 23rd) that my original supposition was probably
correct, since the Brussels skull of an adult Okapi shows ossicusps three inches in length, though their mode
of growth is not yet ascertained.

DR. E. RAY LANKESTER ON OKAPIA. 799

Text-fig. 14.
Jil "
7) iM A
— AANTMIWNS
GAMA
ee TIMI Sm
(1/1) \\ See
SSS My I <SSS ee
SSI EEEN A NWI ER SS SZ
Sa ae SSS
SZ NAN Hi oS
SSE il AKG INS SSF
h / Ii | HNN NS LLL A
VN = ee
YPN 2) We
ANNO NN
AYN
Ay 2 ey eA
SZ | Wy MU Lh
Ay iy
LAW EO
Zh eA
S\N
NWS HAART
REZ HII
HN WC RQIARS
ZAM
DNA 2s
gy ZA bs
== S= Vf ZEEE

We
iii i / My, Wi

Diagram to show the arrangement of the hair upon the frontal and basinasal regions of the Okapi’s head.
The free ends of the hairs are represented by the points of the arrows. aand ¢ are natural bald spots
overlying the apices of the boss or tumescence of the right and left frontal bones. 6 is a bare spot,
probably due to abrasion. The tuft of hair below ¢ is well-marked, but is absent on the opposite side
of the head. The whorl marked d corresponds in position with the slightly tumescent base of the
nasal bones. The unlettered whorl, near the middle of the figure, possibly owes its position to the
left of the mid-line to unequal stretching of the skin by the taxidermist. The study of the hair-
whorls on the head of various Mammalia may yield important data for systematists, but has not yet been
methodically carried out.

300 DR. E. RAY LANKESTER ON OKAPIA.

any separate horn-cap or epiphysis, but it may well be that the supraorbital boss
becomes more accentuated in the adult or old male.

On the other hand, supposing our older specimen to be a female, it is possible that
the male has much more pronounced horns. It is impossible to decide whether our
large specimen is male or female, and we must await the arrival of further specimens
of the Okapi for information on the subject.

The bases of the nasal bones are slightly thickened or swollen in the Okapi (as
shown in text-fig. 2, p. 284, ofm.,and in Plates XXXI. & XXXII). This swelling
is thus in front of the region carrying the median boss of the Giraffe’s skull, just as the
paired lateral swellings are anterior to those of the Giraffe. In Helladotherium there
are no lateral ‘ bosses,” but a median boss is present which is further back even than
in the Giraffe, and is distinctly parietal in position (text-fig. 4, p. 285, m.p.b.). A
spiral arrangement of the hair of the Okapi’s face corresponds in position to this slight
thickening of the nasal bones (see text-fig. 14, p. 299, d).

There are those who would interpret the apparently hornless condition of Hellado-
therium and Okapia as due to a degeneration and loss of horns, present and well
developed in ancestors of these genera. On the other hand, it is possible to regard
these two forms (if actually proved to be hornless) as being in a primitive condition,
having developed the bosses or tumescences which are the first step in the history
of horns, but never having got any further. It does not seem to me possible to
decide between these two theoretical views; but I am inclined, on account of the
absence of a deflection of the basicranial axis from the horizontal of the basifacial
axis or palatine, to infer that neither Okapia or its ancestors ever possessed large frontal
horns—not even horns so large as the parietal horns of Giraffa. The possession and
use of such horns (as distinguished from laterally-spread antlers) seems to involve the
mechanical necessity of a deflected cranial floor. Even Giraffa exhibits such a
deflection in small degree (see text-fig. 5, p. 286).

V.—CHARACTERS PRESENTED BY THE SKIN OF THE ORAPI.

The skin of the Okapi, when received in London, was in very good condition. The
paired ungual phalanges were still attached to the skin, but the horny hoofs had
heen lost. The skin was softened and mounted for the Natural History Museum by
Mr. Rowland Ward. It must be remembered that no white man has as yet seen, or
at any rate given any account of, a living Okapi, nor even of the body of one freshly
killed. Nor have we received the skeleton of any part except the skull and hoofs.
Accordingly the proportions assigned to the various parts of the animal and the
carriage of its head and neck are, to a certain extent, conjectural and determined by
the proportions of the skin only, as thus received. The animal, as mounted, is shown
in the two drawings given in Plate XXX. with the natural colours.

DR. E, RAY LANKESTER ON OKAPIA. 301

The chief point of doubt in the result obtained by Mr. Rowland Ward is as to the
carriage of the head and neck. He has, in agreement with me, made the neck
continue the line of the back as it does in the Giraffe and some of the Antelopes.
It has been suggested that the neck should rise nearly vertically from the shoulders
and form more of an arch, as it does in some Ungulates; but we have no information
as yet to guide us in the matter. It is quite certain that all the old drawings and
mountings of the Giraffe, which represented that animal’s neck as rising vertically
with a graceful curve from the shoulders, are erroneous. The Giraffe’s neck is
habitually carried in a line which is a continuation of the rising line of the back
from haunches to withers. The neck inclines forward, with the head projecting far
in front of the fore legs, whether the Giraffe is at rest or in movement. It is only
when the Giraffe is reaching with the mouth at some object higher than the head that
the neck assumes a vertical position.

The following are the measurements of the skin of the Okapi as mounted :—

feet. inches.

From occiput to root of tail. . . . . . . . 1860mm. = 6 2
IRON Oey Wo uM 5 3 5 6 6 5 6 6 5 Ain, = I g)
From occiput to withers (length of neck) . . . 870mm. = 2 11
From withers to root of tail. . . ... . . . 990mm. = 8 3
Eleie hia tawathers) es sie) amen eee 1530 mm. = 5 1
Height at rump (through head of femur) . . . 13870mm, = 4 7
Length of auricle of ear from constricted base to

Doo ouuoloyaG oO. pS bo el eot > ee aon, SO 9
Breadthyofauriclerofjear, Ya. 94 9 42. ont 2 142imme — 0 54

The most noticeable features in these proportions are, first, the much greater height
of the fore-quarters than the hind-quarters, the great length of the neck, the great
length of theears. In the first two points mentioned the Okapi resembles the Giratfe,
which, however, has the same features in an exaggerated degree. In the proportionate
length of its ears the Okapi greatly exceeds the Giraffe.

The hairy coat of the Okapi resembles that of the Giraffe and Zebra in length and
quality.

The colour of the animal is shown in the figures accompanying this memoir. The
hair on the body and neck and the top of the head from the occiput to the nostrils
and the ears is of a rich reddish brown, whilst that on the side of the face is a creamy
white.

The rump and hind legs, as far as the tarsal joint, are striped transversely with
alternate bands of dark chocolate (almost black) and brownish-white hair. A curious
feature is the reddish-brown colouring of the narrower parts of the white stripes,
which gives the impression that the colour has “run” from the darker stripes. The

302 DR. E. RAY LANKESTER ON OKAPIA.

pattern of the stripes on both the hind and fore limbs is difficult to describe, and
can best be judged of by the figure given in Plate XXX. and by the woodcut of
the bandoliers (text-fig. 1, p. 281) cut from another individual. ‘There appears to be a
small range of individual variability in the exact proportions of the dark and light
stripes.

The true foot—that is to say, the part of the leg extending from the calcaneum to
the hoof inclusive—is white with a dark girdle encircling the first phalanx and leaving
a white circle between itself and the hoof, which was seen by one of Sir H. Johnston’s
officials before it was lost, and reported to be blue-black in colour.

The upper region of the fore limb is of the same colour as the trunk; black and
white striping is not developed upon it until we come to the region of the forearm or
radio-ulnar region. This is encircled by a few narrow and two incomplete broad bands
of black hair separated by bands of white. The carpo-metacarpal region is peculiarly
marked: an oblong disc of white hairs is found on the carpus encircled by black.
The black hairs extend as a thick band round the back of the carpus, the white disc
having a nearly median frontal position. From the black ring extends downwards over
the front of the metacarpal region a thick black band lying a little to the outer side
of the mid-line. This black band joins a ring of black hair which encircles the
phalangeal region as in the hind foot, the rest of the hair being creamy white. The
appearance of this upper upright ring, bar, and lower transverse ring joined to form
one piece is very remarkable and calls to mind the shape of a leg-iron or shackle
such as is fastened to the legs of convicts. It probably has some significance in
producing illusion when seen by the enemies of the Okapi; but it is difficult to
imagine its exact effect. I have not been able to find a closely similar marking
in any other animal except in certain goats—especially the Wild Goat of Asia
Minor (Capra cgagrus). The corresponding region is very similarly marked in
specimens of that animal preserved in the Natural History Museum. ‘The one-
sided position of the vertical bar is very striking and tends to give an unreal and
distorted appearance to the leg.

VI.— CHARACTERS OF THE GENUS OxaPr4 AND OF THE SPECIES O. JOHNSTONT.

At the Meeting of this Society on June 18th, 1901, I established the genus Okapia
for the reception of the Okapi. A brief account of the skin and skulls was published
by me in the Proc. Zool. Soc. 1901, vol. ii. p. 280. I now amend the characterization
of the genus in some important respects !.

The ‘“* Pecora” are ruminant Artiodactyle Ungulates with a cotyledonary placenta
and are divisible into the Cervide, Giraffide, Antilocapride, and Bovide.

* May 27th, 1902.—So as to take cognizance of the fact as to the existence of bony frontal horns in the
adult, revealed by the specimen received in Brussels a month ago. See Appendix, p, 304.

DR. E. RAY LANKESTER ON OKAPIA. 303

The characters of the Giraffide are as follows:—‘ Pecora with no canines in the
upper jaw, with bifoliate crown to the canines of the lower jaw; with complete
suppression of the second and fifth digits of both fore and hind feet; without lacrymal
fossa; with horn-bosses or ossicusps of variable position (frontal, parietal, occipital, and
nasal) not necessarily restricted to a single pair, often one or all rudimentary. In the
living genus Giraffa the horns are vellericorns, but probably in some extinct genera
they developed a horny theca (cavicorns), and in others may have been exposed as
naked antlers.” :

Using the foregoing definitions of the groups Pecora and Giraffide, the genus Okapia
may be characterized as follows :—

“ GIRAFFIDZ WITH A PAIR OF SUPRAORBITAL FRONTAL HORN-BOSSES, BEARING IN THE
ADULT WELL-MARKED CONICAL BONY HORNS OR OSSICUSPS. ‘THE HORNS COVERED (except
at the tip) BY HAIRY INTEGUMENT, NOT BY A KERATOSE THECA. A MEDIAN TUMESCENCE OF
THE NASAL BONES, BUT NO MEDIAN HORN (OSSICUSP). PLANE OF THE BASICRANIAL AXIS AND
THE BASIFACIAL AXIS APPROXIMATELY PARALLEL. ARCH FORMED BY THE FRONT TEETH OF
LOWER JAW SMALL AND NARROW; INDIVIDUAL INCISORS AND CANINES RELATIVELY VERY SMALL.
OUTER EARS LARGE.”

N.B.—Okapia is thus contrasted with Giraffa, in which the paired horn-bosses are
parietal instead of frontal, and in which also a median frontal tumescence and bony cap
develop; and with Helladotherium, in which there are no paired horn-bosses. It is
further contrasted with Giraffa (and all other Giraffide) in respect of the small size
of its mandibular arch of incisors and canines. ‘This is the only point in which it
differs from Samotherium (Palwotragus), unless further study of the nature and
development of the frontal horns should establish a difference between it and this
genus. It differs from Giraffa in the great size of its external ears.

The genus Okapia contains a single species, O. johnstoni—the Equus johnstoni of
Sclater (P. Z. S. 1901, vol. i. p. 50). The species was originally based upon pieces of
the striped skin from the hind limbs, and may be defined as follows :—

O. sounstoni (Sclater). Okapia with the hind limbs (rump, femoral and tibial region)
striped with alternate bands of blackish brown and white; tarso-metatarsal region
white: fore limbs marked with a shackle-pattern—black on a white ground—on the
carpus and metatarsus, radial region transversely striped. Body, neck, rump, and
upper part of fore limbs a uniform rich reddish brown; side of the face white, top
of the head reddish brown. ‘Tail brown, tapering, with subterminal tuft of long hair.

Mane absent.

bo
bs

VOL. XVI.—PART VI. No. 4.—August, 1902.

304 DR. E. RAY LANKESTER ON OKAPIA.

VIL—APPENDIX. (May 27th, 1902.)

Since this memoir was ready for press (actually in second revise) the Museum of the
Independent State of the Congo received (at the beginning of May) in Brussels, through
the agents of the State stationed on the Aruwimi, near Fort Mbeni, the place where
Sir Harry Johnston’s specimen was obtained, a skin of an adult female Okapi, and
a nearly complete skeleton of an adult male. The actual locality from which the
specimens come is stated to be Mawambi. Dr. Forsyth Major has been entrusted by
the authorities of the Congo Independent State with the study and description of these

Text-fig. 15.

Skull of adult male Okapi. Outline drawn from the skull of the adult male belonging to the
Museum of the Independent State of the Congo.

The drawing represented the left side, but has been reversed for comparison with the figures in the present
memoir. Note the large ossicusps ; the divided prelacrymal fossa; the molars, of which the first upper
premolar is lost; and the defective canines and incisors.

important specimens, and has been to Brussels to examine the material. ‘The skull
and various bones of the adult male have been sent to him in London since his return,
for further examination. I owe an opportunity of examining the skull to the
courtesy of Dr. Forsyth Major, who is carrying on his work on the subject here, in
the Natural History Museum.

A full account of the new specimens will be published by Dr. Forsyth Major in the
Memoirs of the Museum of the Congo State. It is not of course to be expected that I
should here anticipate the interesting results which will be given in Dr. Forsyth Major's
full account of the new specimens, but I am able to state a few of the more striking

DR. E. RAY LANKESTER ON OKAPIA. 305

facts, and to include in the present memoir an outline sketch, prepared under his
direction (text-fig. 15, p. 504), of the skull of the adult male.

The specimens received in Brussels in May 1902 are the skin of an adult female
and the skull and most of the bones of an adult male. The male skull bears (as shown
in text-fig. 15) bony horn-cores of a conical shape, about three inches in length.
They are much deflected so as to point backwards. In the skin of the female
(Dr. Forsyth Major states) there are (although the skull is wanting) bony horn-cores
of about two and a half inches in length. The dentition of the male skull and of the
lower jaw belonging to it are well preserved, and leave no doubt as to the adult
character of the specimen. It is remarkable that, whilst differing greatly in age from
our larger specimen, and having developed the large and powerful bony ossicusps
which are only represented by the frontal tumescences of our skull, yet the new adult
male skull is very little larger than our larger specimen. ‘The measurements of the
two are as follows :—

Sir Harry Johnston’s Male adult skull,

larger specimen. Brussels.
From occipital crest to front margin of nasals . . . 375 mm, 077 mm.
Maximum width (at zygomatic arch) . . . . . . 182 mm. 178°5 mm.

The margin of the orbit is sharper in the Brussels skull than in ours. There is no
indication of an “ ossicusp” in connection with the swollen base of the nasals. The
skull is in very fine and perfect condition, and will afford data for complete comparison
of the base of the skull and the adult dentition with that of the Giraffe and of
Samotherium. ‘The periotic capsule and tympanic bulla are of much larger size
relatively than in Giraffa. This agrees with the relatively large size of the external
ear or auricle in Okapia.

The important and striking feature in the Brussels skull is the presence of supra-
frontal ossicusps. ‘The doubts expressed in my memoir in the preceding pages are
thus resolved. ‘Though I had definitely recognized the possibility of the development
of such ossicusps in older specimens than ours, yet it must be admitted that I was
inclined rather to favour the supposition that outgrowths of so large and well-
developed a character as those which are now shown to exist would not be found in
the adult Okapi. Their presence tends to bring Okapia into very close agreement with
Samotherium. It is remarkable, in view of what is known as to the development of
the ossicusps on the parietals of Giraffa, that Okapia should attain to practically adult
size without having its ossicusps more strongly developed than they are in Sir Harry
Johnston’s larger specimen. I can hardly doubt now that some osteogenetic, if not
actually osseous, cone was present between the skin and the supraorbital tumescence
of the frontal in that specimen and was lost in cleaning the skin.

We do not yet know the facts as to the mode of development of the horns of the

2x 2

506 DR. E. RAY LANKESTER ON OKAPIA.

Okapi. The fine bony cones, three inches long, which have made their appearance in
the Brussels skull (see text-fig. 15, p. 304) show no suture at their base, or any indication
of origin as distinct cap-like structures. For all that one can see, they may be direct
outgrowths of the frontal bone itself. Curiously enough, the point and posterior
margin of the bony cusp is polished as though it had protruded through the skin like
a cervine antler. The point is separated by a suture from the rest of the ossicusp,
forming a small terminal cap of bone a third of an inch in depth. ‘This curious
structure, as well as a possible second suture a little lower down the ossicusp,
was pointed out to me by Dr. Forsyth Major. These appearances will be figured
and discussed in that gentleman’s memoir on the Brussels specimens. It is clear
that we must wait for specimens of intermediate growth in order to form any
conclusions as to the mode of growth of the Okapi’s ossicusps, It seems not
improbable that when we have those facts, important light will be thrown on the
relationships inter se of the various cranial ossicusps of Giraffide, Cervicornia, and
Cavicornia,

It is perhaps worth while calling special attention to the fact that Sir Harry John-
ston’s larger skull of Okapia is very nearly as long as the adult male skull recently
acquired by the Congo State Museum ; there is only two millimetres difference in the
length from the occiput to the end of the nasal bones. Sir Harry’s specimen is actually
broader by three and a half millimetres than the Brussels skull. And yet Sir Harry’s
specimen has no ossicusps and shows the fronto-parietal suture clearly, whilst the
Brussels specimen has bony ossicusps three inches long and absolutely continuous
with the frontal bone, whilst the fronto-parietal suture is obliterated. Perhaps the
difference of form and the late appearance of the ossicusps in our larger specimen as
compared with the Brussels skull are due to the fact that our specimen is a female,
whilst (according to direct testimony of the senders) the Brussels skull is that of a
male. We have yet to hear further details as to the bony horn-cores reported by
Dr. Forsyth Major as embedded in the skin of the head of the second Brussels
specimen, which is known to be that of a female, and of which neither skeleton nor
skull accompany the skin. These detached horn-cores of the female are stated by
Dr. Forsyth Major to be two and a half inches long.

A further point to which I may draw attention is that there is considerable want of
symmetry in the Brussels skull, in so far as the size of the bony horn-cores is concerned.
One is distinctly larger than the other. Now it is a curious fact that the skin of the
head of our Okapi shows, as I have pointed out (text-fig. 14, p. 299), a marked
asymmetry in the hair-whorls of the frontal region. Until the hair-whorls of Mam-
malia have been more closely studied, it will not be possible to say what amount of
significance should be assigned to this asymmetry. But it seems to me to offer an
interesting field for enquiry.

DR. EB. RAY LANKESTER ON OKAPIA. 307

As bearing on the question of the relative ages of the Brussels skull and our large
hornless specimen, I may say that whilst the Brussels skull shows the molars and
premolars in a worn condition and the incisors and canines much used, our larger skull
has the following dental formula :—

Right side: i. 0 0 ’ 2 perm. (not cut), 1 dec. ; 3 perm, (in use)
Ste Sine 3 perm.” —" 1 dec.’ ta 3 dec. (worn) De perm. (in use)
Left side: i. 2°, c. _°_, pm. and m. broken away above, same as right side below.
3 perm. 1 dec.

Our smaller skull has no lower jaw and shows three milk premolars and one per-
manent molar only, on each side of the upper jaw.

In conclusion, I may say that the adult dentition resembles, so far as the molars and
premolars are concerned, very closely indeed that of Giraffa, whilst no new light is
thrown by the new specimen on the permanent canines and incisors of which the larger
of Sir Harry Johnston’s specimens gave us full knowledge.

eat

Sl
2

310 DR. E. RAY LANKESTER ON OKAPIA.

PLATE XXX.

Two views of Okapia johnstoni, drawn from the skin obtained by Sir Harry
Johnston as mounted in the Natural History Museum.

The specimen is not adult, but very nearly full-grown. The horns (recently
discovered in specimens obtained by the Independent State of the Congo)

are not yet developed. It is not known whether the specimen here
figured is male or female.

(INOLSNHOLP VIdVMO) 1dVMO HHL

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TAD the IAN 7V0°P2 Le "Lo

TOOL

VOL. XVI.—PART VI. No. 5.— August, 1902.

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DR. E. RAY LANKESTER ON OKAPIA.

PLATE XXXI.

View from above of the smaller of the two skulls (that which does not belong
to the skin). Drawn of about half the natural size. The actual measurement
of the specimen is :—from the occipital margin to the free end of the nasals,
312 mm.; from the occipital margin to the free end of the premaxillaries,
575 mm.—Reference letters: a, supraorbital tumescence of the frontal bone
(site of the future ossicusp or bony horn-core); 0, the right premaxillary
bone ; ¢, the prelacrymal vacuity.

View from above of the larger of the two skulls (that which belongs to the
skin and lower jaw). Drawn of about half the natural size. The actual
measurement of the specimen is:—from the occipital margin to the free end
of the nasals, 375 mm.—Reference letters: a, supraorbital tumescence of the
frontal bone (site of the future ossicusp or bony horn-core); 6, the left
premaxillary, absent in the specimen and drawn here of a lighter tint; c, the
prelacrymal vacuity; d, the median tumescence at the base of the nasal
bones (see in this connection the profile view of the smaller skull in
Plate XXXII.); ¢, the parietal bones; the fronto-parietal suture is well-
marked, but the interparietal suture is already obliterated in the smaller skull
as well as in this; f, the emarginated occipital ridge.

. The anterior group of teeth of the lower jaw belonging to the larger skull.

The teeth are drawn as seen from above, and of the natural size. From the
outer margin of the right canine to the outer margin of the left the measure-
ment is 41 mm. ‘The six incisors are those of the permanent set ; the canines
are the deciduous ones, not yet replaced.—Reference letters: del, left
deciduous canine; der, right deciduous canine; pi, pi, the six permanent
incisors.

The right permanent canine, obtained by cutting into the bone below the
deciduous canine; inner (adoral) face. One-tenth larger than natural size.
Outer (aboral) face of the same tooth as that drawn in fig. 4.

The left deciduous canine, drawn so as to show the outer (aboral) surface. One-
tenth larger than natural size.

. Crown of anterior deciduous molar of the right lower series (marked dm!) seen

from above. Natural size.

Crown of the second (counting the more anterior as the first) deciduous molar
of the right lower series (marked dm?) seen from above. Natural size.

Crown of the third deciduous molar of the right lower series (marked dm)
seen from above. Natural size.

. 10. The crowns of the three non-successional or true molars of the right lower

series seen from above: m1, anterior true molar; m*, second true molar; m’,
third true molar.

Trans Loot Joo Vol. KV Bb XX.

EG 10)

=
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E OKAPI (OKAPIA JOHNSTONT)

1, Grbnvold, del,

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SUA raailed

ieee ae

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wie}

Big

Fig.

sell

DR. E. RAY LANKESTER ON OKAPIA.

PLATE XXXII.

View of the right side of the smaller skull drawn in fig. 1, Plate XXXI.
‘The drawing is reduced to three-eighths of the natural size.—Reference letters :
a, the supraorbital tumescence of the frontal bone (site of the future ossicusp
or bony horn-core); ¢c, the prelacrymal vacitity. ‘The tumescence of the base
of the nasal bones is well seen in profile.

_ View of the right side and right ramus of the lower jaw of the larger of the

two skulls, viz., that drawn in Plate XXXI. fig. 2. The drawing is reduced
to three-eighths of the natural size. The basal part of the cranium is broken
away in this as in the smaller skull, and the maxillary teeth of the right side
only are preserved.—Reference letters: a, the supraorbital tumescence of the
frontal bone; 6, the absent premaxillary bone, sketched in lightly of pro-
portionate size from the same region of the smaller skull; ce, the prelacrymal
vacuity ; d, the median tumescence of the base of the nasal bones; e, the
parietal bone ; f, the occipital crest; y, the three anterior incisors and canine
of the lower jaw. ‘The extremely small relative size of this group of teeth, as
compared with the dimensions they exhibit in the Giraffe (and all other
Pecora), should be realized by comparing this figure with the text-figure 12,
representing the skull and lower jaw of a very young Giraffe, reduced to very
nearly the same scale, that of the young Giraffe being one-ninth larger in
scale.

. The molar teeth of the right upper series of the larger of Sir Harry Johnston’s

two skulls of Okapi, showing the crowns. The third true molar is breken and
therefore not figured.—dm!, the anterior miik-molar, not yet shed; pm, the
second premolar, exposed by the shedding of the second deciduous molar, but
not yet “cut”; pm*, the third premolar, exposed by the shedding of the third
deciduous molar, but not yet cut; m1, anterior or first true molar (cut);
m*, second true molar (cut).

Fig. 14. The molar teeth of the right upper series of the smaller skull of the Okapi.—

dm}, dm?, dm*, the three deciduous molars ; m!, the first true molar. The second
true molar had been cut, but is not preserved in the specimen; the third true
molar had not yet been cut.’

THE OKAPI (OKAPIA JOHNSTON!)

H. Gronvold, del.

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CONTENTS.

VII. On Okapia, a new Genus of Giraffidee, from Central Africa, By EH. Ray LANKESTER,
MA. LL.D., F.RS., F.ZS., Director of the Natural History Departments of
the British Museum, Correspondent of the Institute of France. (Plates XXX.—
p00 Gh en een a Ror ce oe) Suhr ce ate

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VILL. On the Structure of the Larval Polypterus.
By J. 8. Bupertr, W.A., PZ.

Received and read December 17, 1901.

[Puates X XXIIT.-XXXV.]

Contents.
Page
Teen GroduUctiomy .yseeatacecearsycaseessneas Ger eevae tees Ee ee Oe ae 315
Hike MaterialvandsMethodssaear ner ences cient 317
WU They Skeletom’ siensie essnsctctcicve: sv seneiet ovencusle archaeon outeneuerstane 319
IN, Whalmogeritiall Onsen) coosnsacousndecaecnoods0bnan0008 330
Went @ oni clust omic. ctsccresuszenstencwos suai tesrstai or crreoeterene rater renee iene 338

I.—Intropuction.

ALTHOUGH Polypterus is undoubtedly one of the most interesting forms of recent
Vertebrata, in that it is one of the two survivors of a very ancient group of fishes
which existed in an abundance of forms in the Devonian era, its anatomy was until
recently only imperfectly known; while nothing was recorded of its life-history and
development, the knowiedge of which might be expected to throw much light on the
relationships of the great groups of the lower Vertebrata. ‘The study of the structure
of a very young larval Polypterus which I had obtained seemed to me therefore of
considerable interest.

The attempt to arrange recent groups of animals in a linear series or even in the
form of a genealogical tree appears to me to be misleading. ‘The affinities of recent
groups should rather be represented by a chart of an archipelago of groups, the
remains of a submerged continent, the configuration of which the study of paleontology
alone can reveal.

The significance of the observations recorded in the following pages appears to me
to be that Polypterus must be regarded as having affinities with several of the great
groups of fishes on the one hand, and also with the amphibians on the other hand.
From this I am led to conclude not that the modern Crossopterygians form a connecting-
link in a phylogenetic sense, but rather that they form a central group amongst recent
forms having affinities with, and so connecting together, a number of the great groups
of Vertebrates ; for, as will be seen, in parts of their structure they show undoubted
affinities with the Teleostei and Ganoidei, while in other respects their structure reveals
affinities with the Elasmobranchii ; in addition, however, they show affinities in a third
direction, namely with the Stegocephali and through them to the Amphibia. That
there is any very close connection between the living Crossopterygians and the living
Dipnoi does not appear to be the case.

VOL. XVI.—PART vil. No. 1.—October, 1902. 22

316 MR. J. 8S. BUDGETT ON THE STRUCTURE

Some authors have attempted to show that the Amphibia may have been directly
derived from some such forms as the recent Crossopterygii, others derive them from
the Dipnoi: with both these views I venture to disagree. ‘The Devonian Crosso-
pterygii no doubt merged into the Devonian Dipnoi, and it was from forms probably
intermediate between the Crossopterygii and the Dipnoi that the ancestral Amphibians
originated. In these times likewise the Crossopterygli merged into the Elasmo-
branchii and thirdly into the Ganoidei, and it was from forms probably intermediate
between the Crossopterygii and the Ganoidei that the Teleostet originated.

Thus the Amphibia appear to be related to the Elasmobranchii in two ways—
first through the Dipnoi, second through the Crossopterygii. In like manner, the

Text-fig. 1.

Diagram to illustrate the affinities of Vertebrata and their relative importance in Primary,

Secondary, and Tertiary times.

. Amphibia and Amniota.

. Crossopterygii.

. Dipnoi. ¢ Primary.
. Elasmobranchii. al

Ganoider ihe Secondary.

. Holocephali. Tertiary.

. Stegocephali.

. Teleostei.

Teleostei are related to the Elasmobranchii in two ways, the Crossopterygii and
the Ganoidei.

To attempt to give a definite chart of the Ichthyopsida would be to assume a perfect

knowledge of the structure, development, and paleontology of the various groups

which I do not pretend to possess. I will therefore give a mere diagram (text-fig. 1)

in order to illustrate my meaning, and pass on to the facts of development as observed

OF THE LARVAL POLYPTERUS. 317

in this larval Crossopterygian, attempting such interpretation as they seem to warrant,
in view of the absence of knowledge of the early stages in its development.

I].—MarTEeErIiAu.

The external features of the larva of Polypterus, which forms the subject of this
paper, I have described in a former paper!. I have had at my disposal only a single
specimen, measuring 30 mm., obtained during a collecting-trip to the Gambia in 19002.
In the present paper I have given an account of the structure of the cartilaginous
skeleton in this larva, and somewhat of its subsequent development as studied in a
number of specimens measuring from 9 cm. upwards. I have also given an account
of the genital and excretory system of organs in this small larva, the subsequent
development of which I have already described in a previous paper ®.

It will be seen that between the stage of this small larva (30 mm. in length)
and the next stage at my disposal (namely, specimens 9 cm. in length) there is a
considerable gap. As regards the study of the development of the skeleton, this is
of no importance, as the intervening stages are easily interpreted. As regards the
development of the genital ducts, however, an intermediate stage, between that here
described and that of the 9 cm. larva already described, is much to be desired. Of the
developmental stages of Polypterus preceding that here described hitherto nothing
has been observed. :

It may be said of this larva that it exhibits the condition of the last of the series of
changes which is undergone by Polypterus in its development from the egg before it
assumes the external appearances of the adult form. The term “larva” has frequently
been employed for young Polypteri of all sizes which retain the external larval gill;
but as this gill is retained frequently by adult specimens of some species of Polypterus,
it is in no way justifiable to term such specimens as happen to possess this organ
‘‘Jarvee,” irrespective of their being in a larval condition otherwise.

I have laid some stress upon this, as an account of the excretory system of a larval
Calamoichthys has been published, in which I am sure that the author has been
influenced in his description by the supposition that the specimen was in a larval
condition, though measuring 12 cm. in length. But to this I shall return later.

MeErtuHops.

The larva, which had been preserved in 5 per cent. formalin, was cut into transverse
sections, of which the anterior half were 10 » in thickness, while the posterior half
were 7 » thick. ‘They were doubly stained with hematoxyline and eosine. All the

* Trans. Zool. Soc. London, vol. xvi. p. 118.
* In the account of the external features, this larva was said to be of Polypterus lapradi. I has recently
been shown by Mr. Boulenger that the larva is that of P. senegalus and not that of P. lapradii.

* Trans. Zool. Soc. London, vol. xv. p. 323.
222

318 MR. J. 8S. BUDGETT ON THE STRUCTURE

figures of Plate XXXIII., and figs. 9 and 10 of Plate XXXIV., were drawn from
reconstructions by Kerr’s method ; that is, the sections were drawn on sheets of ground-
glass by the aid of the camera lucida and a medium, of the same refractive index
as the glass, run in between the sheets of glass 1.

I have found it extremely convenient to use this method in the following way :—
Five dozen sheets of ground-glass 4 inches square and 4; inch thick are ground
and polished en masse, so that their cut edges when placed together form plain
surfaces.

After having drawn the first section, the image of the second section is exactly
superimposed on the drawing of the first, which is then removed, and the next glass
plate being put exactly in its place and the drawing having been made the image ot

Text-fig. 2.

Apparatus used in reconstructing.

the third section is exactly superimposed on the drawing of the second, and so on.
In this way all the successive sections have the same register as the first, and when
placed together in the form of a cube the magnified image of the object is formed.

The cube of glass plates is then transferred plate by plate to a cubical glass jar, the
width of which is a little more than the diagonal of the plates, so that the cube of
glass can just freely rotate within the square vessel. ‘The vessel contains a mixture
of fennel-oil and oil of cedar, which I have found to be sufficiently near the refractive
index of the glass, and to have the advantage over clove-oil that it does not become
dark with age.

The cube of plates is held in position by means of the glass turn-table shown in
text-fig. 2. It consists of a cireular disc of plate-glass, the diameter of which is very

* Quart. Journ, Mier. Science, vol. xly. pt. 1, p. 6.

OF THE LARVAL POLYPTERUS. 519

slightly less than the width of the vessel, so that it can rotate freely on the bottom of
the vessel. A second and similar dise of glass has four segments cut off it in such a
way that when placed together and cemented to the first disc, so that their circum-
ferences coincide, there is formed a trough which will exactly carry the cube of
glass plates.

If they fit properly the plates must stand vertically, and the cube of plates can be
rotated on the turn-table so that the reconstructed image can be seen from any aspect
by an observer always looking normally at the surface of the fluid, ¢. ¢. the side of the
square vessel.

No image, of course, can be seen when the cube is so turned that the observer looks.
between the surfaces of the plates, but with a very slight turning from this position
the image at once comes into view.

If it is desired to reconstruct only a small series of sections, the remainder of the
cube can conveniently be made up of squares of thick plate-glass (see text-fig. 2) in
place of thin mat-surface squares.

ITI.—TuHeE SKELETON.

The Chondrocranium.—The cranial anatomy of the adult Polypterus has been made
known by Traquair1, while that of the half-grown Polypterus was described by
Pollard 2.

In this small larva, measuring 30 mm., there is as yet but slight traces of ossification,
and that only in the membrane-bones of the head. The primordial cartilaginous
cranium may therefore be said to be at the height of its development.

The auditory capsule, though fused with the occipital and parietal region of the
cranium anteriorly, posteriorly is separated from the exoccipital region by a very
large foramen, giving exit to the xth and xith cranial nerves (Pl. XXXIII. fig. 4,
X., XI.). From this foramen a fissure extends between the auditory capsule and
the supraoccipital region, and likewise a fissure between the auditory capsule and the
basioccipital region. ‘The exoccipital cartilage, though fused dorsally with the supra-
and ventrally with the basioccipital regions, is yet easy to recognize as a neural arch,
which is becoming fused with the cranium (Pl. XXXIII. fig. 4, Hv.occ.). The base
of this neural arch has the same form and position as the base of the first true neural
arch of the vertebral column, in front of which the first spinal nerve has exit
(Pl. X XXIII. fig. 4, Sp.7.).

The basioccipital region does not completely envelop the anterior end of the
notochord, but is composed of two halves (the parachordal cartilages) abutting on
the two sides of the front end of this structure (Pl. XXXIII. fig. 2). Posteriorly

* Journ. Anat. & Phys. vol. v. (1871).
? Zool. Jahrb. Anat. u. Ont. Bd. vy. (1892).

520 MR. J. 8S. BUDGETT ON THE STRUCTURE

these two lateral masses of cartilage send wings ventrally, which meet and fuse below
the dorsal aorta, enclosing it in a short canal which is roofed in by the notochord
itself (Pl. XXXIII. figs. 2 & 4, s.d.br.). Anteriorly to the bifurcation of the
aorta, the basioccipital cartilages fuse below the notochord, sending forward a
median narrow plate of cartilage which underlies the tip of the notochord
(Pl XXXIII. fig. 3, s.Ch.dr.). The fused auditory supra- and basioccipital regions
form on either side an exceedingly massive cranial wall. ‘These walls are united
dorsally by a fairly solid bridge of cartilage of shortest extent antero-posteriorly in the
middle line (Pl. XXXIII. fig. 2, s.oc.br.). | Ventrally, however, they are only
connected by the two little bridges of cartilage already mentioned—the one passing
underneath the dorsal aorta behind its bifurcation, the other below the tip of the
notochord in front of the bifurcation of the aorta.

In front of the tip of the notochord the floor of the cranium is formed merely
of membrane, the bases of the lateral walls of the cranium being widely separated by
a very large fontanelle in the posterior region of which les the hypophysis!. The
hypophysis is not at this stage enclosed ina special pocket of the cranial wall or
“sella turcica,” but curving backwards lies close under the hind end of the mid-brain
(separated from it by thin membrane) and above the dermis of the roof of the mouth.
In a 9 em. specimen the glandular part of the hypophysis is much larger in proportion
and the membrane separating the hypophysis from the floor of the mid-brain has been
converted into cartilage of considerable thickness, while the special cavity so formed
remains in communication with the rest of the cranium by the opening for the passage
of the infundibulum.

On the dorsal surface of the auditory region there extends forwards from the
anterior end of the fissure separating the supraoccipital region from the posterior
end of the auditory capsule a fairly pronounced ridge. On the lateral surface, along
the line of the horizontal semicircular canal, there is a very pronounced pterotic ridge
bearing in its middle portion the articulatory surface for the head of the hyo-
mandibular cartilage (Pl. XX XIII. figs. 1, 2, & 3, Pt.r.). The front portion of this
ridge gives off the sphenotic wing, which separating from the cranial wall passes
forwards as a horizontally flattened bar of cartilage to fuse again with the cranial wall
in the supraorbital region (Pl. XX XIII. figs. 1 & 3, Sph.).

‘ At this stage the glandular part of the hypophysis is very small and flattened against the dermis of
the roof of the mouth; its tubules open anteriorly into a small cavity which is in communication with the
mouth-cavity by a fairly wide duct, which persists until after the larva has grown to 9 cm. in length.
According to Bickford (Anatomische Anzeiger, Bd. x. p. 469), this duct remains permanently open in
Calamoichthys. The nervous portion of the hypophysis has a very wide lumen and passing backwards ends in
five finger-like processes. In the 9 cm. specimen these have branched and become mingled with the tubules
of the glandular portion posteriorly, but do not appear to be continued into them as stated by Waldschmidt
(Anatomische Anzeiger, Bd. ii. p. 518).

OF THE LARVAL POLYPTERUS. 321

On the ventral surface of the auditory region of the cranium, from the point in
the middle line where the aorta bifurcates, on either side there extends forwards and
outwards a deep groove in which runs the branch of the aorta, being the efferent artery
from the hyoid external gill, and receiving a small branch from the first branchial
arch.

Anterior to the bridge of cartilage uniting dorsally the two lateral masses of
cartilage of the auditory region, the roof of the cranium is formed entirely of
membrane to the front end of the cranial cavity, except for a delicate but continuous
bridge of cartilage in the region of the pineal body (Pl. XX XIII. figs. 1 & 3, Ep.br.).
This slender bridge expands towards the middle line into a horseshoe-shaped plate
(Pl. XXXIV. fig. 1, Ep.br.) lying over the vesicle of the third ventricle!. The pineal
gland itself lies in the centre of the horseshoe, and is not covered by cartilage but lies
in the dermis of the skin (Pl. XXXIV. fig. 1, Ep.).

The lateral walls of the cranium extend forward from the auditory region on either
side of the alisphenoid region as continuous vertical plates of cartilage, somewhat
dumbbell-shaped in section and perforated by foramina for the iiird, vth, and viith
nerves in the thinner middle portion (Pl. XXXIII. fig. 1, III., V., VII.). In the
sphenethmoid region there is a large lateral fontanelle closed only by membrane
through which passes the optic nerve, while above and below this membranous portion
there pass the thickened upper and lower cartilaginous borders of the cranial wall,
connecting on either side the ethmoidal region with the posterior region of the
cranium (Pl. XX XIII. figs. 1 & 3). A section therefore passing through the middle
of the orbital region cuts merely four bars of cartilages—two supraorbital bars separated
from one another by a wide superior fontanelle, and two infraorbital bars (trabecule
cranii) separated by a wide inferior fontanelle, the upper and lower of each side
being separated by the large lateral fontanelle; the greater part of the “ sphen-
ethmoid” bone of Folypterus is therefore not preformed in cartilage.

In this region the section of the supraorbital bar of cartilage is V-shaped ; the outer
limb of the V is the anterior prolongation of the sphenotic wing, which is here fused
with the supraorbital bar (Pl. XX XIII. fig. 3, Sph.). In the angle thus formed
lies the supraorbital canal of the lateral line system (Pl. XXXIV. fig. 1, s.0.c.). In
front of the interorbital region the four bars of cartilage in the side walls of the
cranial cavity expand and unite together, forming the anterior wall of the cranial
cavity and being fused with the olfactory capsules (Pl. XX XIII. fig. 1). A canal for
the passage of the olfactory branches of the vth and viith cranial nerves penetrates the

‘ This vesicle is called by Waldschmidt the “ epiphysis cerebri (pineal gland)”; in reality, however, it is the
homologue of the median vesicle of Lepidosteus described by Balfour and Parker (Phil. Trans. Roy. Soc. Lond.
part ii, 1882). The epiphysis itself lies over and behind this vesicle, and was apparently not found by
Waldschmidt in Polypterus (loc. cit.)

322 MR. J. S. BUDGETT ON THE STRUCTURE

outer portion of the supraorbital bar of cartilage at the point where it is fused with
the olfactory capsule (Pl. XX XIII. fig. 1, fol.). Just anterior to this the capsule
itself is penetrated by the same nerve. ‘The olfactory capsules are very large and
thin-walled, oval-shaped, and perforated anteriorly by a crescent-shaped nasal aperture
(Pl. XXXII. fig. 1). They are separated from one another to some extent anteriorly
by a deep groove which ends above a spade-shaped rostral prolongation of the ventral
portion of the nasal septum.

The ventral side of the olfactory capsule bears a facet for the articulation of the
anterior end of the palato-quadrate bar of cartilage (P]. XX XIII. fig. 1, P.Qu.art.).

The general form of the primordial cranium at this stage resembles very much that
of the Selachii, especially the Scylliide, but in the absence of cartilage in the middle
portion of the cranial walls, and the size of the great fontanelle, there is some
similarity to the Urodela. The bridge of cartilage across the supracranial fontanelle
seems to indicate a former roofing of the cranial cavity by cartilage, for, later, this
bridge is represented by the small plate of cartilage noted by Pollard, and finally
disappears. ‘The absence of cartilage immediately over the pineal gland seems to
indicate that the cranial roof was formerly perforated by a parietal foramen.

The Visceral Arches—YVhe palatoquadrate bar is a pyramidal mass of cartilage, the
anterior corner of which is drawn out into a vertically flattened bar, which anteriorly
becomes almost circular in section, and finally flattened horizontally to form the
articulation with the facet on the ventral side of the nasal capsule (Pl. XX XIII.
fig. 1, P.Qu.art.). The quadrato-mandibular articulation is saddle-shaped, and it is
in the region of this articulation that the palato-quadrate bar has its greatest transverse
diameter (Pl. XX XIII. figs. 1, 2, 8, P.Qu., ME.).

Behind this articulation the bar narrows to a point, which is concave vertically.
This concavity rests upon the lower limb of the hyomandibular cartilage. ‘The palato-
quadrate bar receives no direct support from the cranial wall; the articulation is
therefore hyostylic.

The mandibular bar has a similar pyramidal shape posteriorly, while its anterior
portion forms a more regularly cylindrical rod than the palato-quadrate bar, and tapers
to the symphysis with its fellow (Pl. XX XIII. figs. 1, 2, 3, Wh.).

The hyoidean arch, consisting of hyomandibular, stylohyal, ceratohyal, and hypohyal
cartilages, articulates with the facet already mentioned on the underside of the lateral
ridge of the auditory region (Pl. XX XIII. figs. 1, 2, 38, Pé.r.).

The hyomandibular consists of two rounded masses connected by a slender curved
rod bearing upon its posterior convex surface the anterior end of a rod of cartilage
segmented into two fairly equal portions, which constitute the skeletal axis of the base
of the external gill (Pl. X XXIII, figs. 1, 2, 3, Op.). This rod persists as the small
nodule of cartilage on the inner side of the opercular bone, which has been before
noted by Van Wijhe and Traqnair.

OF THE LARVAL POLYPTERUS. 323

The stylohyal (Pl. XX XIII. figs. 1, 2, St.Hy.) is a rounded mass of cartilage which
takes no part in the suspension of the jaws.

The ceratohyal (Pl. XX XIII. figs. 1, 2, 3, C.Hy.) is massive at either end, but
constricted to a narrow bar in its middle portion.

The hypohyal (Pl. XXXIII. figs. 1, 2, 3, H.Hy.) is an almost spherical cartilage
connecting the front end of the ceratohyal with that of the 1st branchial bar.

The basibranchial (P|. XX XIII. figs. 2, 3, B.Br.) is a massive median cartilage on
either side of which are articulated the enlarged lower ends of the four branchial bars.
Each of these bars, in passing backwards and upwards, becomes very slender.
Posteriorly these become slightly thickened again and curve inwards; finally the
upper end of the first branchial abuts upon the cranial wall just below the articulation
of the hyomandibular, while the 2nd, 3rd, and 4th branchials tapering, curve
downwards and end freely close under the auditory capsule (Pl. XXXIII.
figs 2, 3,cbn. 1512573, & 4).

Between the palatoquadrate and mandibular cartilage there lies a crescent-shaped
labial cartilage with its convex surface forwards, the upper horn being more slender
than the lower (Pl. XX XIII. figs. 1, 3, Zd.).

In the arrangement of the cartilages of the suspensorial apparatus the larval
Polypterus exhibits a condition exactly intermediate between that of the hyostylic
Selachians and the Teleostei, there being no very intimate union between the palato-
quadrate and hyomandibular cartilage by means of asymplectic cartilage corresponding
to that of Teleostei. The general correspondence of the arrangement with that of the
larval Salmon on the one hand and the hyostylic Selachii on the other, and
the relation of the spiracle to the hyomandibular in Polypterus, seem to me to go
a long way towards dispelling doubts as to the homology of the suspensorium of the
Teleostei with that of the hyostylic Selachii, such as have been entertained by some
authors!. In this particular of course Polypterus differs widely from all living
Amphibia, where the palatoquadrate bar has become fused with the cranial wall and
the hyomandibular usually reduced.

On the other hand, the presence on the hyomandibular of Polypterus of a segmented
rod of cartilage supporting the external gill is paralleled in the Aistopodous
Stegocephali; for in Dolichosoma longissimum, according to Fritsch ?, there is found
attached to the hyoid arch a skeletal structure which apparently supported an external
gill. It is difficult, however, to make out whether this structure was attached to
the periotic portion of the skull itself or to the upper end of the hyoid arch.

1 See H. B. Pollard, “‘ The Suspension of the Jaws in Fish,” Anatomische Anzeiger, x. p. 17. Also Parker
and Haswell, ‘ Text-book of Zoology,’ vol. 11. p. 202.
2 Fauna der Gaskohle und der Kalksteine der Permformation Bohmens.

VOL. XVI.—PartT vii. No. 2.—October, 1902. 3A

vo
bo
=

MR. J. 8. BUDGETT ON THE STRUOTURE

The Vertebral Column.

The notochord is at this stage of even calibre throughout the greater part of its
length, tapering suddenly, however, anteriorly and gradually posteriorly towards
its termination, where it shows a slight upward tendency (Pl. XXXIII. figs, 4.
5, 6, Ch.).

The structure of the notochord in Polypterus is very similar to that of Lepidosteus
and the ‘l'eleosteans. ‘The meshes between the large vacuoles enclose here and there a
nucleus. The vacuoles towards the sheath become smaller and the nuclei more
numerous, and pass rather suddenly into a definite nucleated epithelium lining the
sheath of the notochord (Pl. XXXIV. fig. 10, Ch.ep.). The sheath itself is very
thick and almost structureless, being from 5 to 31; the thickness of the diameter of
the vacuolated portion of notochord. A very delicate membrana elastica bounds the
sheath externally (Pl. XXXIV. fig. 10, m.el.e.) and separates it from the connective
tissue surrounding the notochord with which the septa between the muscles are
continuous.

At the junction of these septa with the notochordal sheath are found on either side
three metameric series of cartilages—a dorsal row of stout pyramidal masses forming
the bases of the neural arches with which they are continuous (Pl. XX XIII. figs. 4,
5, 6, & Pl. XXXIV. fig. 2, n.pr.); a lateral row of small pyramidal masses forming
the foundations for the transverse processes and lateral ribs (Pl. XX XIII. figs. 4, 9,
& Pl. XXXIV. fig. 2, /pr.); and the ventral row of still smaller nodules forming
the foundations of the ventral series of ribs (Pl. XX XIII. figs. 4, 5,6, & Pl. XXXTYV.
figs. 2 & 10, v.pr.).

Ail these cartilages rest directly on the notochordal sheath, and in each metamere the
three masses lie in nearly the same transverse plane, so that one section often passes
through all three structures.

Neither the pyramidal bases nor their neural prolongations are fused across the mid-
line, except in the tail-region. The bases are quite separate, while the upper ends of
the two halves of the neural arch curve backwards, come into close contact with one
another, and carry the lower end of the median dorsal spine (Pl. X XXIII. tigs. 4, 4,
6, d.sp.).

In the anterior region of the vertebral column all three series are well-developed.
In this region the lateral series are continued outwards along the septa, between the
dorso-lateral and the ventro-lateral muscles, forming complete rib-like structures
(Pl. XXXII. fig. 4, U.pr.).

The ventral series are also well-developed and pass outwards between the ventro-
lateral muscles and the kidneys (Pl. XX XIII. fig. 4, & Pl. XXXIV. figs. 2 & 10, v.pr.).
At this stage they do not in the anterior region reach the peritoneum.

OF THE LARVAL POLYPTERUS. 325

In a section passing between the myomeres, and therefore through the bases of these
cartilages, somewhat further back, it may be seen that the section cuts small nodules of
cartilage at the extremity of the septa between the dorso-lateral and ventro-lateral
muscles (Pl. XXXIV. fig. 2, 0.l.r.c.). These outer nodules lying near the nerve of the
. lateral line are not, however, connected with the cartilage of the central end of the
septum. That is to say, the cartilage which forms the basis of the outer portion of
the lateral ribs is developed independently of the cartilaginous basis of the transverse
process,

In the middle region of the vertebral column both the lateral and ventral cartilages
are small, while the dorsal cartilages of the two sides are seen to be placed in a slightly
alternating position, so that a transverse section passing through the centre of a dorsal
cartilage on the right side will pass through the posterior fringe of the dorsal cartilage
of the left side (Pl. XX XIII. fig. 5, n.pr.).

In the caudal region the lateral series of cartilages are not found, while the ventral
cartilages, though retaining their position, become the greatly enlarged hemal arches.
The first pair of enlarged ventral cartilages, however, do not unite ventrally, but each
half bears at its extremity one of the last two interspinous cartilages of the anal fin 1
(Pl. XX XIII. fig. 6, /.v.pr., r.v.pr.). The two preceding interspinous cartilages of the
anal fin are borne by similar rods of cartilage, which, however, do not unite with the
ventral cartilage.

The most anterior cartilage of the anal fin is somewhat expanded antero-posteriorly,
but is not supported by the hemal cartilage.

Behind the anal fin the right and left ventral cartilages fuse together below the
hemal canal to form rod-shaped median cartilages, which expand distally and
support directly the rays of the ventral fin of the diphycercal tail of Polypterus
(Pl. XX XIII. fig. 6, h.c.).

In this region the right and left halves of the neural arches fuse together to form the
dorsal spines (Pl. XX XIII. fig. 6, d.sp.), while wedged in between these are found the
interspinous processes, which, expanding distally to trumpet-shaped masses of cartilage,
support the rays of the dorsal fin of the tail. There is no correspondence between
the dorsal spines of the neural arches and these interspinous processes, for there
may be one, two, or three of the latter intervening between two of the former. More
anteriorly these interspinous processes become much reduced and do not penetrate
between the dorsal spines. As the extremity of the tail is reached the neural and

" I have satisfied myself that my description of the way in which the anal fin is supported in this specimen
is correct, but I am not quite sure that this will be found to be the normal arrangement. It seems, at any
rate to me, to be an additional proof that the hemal arches are formed from the bending downwards and
uniting of originally separate ventral ribs, which have secondarily assumed the function of supporting the

anal] fin.
B) A

326 MR. J. S. BUDGETT ON THE STRUCTURE

hemal arches, together with the interspinous processes of the dorsal fin, become more
and more oblique, lying almost parallel to the notochord (Pl. XXXIII. fig. 6, d.sp.,
l.sp.). Finally there lies upon the dorsal, and also upon the ventral, side of the notochord
a flattened mass of cartilage, which appears to be composed of the rudiments of several
neural and hemal arches (Pl. XX XIII. fig. 6, fn.pr., fv.pr.). The notochord extends .
beyond this incomplete cartilaginous tube, a bare filament embedded in the fin-rays of
the tail.

At this stage there is no trace of any intervertebral cartilages, neither is there any
trace of a ring of cartilage enclosing the intervertebral regions of the notochord.

In older specimens of 9 cm. length considerable deposits of bone have appeared,
producing important changes in the structure of the vertebral column and its
processes.

In the vertebral regions the cartilaginous bases of the neural arches and lateral
processes are still seen, though now surrounded by bone, deposited in the connective
tissue adjoining the notochord (Pl. XXXIV. figs. 3, 4, 8, n.pr., U.pr.). The ventral
cartilages have disappeared from the neighbourhood of the notochord. The bony
deposits which haye enclosed the lateral cartilages and formed the transverse processes
have caused the proximal ends of the ventral cartilages to recede outwards, and these
are now found attached loosely to the underside of the transverse processes below their
attachment to the lateral bony ribs, which have now become formed in the connective
tissue of the septa between the dorso-lateral and ventro-lateral muscles (Pl. XXXIV.
figs. 5, 4, 7, tv.pr.). ‘The ventral cartilages themselves form the heads of the ventral
bony ribs which have now become formed at the junction of the septa between the
successive ventro-lateral muscles with the peritoneum (Pl. XXXIV. figs. 4, 7, v.pr.).

The shifting outwards of the heads of the ventral ribs or hemal arches with the
development of the large transverse bony processes of the vertebre has resulted in
allowing space for the greatly enlarged kidneys.

It will be seen that the heads of these ventral ribs do not now lie quite in the same
transverse plane as the transverse processes, but crossing them diagonally project
towards the muscles in front of the transverse processes (Pl. XXXIV. fig. 7). In the
full-grown Polypterus the heads of the ventral ribs articulate with the intervertebral
regions of the vertebral column, that is, between two successive vertebre, and it might
be thought that this was their original place of attachment. It will, however, be
understood, from the above description of their mode of growth, that they are
originally attached to the ventral surface of the notochord in the same transverse plane
as the bases of the transverse processes, that is, vertebral in position, and that they later
lose their connection with the notochord, become twisted across the ends of the
transverse processes, and with the subsequent development of the bony centra become
attached again to the vertebral axis, and are finally ¢xtervertedral in position.

OF THE LARVAL POLYPTERUS. Bath

The centra themselves are at this stage very thin and hourglass-shaped, expanding
widely anteriorly and posteriorly; they are not formed previously in cartilage
(Pl. XXXIV. fig. 8, ¢.) except for the small neural and lateral cartilages which they
enclose ; they directly surround the chordal sheath. There is, however, a single layer
of cells separating them from the latter in the position where the membrana elastica
externa should be, which somewhat resemble cartilage-cells; they do not, however,
stain in the very characteristic way in which all other cartilage in this specimen has
stained (Pl. XXXIV. fig. 6, m.c.). The cartilages of the neural arches play but a very
small part in the formation of the bony neural arches, which are also formed directly
in connective tissue.

In specimens 15 cm. long the vacuolated portion of the notochord has become
constricted vertebrally, while the sheath of the notochord, retaining a considerable
thickness in the vertebral region, intervertebrally becomes greatly thickened
(Pl. XXXIV. fig. 6, Ch.sh.). It is this thickening of the notochordal sheath which
is the chief cause of the great expansion of the bony vertebre in the intervertebral
regions. At this stage all trace of cartilage has disappeared from the composition
of the vertebra (Pl. XXXIV. fig. 5).

The formation of the vertebral centra in Polypterus is very much on the same lines
as that of Lepidosteus and the Teleostei. It differs from Lepidosteus in the absence of
the intervertebral rings of cartilage which give rise to the proccelous articulations in
that form, and from Amia in the absence of intercalated cartilages. In the possession
of three pairs of vertebrally placed cartilages resting upon the notochordal sheath
before the commencement of bone formation, Polypterus differs from all living
Vertebrates.

That Polypterus is provided with a double set of ribs has long been known; and by
some authors the upper series has been homologized with the ribs of Elasmobranchii,
Amphibia, and Amniota, and the lower series with the ribs of the Dipnoi, Ganoidei, and
Teleostei. Géppert especially! has developed this view regarding the reduction of
the lower series in the former groups as due to the suppression of the ventro-lateral
muscles. The starting-point which Goppert took was the condition in Calamoichthys
at the stage where the lower ribs are attached to the under sides of the upper ribs
shown in Pl. XXXIV. fig. 4 of Polypterus. The discovery that all the lower ribs in
Polypterus have their origin in a ventral series of cartilages resting directly on the
notechordal sheath seems to me to very much strengthen his views. ‘The absence of
intercalated cartilages, such as are found in the majority of Vertebrates exclusive of the
Teleostei or of the intervertebral cartilage-rings of Lepidosteus, may possibly be
connected with the early and great development of membrane-bone which is
so characteristic of the development of all the skeletal structures of Polypterus.

* Morph. Jahrb. Bd. xxiii.

328 MR. J. S. BUDGETT ON THE STRUCTURE

The Shoulder-girdle and Pectoral Fins —The cartilaginous shoulder-girdle consists
of a compact mass of cartilage of considerable thickness anteriorly, and, though thinning
out ventrally, of no great extent in a dorso-ventral direction (Pl. XX XIII. fig. 7).
Posteriorly, it is prolonged as a thin plate of cartilage, towards the hinder border of
which is the great coracoidal foramen (Pl. XX XIII. figs. 7 & 8, Corf.). Above this
foramen is situated the protuberance bearing the convex facet which articulates with
the proximal ends of the pro- and metapterygial cartilages of the pectoral fin. From
behind, this protuberance appears as a distinct short rod of cartilage attached only at
its proximal end to the flattened portion of the shoulder-girdle (P]. XX XIII. fig. 7).
In reality, however, it is continued forwards into the anterior thick portion of the

girdle as a thickened ridge.

Text-fig. 3.

POLYPTERUS

HEPTANCHUS
LARVAL POLYPTERUS

Skeleton of pectoral fin of Polypterus and Heptanchus.

Pectoral fin of—1. Adult Polypterus.
2. Larval x
3. Heptanchus.

Meta. Metapterygium. Mes, Mesopterygium. Pro. Propterygium.

The pectoral fin of Polypterus is one of its most characteristic features, being unlike
that of all other Vertebrates excepting its congener Calamoichthys. It is therefore
a question of considerable interest as to what is the relation of this fin to other known
types, and how has it been formed. Upon this question two views have been held :—
(1) The fin of Polypterus has been derived from a biserial archipterygium of the type
of Ceratodus by the shortening of the axis and the shifting of the proximal radials up
the axis to form the meta- and propterygia. This view has been mainly held by

OF THE LARVAL POLYPTERUS. 329

Klaatsch? and Gegenbaur °, though Gegenbaur appears now® to derive it directly
from forms with a very short axis. (2) The fin of Polypterus has been derived from a
uniserial fin of the type of Heptanchus or, perhaps better, Chlamydoselache by the
shortening of the metapterygial border and the fusion of the bases of the radials to
form the expanded mesopterygium.

Now the development of the fin might be expected to throw some light on this
question, and in the 30 mm. larva this is what we find :—The general shape of the fin
is quite different from that of the adult. The shape of the fin-blade is triangular,
the metapterygial border forming with the distal border an acute angle, while the
propterygial border forms with the distal border an obtuse angle (text-fig. 3. 2).

The cartilaginous skeleton of the pectoral fin differs in many important points from
the skeleton of the fin of the adult Polypterus. The propterygium extending along
the preaxial border of the fin is stout but short, being scarcely more than one-third the
length of the metapterygium extending along the postaxial border, and being situated
almost at right angles to the latter (Pl. XX XIII. fig. 8, Pro.). The angle between
these two rods is filled by a flattened blade of cartilage, which is, however, slightly
thickened where it is in contact with the metapterygium (Pl. XX XIII. fig. 8, Mes.).
Distally this flat blade or mesopterygium is split in a fan-like manner to form the
cartilaginous bases for the radials. The distal ends of these re-unite to form a
continuous border of cartilage. The mesopterygial blade is irregularly punctured for
the passage of blood-vessels (Pl. XX XIII. fig. 8, b.v.f.). On the free edge of the
metapterygium, at its distal end, is a slight flange of cartilage, seemingly forming
a rudimentary continuation round the distal end of the radial cartilages.

In fact the pectoral fin of the larva is not strictly a crossopterygium, but is a
uniserial fin which can be directly compared with that of the Selachii.

The Pelvic Fin.—TVhe cartilaginous skeleton of the very small pelvic fin consists of
a rod of cartilage unsegmented and slightly curved, approximating its fellow at the
anterior and posterior ends, but nowhere uniting with the latter (Pl. XXXII.
fig. 9, Bas.). ‘The anterior extremities taper slightly and diverge, there being no
indication of a distinct pelvic portion. Posteriorly these rods expand outwards and,
as they penetrate the body-wall, each becomes split into four or five finger-like rods,
some of which may re-unite distally. These form the cartilaginous bases of the radials
(Pl. XX XIII. fig. 9, 7).

The development of the pelvic fin throws but little light on the morphology of the
fins of Polypterus, but seems to confirm to some extent the view here taken from
the development of the pectoral fin, that they have been derived from a uniserial type
by shortening of the postaxial border, rather than from a biserial type by shortening of
the median axis.

1. Festschr. von C. Gegenbaur, part i. p. 261 (1896).
* Jen. Zeit. vil. 1873. * Morph, Jahrb. xxii. p. 119.

530 STRUCTURE OF THE LARVAL POLYPTERUS.

1V.—URINOGENITAL ORGANS.

The excretory system of this larva is of especial interest, for here we find that
a regular metamorphosis is taking place. The larval pronephros, though still
functional, shows signs of degenerating, while the mesonephros is still fairly simple
in its arrangement, and in some respects is still in a larval condition.

The pronephros consists of a rather small glomus almost filling the pronephric
chamber which lies close by the aorta (Pl. XXXIV. fig. 9, G/.); from this a narrow
tube embedded in lymphoid tissue, the pronephric duct, passes outwards dorsal to the
posterior cardinal vein and towards the body-wall (Pl. XXXIV. fig. 9, pnd.) ; on
passing between the dorsal and ventral lateral muscles it suddenly dilates, turns
headwards, loops round the brachial nerve, and, in a mass of lymphoid tissue lying in
the angle between the anterior ends of the dorso-lateral and ventro-lateral muscles and
the skin, becomes greatly convoluted. In the successive convolutions the duct
becomes narrower and narrower, occasionally becoming dilated and then suddenly
narrower again; finally there leaves the convoluted mass a very fine duct
(Pl. XXXIV. fig. 9, s.d.), and this, running along the outer side of the posterior
cardinal vein, passes backwards and inwards until it comes to lie just over the
peritoneum. Two segments behind the glomus of the head-kidney it gives off the
first kidney-tubule, and thence passes straight to the hind end of the body-cavity
as the segmental duct, ever increasing in size until it meets its fellow to form the
urinary sinus (text-fig. 4, w.s.).

The smallness of the pronephric chamber and the dilatation of the convoluted
portion of the pronephric duct must be regarded as signs of degeneration. In fact the
connection between the pronephros and the mesonephros could not be traced on
the left side, while on the right side it was done with the utmost difficulty. The
glomus itself on the left side was very small, and the anterior end of the coiled
pronepric duct could not be traced all the way to it.

On the right side there appeared to be traces of a peritoneal funnel leading to
the pronephric chamber (Pl. XXXIV. fig. 9, Pf); but with the thick sections into
which I had cut this region (10%) I was unable to satisfy myself that it actually
opened into this chamber.

In specimens 9 cm. in length all trace of the pronephros had disappeared, there
remaining in its place a small mass of lymphoid tissue.

When we compare the pronephros of Polypterus with that of the Ganoids and
Teleosteans which have been described, there can be no hesitation in saying that
it resembles most closely the pronephros of Amia described by Jungersen!, where
there is one pronephric chamber, one peritoneal funnel, and one opening of the
pronephric duct into the pronephric chamber. ‘To draw a close comparison between

* Zool. Anz. 1894, p. 246.

Text-fig. 4.

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Diagram of kidney-system of larval Polypterus.

Projection from transverse sections of entire pronephros and mesonephros of the right side of the larva
of the female Polypterus, x 60. The pronephros is a dorsal view of the same reconstruction as that
figured in Pl. XXXTY. fig. 9.

g!. Glomus of pronephros. m.ceps. Glomerulus.
conv.pn. Convoluted pronephric duct. mucps.a. Accessory glomeruli formed between
neph. Nephrostome. the original glomeruli and the seg-
v.pr. Position of ventral process marking mental duct.
the metameres. s.d. Segmental duct.
kt, Kidney-tubule. u.s. Urinary sinus,

o>
i=]

VOL. XVI.—ParT vil. No. 3.—October, 1902.

532 MR. J. 8. BUDGETT ON THE STRUCTURE

the pronephros of Améa and that of Polypterus is not possible, seeing that the stage I
have described is undoubtedly only the last stage in the history of the pronephros.

Acipenser } has a very long pronephric chamber, with at first six, later four, funnels
leading from the pronephric chamber.

Lepidosteus, according to Beard ?, has also at first a long chamber with three
funnels, later a shorter one with two, and finally, according to Balfour ® and Parker,
only one funnel leads from the pronephric chainber.

It is of course conceivable that at an earlier stage Polypterus has more than
one funnel leading from the pronephric chamber ; but I think that this is not probable,
seeing how widely is the glomus separated from the convoluted portion of the duct.

Lebedinsky* has described the pronephros of Calamoichthys as mingled with the
anterior tubules of the mesonephros, somewhat as Semon describes the pronephros in
Ichthyophis°®. Seeing, however, that his ‘larve” measured 12 cm. and 15 cm.
respectively, I think it would be surprising if in these young Calamoichthys there
should remain traces of a pronephros which in Polypterus is already degenerating at
3 cm., and has completely disappeared at 9 cm. It is still more surprising that the
larval head-kidneys of two creatures so closely allied as Polypterus and Calamoichthys
bear no resemblance one to another. But it is not clear to me by what means the
author of this account has distinguished between the tubules, ‘outer and inner

’

funnels,” &c. of the pronephros from those of the mesonephros. I am bound

to conclude therefore that what Lebedinsky has described as “Vorniere” in
Calamoichtiys are some of the anterior tubules of the mesonephros, possibly accessory
undeveloped ones, and that the pronephros (“ Vorniere”’) has already disappeared.

At this stage the mesonephric tubules are already becoming complicated in the fore
part of the body. ‘There are from two to five glomeruli to each body-segment, and
about the same number of tubules opening into the segmental duct (text-fig. 4). The
accessory glomeruli and tubules arise close to the segmental duct, while the older
formed ones become displaced and are found nearer the dorsal aorta towards the
middle line (text-fig. 4, m.eps.). In the hinder half of the mesonephros the glomeruli
become fewer and fewer, and the arrangement of the tubules simpler, while to each
body-segment there is now found one glomerulus and one tubule opening into the
segmental duct (text-fig. 4, 4.t.). Throughout this portion of the body there is found
lying immediately to the outer side of the genital ridge (ovary) and ventral to the
segmental duct a strip of thickened peritoneal epithelium (Pl. XXXYV. figs. 1, 2, 3, 4,
5, 6, 7, 8, ov.d.); this will eventually form the dorsal wall of the oviduct. From the
twenty-fourth to the fortieth segment there is found opening upon this thickened ridge
in each segment a nephrostome communicating with the glomerulus (Pl. XXXY.
figs. 8, 4, neph., & text-fig. 4, p. 331).

* Jungersen, Zool. Anz. 1893, pp. 464, 469. * Anat. Anz. Bd. x. p. 94.
* Loe. cit. * Jen. Zeitschr. 1891.
° Arch. mikr. Anat. xliv. p. 216,

OF THE LARVAL POLYPTERUS. 339

Section I. (Pl. XXXYV. fig. 1) is taken through the twenty-fourth segment, and
shows the thickened strip of peritoneum in section lying to the outer side of the
mesentery of the genital ridge (ovary) and the more complicated arrangement of
tubules.

Section IT. (Pl. XXXYV. fig. 2) is taken through the twenty-ninth segment, and
shows the thickened ridge (ov.d.) in section lying to the outer side of a small
projection which here represents the genital ridge (g..). It also shows the accessory
tubules on either side and the accessory glomerulus of the right side (4.t.d., m.cps.a.).
The arrangement of the older tubules is here less complicated.

Section III. (Pl. XXXYV. fig. 5) is through the thirtieth segment, and shows on the
left side a nephrostome opening upon the thickened ridge and communicating with
the glomerulus (neph., m.cps.). On the right side accessory tubules are shown (.t.2.).

Section IV. (Pl. XXXYV. fig. 4) is through the thirty-fourth segment; on the left
side the edge of a nephrostome and also of a glomerulus is cut through (neph., m.cps.),
while on the right side is shown a single large glomerulus from which a kidney-tubule
leads (m.cps.).

Section V. (Pl. XXXV. fig. 5) passes through the thirty-seventh segment, and shows
the openings of two kidney-tubules into the right and left segmental duct (/.¢.). The
thickened ridge still persists, though the genital ridge does not extend so far back.

Section VI. (Pl. XXXV. fig. 6) is very near the hind end of the body-cavity
behind the last kidney-tubules. ‘The thickened ridge of peritoneum is still seen lying
under the segmental duct (ov.d., s.d.).

Section VII. (Pl. XXXYV. fig. 7) is right at the end of the body-cavity; the
segmental ducts are now turning ventralwards and approaching each other (s.d.), while
the thickened ridge still lies just ventral to them (o0v.d.)

Section VIII. (Pl. XXXV. fig. 8) passes just in front of the vent, behind the point
of union of the segmental ducts. The body-cavity is seen here to be prolonged
backwards in two portions on either side divided by a septum (d.¢:); in the upper
portions is still seen the thickened ridge of peritoneum (vv.d.). ‘This upper portion is
the commencement of the folding-off of the oviduct from the body-cavity by the
forward growth of the septum, and it is at the point a that the oviducts eventually
open into the urinogenital sinus. The lower portion of the body-cavity ends
posteriorly at the point where the abdominal pores later break through (a.p.).

The further stages in the folding-off of the oviducts from the body-cavity I have been
unable to observe, as in my next stage (9 cm.) the formation of the oviducts 1s already
complete, though their posterior ends still end blindly in the wall of the urinary
sinus. It is hardly possible to doubt, however, that the thickened ridge which we have
traced through the posterior portion of the body-cavity forms eventually the dorsal
wall of the oviduct. That is to say, we have, in the Polypterus larva, a row of nephro-
stomes opening into that portion of the body-cavity which will eventually become the
genital duct.

3B2

534 MR. J. 8. BUDGETT ON THE STRUCTURE

In Lepidosteus, Balfour and Parker! found that the hollow ovary was formed by the
ventral edge of the ovary growing round and fusing with the peritoneum, thus including
a portion of the body-cavity. Into this cavity in the larval Zepidosteus they found
nephrostomes opening ; but Balfour says that he could not observe how the hind ends of
the oviducts were formed, but admitted that if there should be found nephrostomes
opening into this portion of the duct, it would prove that the oviducts of Lepidosteus
are not true Miillerian ducts. Now this is precisely what we have in Polypterus.
Jungersen * has shown that the ovary of many Teleosteans is formed by the inclusion

Text-fig. 5.

- fe ™.Cps.
. Wie (
sad. ! Gon a

IG” néph
LARVAL 9? LARVAL °
5} wee eA ra 7. ” 8. p§$
gg ay } we OZ Vef:

ADULT 9 ADULT ¢ ADULT of ADULT ¢

Sata

POLYPTERUS LEPIDOSTEUS POLYPTERUS LEPIDOSTEUS .

Series of diagrams illustrating the suggested homologies of the genital ducts and vasa efferentia in
Polypterus and Lepidosteus.
neph., nephrostome of tubule passing to glomerulus; m.cps., glomerulus ; g.gr., thickened strip of peritoneum
or genital groove; g.r., genital ridge; s.d., segmental duct; ¢.d., testisduct; ¢., testis; ov., ovary ;
v.ef., vas efferens ; ov.d., oviduct.
The dotted line in 3, 4, and 7 indicates that the nephrostomes no longer persist. 5 and 6 indicate a condition
believed to exist, but not yet proved.

of a portion of the body-cavity much as Balfour and Parker described the process in
Lepidosteus, but, so far as I am aware, no one has found nephrostomes opening into the
ducts of the ovary. It seems fairly certain, then, that in the female Polypterus the
genital duct is not a Miillerian duct, that is, is not developed from the segmental duct.

In a previous paper * I described the genital duct in the male Polypterus, and gave
reasons for regarding the genital ducts in the male and female as homologous structures,
showing that in young specimens 9 cm, in length the hinder ends of the ducts in the

1 Loc. cit. * Arb. Inst. Wiirzburg, Bd. ix. 1889.
* Trans. Zool. Soc. Lond, vol. xy. p. 323,

OF
oo

(Sh)

OF THE LARVAL POLYPTERUS.

two series had a very similar appearance, but I was unable to show their actual origin.
I have now indicated the origin of the genital duct in the female.

On re-examining my sections of the young male 9 em. in length, I find an indication
.that the posterior part of the genital duct is formed in the same way, namely, by a
folding-off of a groove in the ccelomic wall on the outer side of the genital ridge
(Pl. XXXYV. figs. 9, 10, ¢.d.).

Now this is precisely the region where in the female I have found the nephrostomes
opening, and I can but suppose that the larval male possesses them too in early life.
That is to say, in all probability, in the larva of the male Polypterus there will
be found nephrostomes opening into that portion of the cclom which becomes
folded off to form the male genital duct. If, then, nephrostomes were retained in the
adult, we should have formed a series of tubules connecting the genital duct with the
glomeruli of the kidney; and if the genital duct ceased to perforate the wall of the
urinary sinus the genital products could find their way out through the kidney,
and the nephrostomes would be converted into vasa efferentia, similar to those of
Lepidosteus and other Ganoidei, of Elasmobranchii, Dipnoi, Amphibia, and Amniota.

I suggest, then, that since I have previously given reasons for supposing that the
genital ducts in the male and female Polypterus are homologous, the discovery of these
nephrostomes opening into the female duct precludes the possibility of their being
homologous with Miillerian ducts, but indicates a possible homology with the longitu-
dinal canal of the testicular network of those forms in which such a network occurs,
and the possible origin of the vasa efferentia, leading thence to the kidney, from
nephrostomes.

Upon this view the genital ducts of Polypterus, Ganoidei, and Teleostei have arisen
from a condition similar to that of the Cyclostomata, where the generative products are
shed into the ccelom and pass into the ureter through genital pores. In Polypterus
similar genital pores opening into the ureter upon a papilla are very early formed in
male and female. From this condition, by the formation of first a groove, then a canal
opening into the body-cavity anteriorly, and finally a canal continuous with the genital
gland, the genital products were conducted outwards. Into this canal there opened a
number of nephrostomes, which in the male of all forms except Polypterus and the
Teleosteans took up the spermatozoa and became the vasa efferentia (text-fig. 5).

It is true that there is very little ontogenetic evidence of this mode of the formation
of the vasa efferentia. But the fact that in all forms where nephrostomes leading from
the ceelom to the kidney persist they are absent in the region of the testicular network,
would fit in with the view that the nephrostomes in this region have been used to

form the vasa efferentia.
Jungersen in his work on the genital ducts of Teleosteans1 cites evidence brought

1 Loe. cit.

536 MR. J. S. BUDGETT ON THE STRUCTURE

forward by Siebold and by Brock, that in certain Teleosteans in which the testes are
hollow, the cavity of the testis, and therefore probably also of the testis-duct, is formed
by a folding-off of a portion of the ccelom.

Jungersen came to the conclusion that in all Vertebrata except Elasmobranchs the
oviducts were homologous and formed by a folding-off of a groove in the coelomic wall.
If this conclusion is correct, then there is a difficulty in the way of the view I have put
forward which it is not easy to overcome. In many forms which possess a testicular
network there is also found, in the male, a more or less rudimentary female genital
duct usually called a Miillerian duct. It seems unlikely, then, to say the least of it,
that, in these forms, the longitudinal canal of the network in the male and the genital
duct of the female can be homologous, for these structures occur side by side in the
males.

If the ducts of Ganoidei and Teleostei really are homologous in the male and female,
while in the other Gnathostomata they are not homologous, then either the female
duct or the male duct cannot be homologous throughout the Gnathostomata.

It can, I think, hardly be doubted that the male and female ducts in Teleostei are
homologous. I have before given reasons for thinking that they are so in Polypterus.
It remains, then, to decide whether it is more likely that the male duct in Polypterus is
homologous with the longitudinal canal of Lepidosteus and so with that of other forms
in which a testicular network occurs, or that the female duct in Ganoidei, Crossopterygil,
and Teleostei is homologous with the female duct of other Gnathostomata, as held by
Jungersen.

‘The male duct of Polypterus lies in exactly the same position as the blind longitu-
dinal canal of Lepidosteus, and it is difficult to avoid the conclusion that these ducts
are homologous with one another, and again that this canal in Lepidosteus is the
longitudinal canal of the testicular network of other forms,

Jungersen! admits this comparison, but derives the male duct of Polypterus and
Teleostei from the fusion of a testicular network with the loss of its connection with

the kidney, which he, with Semon? and Kerr? and many other authors, regards as the.

primitive condition. But Jungersen * also holds that the female ducts are homologous
throughout the Gnathostomata. ‘The presence of the rudimentary Miilerian duct in
many forms with a testicular network makes it impossible on this view to regard the
ducts of male and female in any vertebrate as homologous structures, as they appear to
be in Teleostei.

Supposing, however, that the female ducts in Polypterus, Ganoidei, and Teleostei are
not homologous with those of Elasmobranchii and Amniota, as their position in the
hind end of the body-cavity, and the presence in Polypterus and Lepidosteus of

1 Zool. Anz, xxiii. Bd. No. 617, * Jen. Zeitschr. 1891.
* Proe. Zool. Soc. 1901, vol. ii. p. 493. * Arb. Inst. Wiirzburg, Bd. ix, 1889.

OF THE LARVAL POLYPTERUS, 397

nephrostomes opening into them, makes very probable, then we may regard the male
and female ducts of Cyclostomata, Crossopterygii, Ganoidei, and Teleostei as homologous,
and the female ducts of other Gnathostomata as independent structures, 7. ¢. Miillerian
ducts. It is now known that these Miillerian ducts arise as a splitting off from the
Archinephric duct only in Elasmobranchs, but this difference in the mode of origin of
the oviducts is not considered by many authors to constitute a proof that they are not
homologous. The peculiarity of the oviducts of these groups (Elasmobranchii, Dipnoi,
Amphibia, and Amniota) in tending to appear in the males as more or less rudimentary
structures, seems to me to be a strong argument in favour of their being homologous in
these groups; and it is very noticeable that these rudiments are usually, if not invariably,
absent in the Crossopterygii, Ganoidei, and Teleostei, those groups, namely, in which the
oviduct in the female appears not to be homologous with the Miillerian ducts but
rather with genital ducts of the male.

Summary of the Structure and Development of the Urinogenital Organs.

The pronephros of Polypterus is beginning to degenerate in the larva 30 mm. in
length. At this stage it consists of a small pronephric chamber containing the glomus
and of a duct leading from the chamber to pass to and become the duct of the
mesonephros, and consisting of three portions—a very narrow portion leading outwards,
a dilated and much convoluted portion lying close under the skin, and a very narrow
portion leading inwards and backwards to become the segmental duct of the
mesonephros.

The pronephros of Polypterus resembles very much that of Amia.

The mesonephros anteriorly is at this stage becoming complicated. Posteriorly it
has still a segmental arrangement, each segment being provided with one Malpighian
corpuscle with its tubule leading to the segmental duct and its peritoneal funnel. The
peritoneal funnels open upon the rudiment of the oviduct, which is not yet folded off
from the celom. ‘The genital pores do not yet penetrate the walls of the urinary
sinus.

From examination of somewhat older specimens, the male and female ducts appear to
arise in a somewhat similar manner, and it is regarded as probable that in the young
male larva the peritoneal funnels open upon the rudiment of the male duct. It is
suggested that these peritoneal funnels, if they persisted, would then answer to the vasa
efferentia passing from the longitudinal canal to the Malpighian corpuscles of
Lepidosteus.

‘The male and female ducts of Crossopterygii and Teleostei are regarded as homolo-
gous structures, which in the males of other Gnathostomata have been gradually
absorbed in the testicular network, and in the females of other Gnathostomata except
the Ganoidei are replaced by Miillerian ducts.

308 STRUCTURE OF THE LARVAL POLYPTERUS.

Whatever be the true interpretation of the genital ducts in the Ichthyopsida, the
Crossopterygii, Teleostei, and Ganoidei are closely united in this respect, the latter group
appearing to stand in closer relationship to the rest of the Gnathostomata than the
former groups.

V.—CONCcLUSION.

We have seen, then, that in its development Polypterus shows affinities in various
directions. The development of the pectoral fin and of the cranium and visceral arches
has some resemblance to that of the Elasmobranchii, while of course the spiral valve, the
conus and optic chiasma in the adult are other structures common to the two groups.
The development of the vertebral column is not very dissimilar to that of the Teleostei,
though in the possession of lateral cartilaginous processes in addition to the neural and
ventral processes of the Dipnoi, Ganoidei, and Teleostei, Polypterus presents a very
generalized condition; while there can be no doubt that from the standpoint of
urinogenital organs both the larval and adult Polypterus are as closely connected with
the Teleostei as even Amia itself. It has, however, been admitted by the most
competent paleontologists that the structure of the dermal bones of the head and of
the shoulder-girdle of Polypterus is so like that of certain Stegocephali, that it must be
regarded as more than a mere resemblance, while there are many points in the
development of the skeleton that distinctly approach the condition of the Amphibia.
The only possible interpretation of these facts appears to me to be that the living
Crossopterygians form a central group among recent forms having some characters in
common with most of the great groups. Seeing that it is thus a generalized form
and is not very different from the ancient Devonian Crossopterygii, it seems to me
not improbable that the particulars of structure in which it resembles the admittedly
recent Teleostei are in both groups of a primitive nature. I do not pretend that upon
this point I feel very certain, but I think I have put forward some evidence in favour
of the view I have taken.

It is with reluctance that I publish a piece of work the material for which consisted
of a single specimen ; but as there seemed to be no prospect in the immediate future of
an abundant supply of the early stages in the development of Polypterus being obtained,
and as upon examination I found that there were points of considerable interest in
this small larva, it seemed only right that they should be known. I trust, however,
that when more material comes to hand it will be found that what has been seen in
this larva has been accurately described.

PLATE XXXIIL

VOL. XVI.—PaRT vil. No. 4.—October, 1902.

340

Fig.

cr)

STRUCTURE OF THE LARVAL POLYPTERUS.

PLATE XXXIII.

. A side view of a reconstruction from transverse sections, 10 in thickness, of the right

half of the primordial cranium and visceral arches of the larval Polypterus. The great
afferent and efferent blood-vessels to the external gill are also shown. The last section
of the reconstruction cuts off the exoccipital region, the third and fourth branchial
arches, and the afferent and efferent vessels to the external gill.

. A posterior view of the same, reconstructed. The cut surfaces of the cartilage where

the reconstruction ends posteriorly are dotted. The anterior region of this reconstruction
has also been cut off just behind the nasal capsules.

Anterior aspect of the same. The cut surfaces are dotted. The portion reconstructed is
the same as for fig. 2.

Reconstruction of the left side of the occipital region and anterior end of the vertebral
column, showing that the exoccipital cartilage has still the form of a neural arch, though
already fused to some extent above and below with the cranium. The lateral and ventral
processes are seen to be very long in this region. The parachordal cartilages are shown
to send a bridge of cartilage under the aorta.

A dorsal view of a reconstruction of a portion of the mid-region of the vertebral cole
The dorsal spines have been cut off.

Reconstruction of the caudal portion of the axial skeleton showing the form of the neural
and ventral arches at this stage and the manner in which the anal fin is supported; also
the very slight upward tendency of the termination of the notochord.

. Reconstruction of the cartilage of the left half of the shoulder-girdle, seen from behind.

Reconstruction of the shoulder-girdle and left pectoral fin, seen from the front, showing
the great length of the metapterygium as compared with that of the propterygium and
the formation of the radials from one continuous plate of cartilage.

(Fig. 8 of this Plate is x 20; all the other figures are x 30.)

* The anterior end of this portion is to the right.

Trams, Lool. toc. Vol, AV. SU AAMW

JS.Bdel. E Wilson lith. Cambridge.

STRUCTURE OF THE LARVAL POLYPTERUS.

Fig.

Ki
Or.
12.

Fig.

4 (oh

i)

STRUCTURE OF THE LARVAL POLYPTERUS.

PLATE XXXIV.

. A section through the alisphenoid region of the head cutting the median vesicle, epiphysis,

and cartilaginous bridge in the region of the epiphysis, also cutting the trabecule cranii,
the sphenotic wings, and palato-quadrate bars. x 30.

A section through the vertebral region of the axial skeleton in the anterior part of the body
of the 830 mm. larva. Showing the neural, lateral, and ventral processes abutting on the
notochord, also the outer portion of the cartilages of the lateral ribs. x 30.

A section through the same region in a 9 cm. specimen, showing the encrusting bony
deposits forming the vertebre with their large transverse process. The ventrai processes
no longer abut on the notochord. x 22.

A similar section in the hind part of the body of a 9 cm. specimen, showing the carti-
laginous ventral processes now forming the heads of the ventral ribs attached to the
undersides of the extremities of the bony transverse processes. The ventro-lateral muscles
likewise have retreated from contact with the notochord. x 22.

. A section through the vertebral region of the axial skeleton in the anterior part of the

body of a 13 cm. specimen, showing the increased development of the bony vertebrz, the
complete suppression of the cartilages of the axial skeleton, and the vertebrally constricted
notochord. x 15.

A section through the intervertebral region of the same series as fig. 5, showing the inter-
vertebral dilatation of the notochord, especially of its sheath, which is enclosed in a single
layer of cartilage-like cells. x 15.

. A slightly oblique longitudinal section through the ventro-lateral muscles in a 9 cm.

specimen, showing the head of the ventral rib to the left containing the cartilage of the
ventral process and lying in front of the transverse process, and the continuation of
the ventral ribs outwards and backwards towards the right. The figure has been put
on the Plate in two portions. x 20.

. A section of the same series as fig. 7, but in the middle of the vertebral centra on the left,

sloping outwards through the sides of the vertebre towards the right. Two cartilaginous
neural processes are seen towards the middle of the figure embedded in the bony centra,
further to the right the section passes through the bony neural arch, while on the right
of the figure are seen two lateral cartilaginous processes. x 20.

. Is a reconstruction of the pronephros of the right side of the 30 mm. larva, and viewed

from the headward side, with the glomus lying under the notochord and the coiled
portion of the pronephric duct lying between the brachial nerve and the skin. The
notochord, dorso-lateral muscles, and ventro-lateral muscles are seen only in section. x 70.

10. Is a similar reconstruction of the most anterior mesonephric tubules of the right side,

showing that they do not lie in the same region of the body as the coiled duct of the
pronephros, but much nearer the middle line close under the notochord, and that they
end anteriorly quite suddenly. x 70.

Fans Bob Leo Vel HU PLAGE

alm

Tip
Chish.. GPP

Ulm. <

—

JS.B del . E Wilson lith. Cambridge

STRUCTURE OF THE LARVAL POLYPTERUS

Fig.

Fig.

ric
Fig.

lig.

Fig.

wo

5 (3h

ek

STRUCTURE OF THE LARVAL POLYPTERUS.

PLATE XXXYV.

. A section through the mesonephros of the 24th body-segment, showing the thickened strip of

peritoneum in section lying to the outer side of the mesentery of the genital ridge (ovary)
and the more complicated arrangement of the tubules in the anterior region.

. A section through the 29th body-segment, showing the thickened ridge lying to the outer

side of a small projection, which here represents the genital ridge. It also shows the
accessory tubules on either side and the accessory glomerulus on the right side. The
arrangement of the older tubules is here less complicated.

. A section through the 30th body-segment, showing on the left side a nephrostomic opening

upon the thickened ridge and communicating with the glomerulus. On the right side
accessory tubules are shown.

. A segment through the 34th body-segment ; on the left side the edge of a nephrostome

and also of a glomerulus is cut through, while on the right side is shown a single large
glomerulus from which a kidney-tubule leads.

. A section through the 37th body-segment, showing the opening of two kidney-tubules into

the right and left segmental duct. The thickened strip of peritoneum still persists, though
the genital ridge does not extend so far back.

A section passing near the hind end of the body-cavity behind the last kidney-tubules.
The thickened strip of peritoneum is still seen lying under the segmental duct.

. A section passing through the very end of the body-cavity; the segmental ducts are now

turning ventralwards and approaching one another, while the thickened strip lies just
ventral to them.

. A section passing just in front of the vent, behind the point of union of the segmental

ducts. ‘The body-cavity is seen here to be prolonged backwards in two portions on either
side divided by a septum. The thickened strip of peritoneum is here seen on the inner
side of the dorsal portion.

‘ig. 9. A section through the posterior end of the kidneys of a 9 em. male specimen, showing the

genital duct still in connection with the peritoneal epithelium.

10. A section of the same specimen further forwards, showing the large size of the genital

duct at the base of the testis.
(Magnification 80.)

Sram Loot, toc Vol AV IY ANAT”

J.S B.del E Wilson lith Cambridge

STRUCTURE. OF- THE LARVAL POLYPTERUS

b.c.
B.Br.

Br. 1, 2,3, 4.
Brn.
buf.

C.

Ch.
Ch.ep.
Ch.sh.
C.Hy.
conv.pn.d.
Cor.
Cor, f.
d.Ao.
d.l.m.
d.sp.
eg.af.
eg.ef.

Ep.
Ep.br.

Ex.xc.
f.npr.
f.ol.

f-v.pr.
G.x.
gd.

Gi.

gr.

gt 8.0.0.
he.
A.Hy.
Ay. M.

STRUCTURE OF THE LARVAL POLYPTERUS. 34

on

LETTERING OF THE FIGURES.

. Adipose tissue.

/- Alimentary canal.
. Anal fin.

. Dorsal aorta.

. Aortic supports.

. Abdominal pore.

. Auditory capsule.
. Basipterygium.

Body-cavity.

Basibranehial cartilage.

Branchial cartilages 1, 2, 3, 4.

Brachial nerve.

Blood-vessel foramen.

Centrum.

Notochord.

Chorda epithelium.

Sheath of notochord.

Ceratohyal.

Convoluted pronephric duct.

Coracoid.

Coracoidal foramen.

Dorsal aorta.

Dorso-lateral muscles.

Dorsal spines.

Afferent artery to external gill.

Efferent artery to external gill.

Epiphysis.

Bridge of cartilage in region of
epiphysis.

Exoccipital cartilage.

Fused neural processes.

Foramen for olfactory branches of
vth and viith nerves.

Fused ventral processes.

Vagus ganglion.

Genital duct.

Glomus.

Genital ridge.

Groove for the supraorbital canal.

Hemal cartilage.

Hypohyal.

Hyomandibular,

4.8.
k.

kt.
k.t.a.

Lb.

Lol.
Lpr.
Lr.

Lsp.

Lov.pr.
M.Cps.
M.Cps.a.
m.C.

m.el.e.
Mes.
Meta.
Mk.

m.v.
n.d.
neph.

npr.

N.S.

OSSPIB
Op.

. Ovary.

. Oviduct.

. Palium.

Intermuscular septum.

Kidney.

Kidney-tubule.

Accessory kidney-tubule.

Labial cartilage.

Left swim-bladder.

Lateral process.

Lateral rib.

Interspinous cartilages.

Left ventral process.

Glomerulus.

Accessory glomerulus.

Cartilage-like cells of membrana
elastica externa.

Membrana elastica externa.

Mesopterygium.

Metapterygium.

Mandibular cartilage.

Median vesicle of brain.

Neural arch.

Nephrostome.

Neural process.

Neural spine.

Outer cartilages of the lateral ribs.

Operculum,

. Posterior cardinal vein.

. Peritoneal funnel (traces of).

. Pronephric chamber.

. Pronephriec duct.

. Rudimentary continuation of

radials.

. Propterygium.

. Palato-quadrate cartilage.

. Palato-quadrate articulation.

. Pterotic ridge.

. Cartilaginous bases of radials.
. Right swim-bladder,

. Rectum,

. Right ventral process.

346

s.A.br.
Scp.

s.Ch.br.

s.d.

$.0.C.
S.oce.

s.0c.br.
Sph.

Sph.Eth.

Spi.

st,
St. Hy.

STRUCTURE OF THE LARVAL POLYPTERUS.

Subaortie bridge.
Scapula.
Subnotochordal bridge.
Segmental duct.
Supraorbital canal.
Supraoccipital region.
Supraoccipital bridge.
Sphenotic.

Cartilage of sphenethmoid region.
First spinal nerve.
Stomach.

Stylohyal.

. Point where oviduct will

. Testis.

. Trabecule cranii.

. Transverse bony process.
. Urinary sinus.

. Ventral aorta.

. Ventro-lateral muscles.

. Ventral process.

. Ventral rib.

open
into wrinary sinus.

IJ., I1I., V., &c. Positions of exit of cranial

nerves.

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VILL. On the Structure of the Larval Polypterus. ty J.§. Bupeett, M.A., F.Z.S.
(Plates XXXTIT-XXXV.). 24s sk Muara is gas heron 8 5)

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IX. Eedysis, as Morphological Evidence of the Original Tetradactyle Feathering of
the Birds Fore-limb, based especially on the Perennial Moult in Gymnorhina
tibicen. By Epwarp Decgn, /.Z.S.

Received October 16, 1901; read February 4, 1902.

[Plates XXXVIL-XXXVIIL]

ConTENTs.

Page
Ip IGNRROEINGHOIN?S Goo bodoooooodObab ooo gdoSOeEDObEuEOD UOoODHOOGKDaDeoaHOON OD 347
101, labitionicall oo sbconccoadsooboubooObdo ue oo oOo uHOonOKUAabeODDDdDoO OD oO OD DOUL 348
JUL, Wino G2 INSEMAN Casa osddooodno bn GooOKDOooODODOBDOUDOGD OO DOUGUIOOOND OO 351
IV. Explanatory Remarks on the Diagrams on Plates, Tables, and Charts............ 354
Wp Datiniion Ot CwioMle” 5 od oooanoce bUboeoonaooUHooD Od ODOODdDOCOODEoODOOOD 355
Ds Om GAckempinons Blumen” se ‘Geocasgacnc0nbou0anHeo0dK00000000 355
B. On the ‘“‘ Feathering of the Fledgling” ...............0 00sec ec eee reese 363
CROnk Perennial peat hermes rrrt iii reir er aerate terran ieicnd irks 365
VI. “ Orders of the Moult” in Gymnorhina tibicen 2.0... 6c cece eee eee ees 367

A. Flight-feathers or Penne alares= Remiges primores plus Remiges cubitales
(Sincovalll) ss opacvgnocsed oven oo omoadee sooo oosesaKoODDOG EH NORE 367
B. Remarks on the Period of Growth and the Development of the Remiges.... 371
C. The Bastard Wing. Alula or Ala spuria=Plume pollices.............- 371

D. Extract from and Remarks on the Table of Percentages for the Deficiency
ia Woy JRO ee We IMME: Go coagnanboooudoousuoUaHoonDCUDOGODOUN OS 375
KeUhrenWane-covextsvorlectricesiier eesti) tel Moricinetcncnor torr elena roialekatie teri 376
VIL. Summary of the Order in the Perennial Moult of the Wing-feathers ............ 390
VII. The' Contour Feather-tracts or Pteryle 2230.0. 20... eee ce en ene 395
IDX, CondMeHons cogssccasonpucsoboosooodnDoDDUoUOnGd DODO ObOD DD OO OSUDOONOOS 400
dx IMITOHIIN? pogo doodsuadebedsoanddoGudoboDGUUCUnb obo bo daoocedgGdNECGEDS 410
XUeE xplanationiomtheublateserertryrtoe cesehiereicuessRaleratreletaeiench nore teletereltekeLoretVeiiehouei 412

I.— INTRODUCTORY.

THE main object of this paper is to give additional evidence in support of the
theory of the derivation of the feathering of the bird’s wing.

When I was engaged on the subject of Diastataxy (Aquinto-cubitalism), the peculiar
conditions of the flight-feathers during the moult seemed to indicate that, by a fuller
study of the perennial moult, the facts concerning the observations of the feathers of
the bird’s wing might be considerably elucidated.

In order, then, to form a solid foundation for the purely morphogenetic development
of the feathers, it was necessary to ascertain the mode by which the perennial moult
of the individuals of a species of bird is made up, from the earliest to the last stages
of renewal; and, further, to what extent each feather participates in this annual

9

VOL. XVI.—Part vill. No. 1.—May, 1903. 3D

348 MR. E. DEGEN ON ECDYSIS.

process during the period of complete feather-change. This has been methodically
treated and fully explained in the present paper.

sy a “feather-change” there can be meant one thing only, namely, the actual
renewal of all the feathers.

Physical changes, arising from external agencies, such as colour-changes, or the
abrasion of the wing-coverts and contour-feathers of the body, with their attendant
effects upon the pattern of the plumage, do not enter into the scope of this work.
Neither do partial changes, such as spring-plumages and the various forms of nuptial
garbs, of a sexual nature; nor do the phenomena of “ Albinism” and “ Melanism,”
all these being either of a secondary origin, or, as in the latter case, of an etiological
nature.

I1.— HIstToricat.

With regard to the literature, it may be well to review in a general way those
papers which deal with the morphological history of the feathers. For a more
exhaustive account of the history of the “moult,” I refer the reader to the excellent
article of Dr. Allen (1), who has considered previous authors chronologically, and at
the same time has himself contributed to the physiology of the subject.

By far the most important addition to the subject of “‘moult”” was that made by
Blyth (4) in 1837, who, amongst other observations relative to colour-changes, makes
remarks on the plumage of birds which are of great value. Among many excellent
attributes characterizing his work, is that of a comparatively far advanced pterylo-
graphic knowledge before the time of appearance of the classic treatise of Nitzsch’s
‘ Pterylography,’ edited by Burmeister, and first published in 1840 (Translation, 37) 1.

Blyth’s work is replete with information, based principally on the “ Mallard” and
the ‘ Widgeon ”; but. though he bestowed much care on the partial and perennial
moult of the primaries and the tail-feathers, he treated but scantily the wing-coverts.
To this author's paper I have made frequent reference in the course of my own
research.

Schlegel’s famous “ Address” (40) gave a new impetus to the subject of ecdysis. I
shall have to allude more particularly in the course of my own work to the various

1 Yarrell’s endeavour to adduce evidence in favour of his view, “ that the feather itself becomes altered” *—
though in the course of his arguments he admits “that it is certainly difficult to understand how this
is so constantly effected in the web of the feather, where no vascularity can be shown to exist*, even when
the part is growing” (cf. Allen, J. c.),—is shared also by Blyth to a great extent. Burmeister’s observations
and researches into the histological structure of the feather (see Nitzsch, 7. c.), and also Holland (29), should,

however, finally dispel any doubts still existing on the point of a revitalization of the feather.

® These ztalics are mine.

MR. E. DEGEN ON ECDYSIS. 549

statements made by this author under the different chapters. Allen has criticized it
in a general way.

Amongst the principal dissentients from the laws formulated by Schlegel respecting
the season, manner, degrees, and methods of moult and alleged changes of colour
without moult, should be mentioned, as the foremost, Homeyer, who in ‘ Rhea,’ ii.
1846, p. 157, published some remarks ; he also replied to Schlegel in a communication
to ‘Naumannia’ (1853), and further by numerous comments on this subject (see
Bibliography, 30, 30 @, 31).

To the most prolific writers of that period who subjected the seasonal and other
changes to a fuller scrutiny, unquestionably belongs Brehm (6, 7, 8, 9, & 10) by
reason of a large amount of material gathered for this purpose by his son Alfred.
However, apart from the profusion of @ priori argument and some other additional
information, his inquiries had to a great extent the object of refuting the “ thesis” laid
down by Schlegel, and also similar views held by Martin (32, 33).

Important contributions to the knowledge of the chemico-physical changes in the
feather-structure itself were those of Altum (2), Meves (34), and Bogdanow. Mean-
while the question gave rise to a number of minor contributions, consisting of critical
remarks or casual observations on the subject, such as those of Gloger (24, 25, 26),
Hesler (28), Bock (5), Dwight (18), v. Miiller (36), Gatke (22), Cabanis, and many others.

Until the appearance of the translation from the Swedish of Sundevall’s work (43),
a great deal of confusion existed in regard to a scientific knowledge of the topography
of the feathering in birds. Sundevall has done much to remedy this deficiency, and
confined his researches largely to this character, though principally to the serial values,
of the feathers on the wing.

It is from this point that the researches conducted into the derivation of the
plumage began in earnest, as Nitzsch’s ‘ Pterylography,’ which appeared in 1840,
seems to have been little known or appreciated by his own countrymen, and it was not
until the able translation into English, published in 1867 by Dr. P. L. Sclater for the
Ray Society, was available that its worth became generally recognized. And in reading
Nitzsch, it is not a little remarkable to find that the portion dealing with the covert-
feathers on the wing should have received so little attention. Nevertheless, it is to the
last-named authors, Sundevall and Nitzsch (37), that we are primarily indebted for a
beginning of the study of the morphological question concerning the feathering of
the wings of birds.

After this, with the exception of twoshort papers in 1856 by Dr. Weinland—one in
Journ. f. Ornith. iv. pp. 125-129, and the other in Proc. Boston Soc. Nat. Hist. iv.
(1856-59) pp. 34-37,—a period of calm set in, which was broken only by the important
work published in 1866 by Dr. Fatio (19), who had meantime conducted a series
of investigations into the changes of the plumage, both chemico-physical and physio-
logical. ‘lo this memoir I have been frequently indebted.

0)

550 MR. E. DEGEN ON ECDYSIS.

After Fatio’s publication, the subject again lapsed, when it was reopened in 1877
with a short contribution by Gerbe (23). ‘To this author we are indebted for the
first allusions made to the genetic relations of the flight-feathers and their coverts.
Gerbe refers the student, at the beginning of his paper (which seems to have been
merely intended as a preliminary article), to some subsequent and more comprehensive
account of this subject. ‘This appears never to have been published. ‘This author's
researches do not extend beyond the flight-feathers and their principal coverts, as may
be seen on p. 290, /. ¢., pars. 9 & 10.

The next important memoir which appeared is that of Dr. Gadow (20), which
throws much light upon the physical and chemical aspect of the feather-structure.

Ignoring for the present a number of casual and disjointed observations which have
found their way into literature during this interval, we must look for the next really
important contribution towards a more orderly knowledge of the conditions deter-
minating the process of moult in birds to that made in 1896 by Dr. Wittmer
Stone (44).

Apart, however, from the prominent part which this author has allotted to the main
quills and other feather-tracts of the body, the object of his researches principally
centres in an elucidation of the relationship of the moult with the seasonal changes of
the plumage in as great a number of families, genera, and species of the birds of
North America as possible.

With the exception of the entries made on table iii., p. 116, of his work on the
relative condition of the smaller land-birds, no information is given about the covert-
feathers. To this work I have had to refer repeatedly in my arguments concerning the
different parts of the plumage.

Soon after this there appeared in rapid succession articles by John Guille Millais
(35), “On the Change of Birds to Spring-Plumage without a Moult” (referring to the
Grebe and Dunlin, but principally the Sanderling), and that by Dr. Chapman (13),
also on the Dunlin, the Sanderling, and the Snowflake.

In another paper in 1897, this latter author (15) also made some remarks in reply to
Dr. Chadbourne’s (11) exhaustive account of his observations on the “ Spring
Plumage of the Bobolink.” The last-quoted papers have mostly dealt with the question
of colour-change with or without moult.

Works with a more direct bearing upon the morphological features of the wings of
birds, and especially their coverts, are those of Goodchild (27), Wray (46), Gadow (21),
and Pycraft (38). More recently, again, Chalmers Mitchell (12) and Pyeraft (39) have
made attempts to arrive at a final solution of the question of Diastataxy. In these two
papers, which appeared contemporaneously, the interest attaching to the wing-coverts
as the most important factors was accordingly renewed, and is proportionate in amount
to the different standpoint taken up by these two last-named authors.

MR. E. DEGEN ON ECDYSIS. 351

J]I.—Metnop or ReskarcH.

The practice commonly adopted for the study of the moult is that of observing the
changes on birds living in captivity.

Confinement in cages and enclosures, however, as is well known, so greatly alters
the natural habits of birds that the information derived from this source is of too
uncertain a character to yield reliable results.

As an instance of this contention, I have to mention only the frequent occurrence
of the adoption of the plumage of the male by old female birds deprived of the
opportunity of pairing. On this point Dr. Fatio (19) makes the following statement
(p. 269, U. c.):—** Moreover, anyone may have remarked that a bird which has been
kept in captivity, or which has been partially deprived of the normal influences acting
from without, never attains the perfection of its plumage so completely as the individual
which is in a state of freedom” (translation).

Besides, there is abundant evidence for suspecting moult to be affected in those
species of birds which are of migratory habits. It is imperative, therefore, to take
into consideration the geographical range of such species when inquiring into the
subject. To show that this is the case with imported birds, I may quote the following
instances which came under my own observation :—

A two-year old Cacatua roseicapilla was transferred from Australia to London
during the months of October and November. It had just previous to departure
entered upon its regular annual moult, in accordance with conditions existing there;
this continued during the voyage, and the process was finished at the end of January,
which is the normal course for this species. About the month of June, in the same year,
this bird, in accordance with the alternating season, entered upon another complete
moult, which it terminated in October following, thus undergoing two complete moults
(inclusive of flight- and tail-feathers each time) within one calendar year, a totally
unnatural proceeding.

The other bird, a six-year old Parrot (Platycercus eximius), whose regular period
of annual moult in its native habitat is somewhat later, falling within the months of
December to March, on account of the wintry conditions prevailing here after its
arrival from Australia, suppressed this yearly process altogether till December of the
following year, which is the month corresponding with the regular conditions for this
moult in the southern hemisphere. Its plumage, on account of having been retained
for the two consecutive years, was consequently the worse for wear. (See also Bock (5),
p. 207, with remark by Dr. Cabanis.)

From these incidents we derive the further information that the latter and older
bird adhered to the moulting-season prevailing for the Southern, whilst the former

and younger bird, immediately upon transfer, adopted that of the Northern
Hemisphere.

352 MR. BE. DEGEN ON ECDYSIS.

Examples like the foregoing will therefore show the significance of the remarks
made on this head.

Without doubt a somewhat similar cause must have been responsible for the
greatly contradictory results obtained in the case of the “ Bobolink,” in the researches
made into the moult of this migratory species by Dr. Chadbourne (11) on the one
hand, and by Dr. Chapman (15) on the other. An inquiry into the geographical
yange of Dolichonyx oryzivorus discloses the fact that this species extends from the
north of Carolina, through Texas and Mexico, into the tropical belt of South America
north of the Equator. The chances, therefore, are that Dr. Chadbourne’s birds, having
been procured from a dealer, as he himself states, may have got into the latter's
hands from entirely different districts, and probably also from the extreme limits of the
geographical range of this species.

The other plan upon which to conduct the study of the moult, namely, that of
using the dried material of cabinets, has some equally serious drawbacks. It rarely
happens that a complete series for all the stages forms part of a general collection
(cf. Allen (1), p. 42). Useful no doubt, as this type of material proves to be in
providing supplementary evidence in doubtful cases, the different object, however, for
which it has been gathered does not, as a rule, recommend it for this purpose (cf, also
Wittmer Stone (44), p. 109).

My own method (and for which I have good reasons for reliability) has been that of
procuring, at regular intervals of one week, several specimens of the species named,
from the first signs of moult appearing, throughout the whole period of feather-
change.

By this means the birds can be examined at leisure while yet in a perfectly fresh
condition. ‘Their further preservation in alcohol is an additional advantage for re-
sulting them at any time when required for a comparison one with another.

This inquiry was conducted on 52 individual specimens, of which number 21 were
were males and 11 females. (See Table I. parts a & 0.)

Of this satisfactory series of specimens on which to base these observations, 27 enter
into the descriptions. ‘The remaining 5 specimens, nos. 28-32, which represent those
received at the end of the moulting-season, may, though they still show traces of
incomplete renewal of a few of the feathers of the trunk, for all practical purposes be
considered to have acquired the fully developed garb.

The first step taken in the present investigation has been that of measuring singly
each flight-feather in both wings of all the individual birds. This procedure, perhaps
unnecessary at first sight, has had the advantage of not only demonstrating the
numerous individual differences of lengths of these feathers in a given species, but kas

MR. E. DEGEN ON ECDYSIS. 3938

also proved to be of no inconsiderable value as a foundation in the compilation of the
comparative diagrams for the “* Remiges” (see Pls. XXXVI.-XXXVIII_).

These measurements, moreover, have been productive of a number of useful obser-
vations, which might otherwise have escaped notice. I may mention, for instance, the
case of the almost isolated condition of the development in rapid succession of primary
remiges III., 1V., and V., which attain their full lengths without having a correspond-
ing equivalent on the cubital portion of the wing (see Chart, Table II., p. 370, and
Diagram B, Plate XXXVL., left and right wing, showing the relative growth of the
flight-feathers, which are lettered c, d, and ¢ respectively).

This method has further afforded the means for estimating in percentages the
reduction in the power of flight through the loss of flight-feathers during the various
stages in the moult of the bird (see Table IIL., p. 374). That the length of corresponding
remiges is never alike in any two individuals seems conclusive, and it is enough, for
all practical purposes, to ascertain their mean length. ‘These averages were for the
Metacarpo-digitals or Primaries :—

: I. aTvat IY Wo VI. Wut, VIII. IX. XK.
TMG 3c0500 135 142 149 159 182 195 205 197 178 96

for the Cudbitals or Secondaries :—
I Il. INDE, Ve We VI. VII. VIII. EXG. Xe
TANNINS. oaaGo 132 Way 124 120 115 110 100 95 79 55

Possibly this procedure may appear somewhat artificial, but it has the advantage of
at least supplying approximate data for the ultimate length of those remiges which,
being in a state of partial development (or frequently shed altogether previous to their
replacement), in this way can be made available for exercising a control over the
deficiency caused by their loss.

In this examination some standard is necessary ; therefore, each flight-feather has been
theoretically reduced to the uniform length of 100, which figure represents its full length.

How this works out may be seen by a reference to the diagrammatic representation
of specimen No. 1 in Plate XXXVI. (left wing), and further marked A, in the
case of primary I., whose actual length is 110 mm. (expressed in the space on the
top), whilst its length in proportion to that of the full growth (7. ¢. 135 mm.) (see above)
is therefore oo =81:0, or in round figures 80, which is practically $ of its
ultimate length. Or to take the case of remex X., which is the shortest of the
primaries, whose mean length was ascertained to be 96 mm., as shown in specimen
No. 25, and further marked K on Plate XX XVIII. (see Table as in former), which repre-

sents this particular stage. Since its actual length was 65 mm. and its mean computed
: ; : BMD aoe
at 96 mm., the relative length therefore is, according to the adopted rule, ~}>— = 6777,

or practically 70—that is to say, 7% of its ultimate length.

354 MR. E. DEGEN ON ECDYSIS.

Thus, the comparatively slight discrepancies which must necessarily accrue from the
adoption of the theoretical, yet more serviceable, equivalents to those of the empirical
figures of their actual measurements, can exert no serious influence on the general

result of this investigation.

IV.—ExpLanatory REMARKS ON THE DIAGRAMS ON PxaTES, TABLES, AND CHarts.

From the 27 specimens more generally described, it seemed advisable to make
a narrower selection of 12 typical cases for the purpose of diagrammatic reproductions
which illustrate the relative stages of that particular phase which each remex pursues
during the moult.

In the diagrams allotted to them in Plates XXXVI-XXXVIIL,, these specimens
have received a special mark in the shape of a Roman capital letter, irrespective of
their serial numbers, which latter are those associated with the dates on which they
were received. With these the capital letters correspond tolerably well for denoting
the successive stages which are marked by a small Latin letter. ‘The reason for
this is that some birds commence to moult sooner than others, and in consequence
accomplish the moult earlier. For instance, specimen No. 16, marked F (see
Plate XX XVIL.), of Dec. 19, which repeats stage g, precedes No. 14, of Dec. 11, which
is marked G (Plate XXXVIL.), because this latter specimen has attained the stage of A,
which represents the growth of remex VIII. at an earlier date. A similar case to the
one mentioned is that of No. 24, and further marked M, of Feb. 18 (Plate XXXVIII.),
which had to be placed at the end for representing stage U/, or the development
of cubital V., as the last remex to appear, because it is a more typical specimen in
this respect than No. 25, in which the moult of the same quill has been seemingly
accomplished though not entered. Otherwise it bears the same date as the latter
specimen—a circumstance which is purely accidental, on account of their having been
shot together. Both of these, therefore, autedate No. 26, marked L (Plate XX XVIII.),
this having been procured on March 4, which represents the stages intermediate between
i and k, which are earlier than that of No. 24, as we have seen.

Many of these specimens being more or less a repetition only of those extracted for
diagrammatical representation, or calling for no special remarks, are referred to only
in a general way. Their quotients for the relative lengths of remiges in moult are,
however, entered, together with those specially selected for illustration, separately in
the two parts of Table I.: part a@ for the left and part 6 for the right wing (see
pp. 356-359).

The capital letters which the specimens received in Table I., parts « and 8, corre-
spond with those of the diagrams in Plates XXXVI-XXXVIII. The specimens are
arranged in Table I. in the order of the dates on which they were received. The
Roman figures placed at the head of the columns specify the order of the remiges for

MR. E. DEGEN ON ECDYSIS. 355

both the metacarpo-digital and the cubital portions of the wing. The column of
cyphers to the right contains the sums total of the amount of all the flight-feathers
under moult in each specimen. The cyphers placed at the bottom of the columns are
the sums total obtained for each remex itself, their aggregates agreeing with the grand
total of the other column in the right-hand corner. ;

The cyphers on the second line at the bottom show the number of specimens
observed for the moult of that particular remex, and beneath these, in opposition to
the numerical order of figures of the remiges at the top, are placed the letters referring
to the successive phases (cf. also diagrams on Plates XXXVI.-XXXVIII.), in alpha-
betical order, for the remiges of the hand portion. Their corresponding equivalents
for the order of the cubitals are designated by dashes, thus: '"'.

The symbol O signifies that the remex has been shed, and the dotted spaces are the
places still occupied by the old quills.

As already mentioned, a Table has also been provided for the percentages of
reduction of power of flight, giving the amount in each specimen, and for each portion
of the wing separately, the totals for each wing, and the grand totals for both sides.

V.—DEFINITION OF THE ** MOULT.”

A. On “ Adventitious Plumage.”

Before a bird assumes the deciduous plumage which is annually replaced in the
same manner, viz., by the process known as the * perennial moult,” it is provisionally
clothed with generally one, though often two liveries, differing both in function and
growth. They require careful consideration on account of their genetic importance.
The successive liveries are :—

_ An adventitious downy investment of the nestling, or “ Embryo-Plumage.”

. A non-deciduous (ontogenetic) garb of the fledgling, or “ Annual Plumage.”

_ A deciduous (phylogenetic) feathering of the mature bird, or “ Perennial
Plumage.”

So)

It is to the second livery that usually the term ‘“‘ embryo-plumage ” is given, chiefly
because it produces the first set of quills and contour-feathers ( Teleoptiles).

In the nestling of dasypedic birds a downy covering (Neossoptiles) of the body
precedes the latter or plumage of the fledgling. The term “‘ embryo-plumage ” there-
fore belongs to this downy adventitious covering : cf. Wittmer Stone (44), pp. 116-117,
‘Number and Times of Moult”; also Fatio (19), p. 258. These down-teathers
are the forerunners of the true contour- and covert-feathers, whose places the latter
afterwards occupy. They must therefore not be confounded with the downy structures
which grow in the interstices between the latter, such as are found in Ducks, Swans, &c.

VOL. XVI.—PakT vill. No. 2.— May, 1903. 3 E

MR. E. DEGEN ON ECDYSIS.

TaBLE I. a.—Showing the relative lengths of growth

LEFT
METACARPO-DIGITALS.
ieee 75 ee ee een epoca,
Date. | No.&Age. |Sex.] X. | IX | ae anal iae | ves |) any, 1] iene
| |
Lea OY pre vamenmetic | 1
WAeuNovemolen|) Jb ad 3 | 0
BAS 2,juv. | 3 19 | 62] 88
Bela es|) Siiny eo 13] 501] 80
diy) pee |S iil || 20
5 WAS) ase) | © 235) 71|\= 100) | ay
19) 5) Me juvaee lnc 0 65 100) 100
Clee Ois| Me azavad 3 4) 90| 100] 100
ieee) Chis |B 69 100 100) 100
ie Ul) Lp aa S 54| 91} 100
Da coer el Orrad g 9| 71] 100] 100} 100
I We Bes Mp | © | O 58 100 100. 100 |
Pe Pip 12, juv. | 2 | | 60 100. 100. 100
SP ait 13, juv. | 51 | 100; 100] 100
es gy ll 14, juv. | 9 O 2/ 56| 100] 100| 100] 100
| yo 15, juv. | 3 19 15 100, 100, 100
| » if 16, juv. | 3 48 | 94] 100] 100] 100
H. Jan. 1 17, ad 3 S3n lf W730 58a leOON TOON N00
ae Se 18, ad 3 24! 74!/ 100] 100]! 100
| eG 19, juv. | 2 33 85 | 100] 100] 100} 100
lah. gy 20, ad Ball ll ek 33 | 78| 100] 100] 100] 100
» 29 21, ad Ell © 70 | 100/ 100] 100] 100] 100} 100
= OD 22, ad Q 40| 82] 100] 100] 100] 100
29 23, juv. | 2 : u 0 48 | 871] 100| 100| 100
|M. Feb.18..| 24, ad alee 33 76| 100} 100] 100; 100/ 100
K 18..| 25, ad g | 67 | 78 | 100| 100} 100] 100} 100] 100
L. Mar. 4..| 26, ad g | 95 | 84 | 100] 100} 100] 100] 100 | 100
PAO ad g | 67 | 84 | 100| 100} 100] 100] 100 | 100
Totals .. 229 | 349 | 617 | 1022 | 1601 | 2212 | 2414 | 2503 | 26:
. |

| Number of specimens parti-
cipating in the moult of
respective quills ........

Is

| Order of the moults alpha-
| betically expressed .....

a k

6) stil 16 |e nas | 261) 27
| | | |
2

ie hueeTRaleeG, f C | d

For explanation of Tables on

of the main quills.

WING.

MR. E. DEGEN ON ECDYSIS.

O=shed to 100=full growth.

CUBITALS.

Vie |) vale

78 | 100
100.95
13 | 100
2 | 60

Totals.

341
542
420
259
718
692
846
1056
882
923
1069
1039
1008
1236
955
1210
1304
1168
1418
1440
1666
1852
1004
1787
1940
1883
1811

pp. 356-359, see pp. 354, 505,

357

MR. E. DEGEN ON ECDYSIS.

TasLe I. 6.—Showing the relative lengths of growth

RIGHT
CUBITALS.
Date. No. & Age. | Sex. S| ; VET. || VEL:
AG ENOVA (0). 1, ad. 3 73
Pe NOS 2, juv. 3 84
Bi #35) ae: 3, juy. fe) 68
Peo ears 4, Juv. 3 57
sh ae 5, Juv. 2 100
pH cal) Gs apa 3 100
KCN esl |eeienade 3 100 |
Ola 8, Juv. 3 100} 100
ecole 9, ad. 3 100 | 100
1D, gy SS:col| UO} excl. 3 100 25
|E. Dec. 3..) 11,juv. | 2 100 | 100
H B54) ian | © 100 | 15
ples ie |S 100 | 100
Ce pp tubo! Web a 2 100 45
py ool) UWS thier 3 100 90
W5 gy MQ coll IG, jo 3 100 50
ey Janene eealiarads 3 100 O
oy db soll leh, mal 3 100 40
& 16.5) 1, iae |S 100 | 100
Yo my UG ool) 20), ack. é 100 | 100
i Doo) Zl ak 3 100 | 100
® eBcol 2 eal Q 100} 100
Hy 2 Mosl| 23h iA Q 100
M. Feb.18..] 24, ad. 3 100 | 100
Kee Oke |eacowads 3 100 100
L. Mar. 4..| 26, ad. 3 100 | 100
mH baal iq aul, é 100 | 100
Totals .. 2 | 1465
Number of specimens parti-
cipating in the moult of 19
respective quills ........
Order of the moult alpha- f"
betically expressed ...... }

MR. E. DEGEN ON ECDYSIS, 359

of the main quills. O=shed to 100=full growth.
WING

METACARPO-DIGITALS.

1M al) NUE, IP aA Ve VAG) Weel, il) Waa |) 18S x Totals.
|

| — sess
| 63 O ip eh 291
100 90 1) 35 584

| 100 83 59 24 474 |

| 59} 40 3 258 |

| 100}; 100] 100 a 705 |
100 | 100 97 63 679
100 | 100} 100 87 7o9
| 100} 100 100 100 1069
| 100 100 88 of | 881
100 100 100 100 | 972
100 | 100 100 100 | 1061
| 100 100 100 100 | 981

| 100] 100] 100} 100 | 1016 |
100 | 100 100 | 100 | 1139
OOS SOO R00 87 1078
100 | 100}; 100; 100 1122
100 | 100} 100} 100 1298
100} 100) 100; 100 1146
100 | 100} 100} 100 1432
100} 100} 100 | 100 1442
100 | 100 100 100 1434
109 100 100 | 100 1346
100 100 100 100 1047
100 | 100 100 | 100 1752
100 | 100; 100} 100 1937
100 100} 100) 100 1744
100 | 100; 100) 100 1832
2622 | 2513 | 2422 | 2221 29481

27 27 26 25 Grand Total.
|
b G d é)

300 MR. E. DEGEN ON ECDYSIS.

Fatio (/. ¢. p. 252) mentions them as ‘“‘ Premiere livrée de lenfance,’ &c. From the
same author we also learn that the existence of the down-feathers is very brief, even in
those birds whose nestlings retain them during the earlier stages of development, until
their actual fledgling-plumage appears.

Structurally, these feathers belong to the filo-plumaceous type (Fatio, pp. 252-
254, /.¢.), giving the young bird the somewhat si/ky1! appearance of which Fatio
speaks.

The filo-plumaceous feathers are either pushed or borne out on the tips of feather-
papille of the more specialized plumage which follows on. This is formed in the
corium. The duration of attachment of the first livery to the new feathers varies
considerably ; it also varies according to families. (See also Fatio, /. ¢. p. 263.)

In some it is repeated through every feather-change, as in the Struthionide. In
the greater part of the Carinate this sessile condition is confined to the first change.
Cases of three simultaneous attachments of feathers are known to occur occasionally,
of which one is mentioned by Wittmer Stone (44), p. 112, for a Meadow-Lark. This
author also quotes the case observed by Will. Palmer in the ‘ Auk,’ 1894, of a young
Hooded Warbler, Sy/vania mitrata, in which the down! of the nestling was to be seen
at the tip of the feather of the first plumage, while the latter was ‘‘ in turn attached‘ to
the new feather of the winter plumage.”

In Struthious birds this latter phase seems to be of frequent occurrence, as I
myself have found several instances in the Emu (cf: also Fatio, /.¢. p. 253). These
filamentous sessile plumes are to be seen in a young Columba domestica tigured by
Pycraft (39), plate xvi. fig. 1, where they are supported by the main coverts which
are sprouting, and reference may also be made to my figure of a young Parrakeet
(Platycercus eximius) (see text-figures 1 & 2), where they are clearly defined for all
the series of coverts and contour-feathers.

I have not myself had the good fortune of proving the existence of these plumes on
the rectrices, but an observation was made by Brehm (8), p. 346, on this point in the
Owls, whose remark on it in the original is as follows:—

“ Die einjahrigen Vogel erkennt man tibrigens doch untriiglich daran dass die Spitzen
ihrer Steuerfedern, weil der Nestflaum auf ihnen gesessen hat, eine kleine Liicke in der
Mitte zeigen” }.

The important nature of this passage resulted in a footnote from the Editor
(Dr. Cabanis) to the following effect :—‘ Eine etwas suptile Wahrnehmung,” &c.; and
further, ‘die ober wohl beachtens werth scheint und jedenfalls wiederum von der
anerkannt scharfen Beobachtungsweise des Verfassers zeugt” ?.

Yet the nicety of this observation of Brehm, as pointed out by Dr. Cabanis, gains
in strength materially if we turn to a statement made by Blyth (4), who, on p. 260, in

1 The italics are mine.

MR. E. DEGEN ON ECDYSIS. 361

referring to the feather-changes in general, says :—‘“‘In the Widgeon, however,
and many other species, it will be found that the adult livery is obtained, in spring,
by an actual change of plumage, every feather being cast and renewed, except, of
course, the wing and tail-primaries!, And here it may be remarked that the two central
caudal feathers, which in all birds visibly differ from the rest, being of softer texture

Text-fig. 1.

Young Parrakeet, showing the filamentous plumes (neossoptiles) carried on the tips of the new contour-feathers.

and commonly of another colour, partake of the nature of the tectrices and wing-
coverts 1, and in double-moulting species are, like them, very usually shed and renewed
with the vernal renovation of clothing-plumage,” &c., &c.

Now, whether or not, Brehm, in his observation of Syrniwm, using the general term
of “rectrices” (Steuerfedern), had in mind the two centrally situated caudals only, does
not appear; in any case, it would seem that so far Blyth’s observation of the value

of these was fully confirmed.
' The italics are mine.

362 MR. E. DEGEN ON ECDYSIS.

If it could be shown that the “ primary” value of feathers could be established by
Brehm’s observation, we should become possessed of a good test for their serial value.
Having paid attention to this feature whenever a favourable opportunity presented
itself, in no case have I met with the sessile condition of these early plumes on the
flight-feathers, though they are present invariably on the main coverts, both dorsal
and ventral, according to my observation.

If, so far, we are supplied with even this slight means of differentiation between the
remiges and the rest of the covert- and contour-feathers, then we should have ample
proof that the principle of specialization, at any rate for the flight-feathers, is carried
out perceptibly early in the life of the bird; and this differentiation seems to be of
considerable genetic importance. Moreover, there is the well-known fact of the
unvarying absence of after-shafts in the case of both categories of flight-feathers.

It should be pointed out that Brehm (7 & 8) in his article, besides mentioning this
mode of replacement for the first plumage, also instances, by again referring to the
genus Syrnium, this peculiar condition as taking place during the second annual moult.
A repetition of this kind of renewal then naturally leads to the assumption of a
primitive condition of the plumage, to which the soft and downy feathering of the
Owls certainly points. And if we were to apply the existing analogy to some of the
Ratitw, the theory as to their descent from a bird which once possessed the power
of flight (Gadow (21), p. 667, quoting Ftirbringer) is not the less tenable on account
of their body-plumage still retaining this primitive style of feather-production, seeing
that such a combination still exists for the Owls.

I may mention here that owing to the yet more primitive conditions of the feathers
on the trunk in some of the Ratitw, the extreme tips of the after-shafts, which in the
Cassowary and the Emu attain a length equal to that of their main shafts, jointly
support the new-growth feather + with the latter.

Necessarily this throws a curious side-light upon the structure of the feather in the
Struthiones, as Beddard (3), p. 18, rightly suggests, under the heading ‘‘ Pterylosis,”
by concluding that “The feathers of those birds have been called intermediate between
contour-feathers and downs. Jt may be that they are primitive +,and that the struthious
birds have arisen from some ancient type in which the modern bird’s feather had hardly
been evolved ”?.

To a great extent, then, will this help to solve the true relationship of the after-shaft
to the main shaft (¢f. also Nitzsch (37), pp. 8 & 9). ‘The importance attaching to the
bifurcated follicle, as shown in the beautifully executed drawing of its desiccated cells,
known as the “soul” in the quill by Holland (29), on table 1., figs. 2 6 & 36, becomes
at once fully apparent. Their union occurs in the cavwm calami within the “corpus
calamus,’ of which the one branch deposits the substantia rhachidis externa for the

1 The italics are mine.

MR. E. DEGEN ON ECDYSIS. 365

main, and the other the same substance required in the building-up of the after-
shaft. In speaking of the latter, Holland, on p. 346, /.¢., says: ‘Bei Federn mit
Afterschaft bildet sich dem ersten gabelfo6rmigen Streifen gegeniiber am Bauche des
folliculus noch ein zweiter ahnlicher Langsstreifen, an denen dieselbe Bildung vorgeht,
wie wir eben gezeigt, und der folliculus lagert nach seiner vorderen und hinteren Seite
Mark ab. Wo das corpus calami beginnt verwachsen beide Schiéfte zw Spule”?.

Any doubts existing as to the structural plan of the primitive contour-feathers are
dispelled consequently by the retention in the Cassowary and the Emu of the original
feather-structure. This was a duplicated organ (see also Nitzsch, p. 9), of which the
two component parts—in the birds alluded to—are still of equal length and strength}.
These latter qualities are carried out to such a point of perfection that it is really
difficult to determine which is the rhachis and which the hyporhachis 2.

For the reduction of the latter (to 3 the length of the main shaft in the Grouse),
to its total disappearance, we get every degree of perfection in the develop-
ment for the main shaft of the feather towards that highest of degrees, as attained
by the Oscines amongst the Passerine birds at the expense, as it were, of the
after-shaft. This more highly specialized and simple form of feather, as acquired in
recent types of birds for perfected adaptation to flight, is then really only one-half of
the feather, and, however incongruous the inference may be, is a degeneration from the
original duplex structure.

B. On the “ Feathering of the Fledgling.”

A probably common feature of all the Carinate is the mode in which they acquire
the first set of flight-feathers. The supply of this first set of quills on the wing is
generally concurrent with the appearance of the greater portion of the contour-
feathers in the principal tracts of the trunk and on the head.

In the Gymnopedes the remiges appear somewhat in advance of the latter. They
also appear simultaneously with the upper major coverts by practically the whole
series shooting out along the posterior margin of the fore limb and in synchronism
(see text-figure 2, p. 364, of young Parrakeet). Indeed, the upper major coverts even
precede the remiges in some birds, judging from a statement made and figures given
by Pycraft (39) (ef. footnote, p. 251, & pl. xvi. fig. 1, 7.¢.) in the case of the young
of the Common Fowl and that of a Pigeon. This I can also confirm from my own

1 The italics are mine.

* In feathers of equal lengths for the two parts, such as in the Emu, it can be reliably ascertained only
when in situ. As asymmetrical structure consisting of two equivalent parts, it naturally follows that their
ventral or, more correctly designated, inner sides face each other, whilst the outer sides (dorsal for the main,
ventral for the accessory feather) are averted, irrespective of the convexity of their surfaces, which is a
concentric one for both.

VOL. XVI.—PART VIII. No. 3.—May, 1903. 3 F

364 MR. E. DEGEN ON ECDYSIS.

observation. This mode of a first acquisition of flight-feathers equally applies to
the rectrices.

The birds known as Nidifugea, like the Gallinw and most of the game-birds, acquire
their flight-feathers shortly after emerging from the egg. The young of the Argus
Pheasant is an instance in which flight-feathers make their appearance immediately
upon leaving the egg. But we have evidence of much earlier development of flight-
feathers than that mentioned above. ‘This is seen in the MWegapodes (and very probably
too amongst the Cracidw), whose young acquire their first set of remiges before! they
leave the egg. To this character the term of “ Ovifugw” might reasonably be given.
Whether or not this first plumo-pennaceous garb be pre- or post-incubate, matters
little ; it invariably is heralded in the Dasypedes by the adventitious plumage referred
to above as the truly embryonic one.

Text-fig. 2.

Dorsal view of the left-side wing of a young Parrakeet, showing the sessile filamentous plumes
of an adventitious plumage (neossoptiles) on the tips of the upper covert-feathers.

The function of the first set of flight-feathers with their principal coverts in the
fledgling being practically the same as that in the more matured individual, structurally
it is, nevertheless, inferior and more primitive in texture than that acquired by subse-
quent moults. The vanes of the feathers are generally broader, their tips more
rounded, the barbs and barbules present a looser union than those which eventually
replace them (see remarks made on this point by Brehm (7, 8), also Fatio (19), p. 254).
The body-feathers are similarly inferior in substance. Wittmer Stone (44), on pp. 115—
117, makes the following statement :—“ The remiges and rectrices of the first plumage
are usually the same as those of the adult, dut the body-feathers, while of the ordinary
structure, are much more plumulaceous+ than the covering of the adult “—deficient

' The ttalics are mine.

MR. E. DEGEN ON ECDYSIS. 365

not only in warmth of colour, but also in that lustre which imparts to them a finish
which makes them distinguishable even to the “touch alone” from the adult birds
(Altum (2), p. xxi). In a word, it is a provisional plumage.

Its duration, according to the quotations of the different writers, seems to vary for
the families, the genera, and also for the different species amongst the latter; but on
this head, owing to observations being frequently based on unreliable material, there
is great confusion.

According to Brehm (8) this first or fledgling-plumage is replaced in the genus Striz
by another of similar primitive quality—an observation which again called for a foot-
note from Dr. Cabanis (p. 344, /. ¢.), in which he gives expression of genuine surprise
in the following manner :—* Also zwei Dunenkleider!”1 &c., &c. “ Das ist in der
That sehr bemerkenswerth,” &c. But Brehm also showed that in the young of the
Owls the flight- and the tail-feathers, as well as the body-feathers, are shed in
the same season in which the bird was hatched, while in the Birds of Prey only
the body-feathers, excluding the remiges (and probably, too, the tectrices), are shed,
these latter being shed in their second autumn (Brehm (7), p. 196, & (8), p. 345).
This statement of Brehm was published only a year after the one in which Schlegel (40)
made the sweeping assertion that “the young birds moult for the first time in the
autumn of that year which follows the one in which they were born”. As the
aforesaid statement formed one of the fundamental tenets of Schlegel’s theory for
the alleged regeneration and revitalization of the bird’s feathers, it should scarcely be
surprising to find that no sooner had it been published than it drew a host of
contradictions, not only from Brehm, but also from the ablest observers amongst
ornithologists of the time. Amongst the latter was Homeyer (30a), who, after enume-
rating a considerable portion of the birds composing the list of genera and species claimed
by Schlegel for changing colour without moult, irrevocably proved this colour-change
with moult by emphasizing on p. 117 of the article, under the heading of “ allgemeine
Grundziige,” &c., on the first feather-change in the following conclusive words :—
“6, Alle kleineren und viele grossere junge Vogel mausern vollstdndiy im ersten
Herbste ihres Lebens.”

My own observation also disproves Schlegel’s statement in regard to this wholesale
assertion. To the list, therefore, of birds which undergo their first total moult in the
season in which they are reared, I can add also Gymnorhina tibicen, the species which
has been under my particular consideration and upon which I base this paper.

C. On “ Perennial Feathering.”

The manner in which the feathers on the wing of a fledgling bird are replaced
in subsequent changes is strikingly different from that in which they acquired them at

1 The italics are mine.

366 . Mk. E. DEGEN ON ECDYSIS.

first. It differs from it in shedding and eventually substituting the quills one by one,
sometimes two, even three or four at a time, occasionally but rarely more. Some
exceptions to this rule occur amongst the Chenomorphe (Schlegel (40), p. 20, /.¢., also
mentions the Anatine as exceptions), where the juvenile condition of shedding the
flight-feathers in greater numbers seems to occasionally recur with the periodical
moult. A case of such a seemingly abnormal character has been observed by Wiese,
on an old Crane (“ Beitrige zur Ornithologie Pommern’s,” J. f. O. 1855, iv. Heft,
No. 18, p.515). But, as has been pointed out by Gloger (26), p. 892, when remarking
on this case: “These birds have other means of locomotion than flight alone.” Quite
recently I had an opportunity of seeing a like condition in a Moorhen, kindly brought
to my notice by Mr. C. H. Grant in the Natural History Museum, who regarded the
occurrence as an exceptional one. The fishermen of the lake-entrances and
inlets on the south coast of Australia know this fact so well that in the case of
the Black Swans (Chenopis atrata), which are so numerous there, they frequently
take advantage of the temporary impediment to which the ‘* Moulter,” as the bird is
called at this time, is subjected, and amuse themselves by running it down in their
sailing-craft—a very exciting sport.

With regard to perennial moult, Schlegel (40) says, p. 20: ‘*6. The order in which
the flight-feathers are shed and replaced is that of bilateral symmetry.” Beyond this
general statement he has nothing further to say with regard to this important factor in
the feather-change. The observation that the flight-feathers were replaced in an
irregular sequence of their order, belongs to Gerbe (23). Although his observations
extended to a general comparison only between the Gallinw and Passeres, it is note-
worthy, nevertheless, to find how greatly he was struck by the peculiarity of order in
which the mouit proceeds on the forearm. This order he describes thus: “7°. A
Vavant-bras, la mue chez les Passereaux ne commence généralement que lorsque la
cinquiéme des primaires vient de tomber. Elle se manifest a la fois sur les deux
points eatrémes du cubitus et prend deux directions qui tendent Cune vers Vautre*: dun
cété elle se poursuit de la premiére de secondaires (cubitals) 1a la sixiéme inclusive-
ment; de l'autre de la neuvieme ou derniére a la septieme.”

For a considerable extension of our knowledge on this point we are indebted to the
researches made by Wittmer Stone (44), who regards the laws and principles which
govern ecdysis as, what he rightly terms for the bird, “ @ physiological necessity, common
to all”, But in attempting to deal with it in general as he has done, the ground
cannot be considered as sufficiently prepared until all the phases are known through
which the individual passes.

‘ The ttalics are mine

MR. E. DEGEN ON ECDYSIS. 367

VI.—‘ ORDERS OF THE MOULT”’ IN GYMNORHINA TIBICEN,

A. Flight-feathers or Penne alares = Remiges primores plus
Remiges cubitales (Sundevall).

The relative lengths of the flight-feathers on the manus are in the order below from
left (the longest) to right (the shortest), thus :—

7—6—8—5—9—4.— 8 —2—1—10.

The manner in which the remiges make their appearance is regulated by a definite order
in both portions of the wing. As might have been expected, the bilateral symmetry
assigned for the individual (cf. Schlegel, 40, p. 21) is not strictly observed. But there
is at no time any considerable departure from the broad principle. Besides this general
bilateral form of symmetry, there is one existing also for the two portions of each wing
inter se, viz. the hand and the forearm. It is present during the earliest stage of the
moult in the case of primaries I. and II. and secondaries VIII. and IX., the remiges
corresponding with each other for moulting first, as represented by specimen No. 1.

Diaer. A (stage a and 4). (Lettered on Plate XXXVI. a, b and d’, b! respectively.)

The fully adult specimen No. 1 (left and right wing) showed this earliest stage
remarkably well; younger ones not complying with the rule so exactly, as No. 2
proves, and also the following one, shot on the same date, mostly young birds.

Draer. B (stage ¢, d, e). (Plate XXXVI.)

The parti-lateral symmetry of the first stage becomes soon disturbed by the appear-
ance, in rapid succession, of primaries III., 1V., and V., lettered in the Table ¢, d,
and e respectively, these having no equivalent renewal on the cubitus'. Four specimens
show this arrangement remarkably well, of which No. 4, a very young male, does so in
part only. The diagram represents specimen No. 3.

Diaer. C (stage f'). (Plate XXXVI.)

The next stage, that of f{ which comprises the replacement of primary VL., is a
particularly interesting one, insomuch as it marks the restoration of the parti-lateral
symmetry by an almost simultaneous development of three secondary remiges. These
are cubital remiges I. or f’, X. or f", and VII. orf". Their synchronous appearance
therefore is a compensation for primaries! IIL., IV., and V. It is marked best in the
left wing of specimen No. 7, Plate XXXVI., as shown in the diagram C, which repre-
sents this third stage or that of fand its equivalents. This also explains the reason
why these remiges are equivaluated f', f", and f'" respectively (the dashes representing

1 The ztalics are mine.

368 MR. E. DEGEN ON ECDYSIS.

their sequence of growth), and not, as one would have expected c’, d', and ¢', were
they making their appearance in synchronism with c,d, and e. Four specimens show
this phase of moult, viz. Nos. 7 (diagr. C, Plate XX XVI.), 8, 9 (partially in arrear),
and 10 (see also Plate XXXVI, diagr. D), partially in advance of development. So
well, however, does the latter one (No. 10) mark this stage and also the following,
viz. that of g in its beginning, which latter is the moult of primary VII., that it has
been added also to the series of diagrams, in which it is marked D, as illustrating a
case of transition for the two stages.

Diaar. D, showing transition between stages f and g. (Plate XXXVI.)

This represents specimen No. 10, and referred to above. This individual is very
asymmetric in moult, both for bilateralism and left-sided development. It exhibits
the somewhat rare occurrence on its left-side cubitus of synchronously shedding no
less than three remiges: viz. X. belonging to stage f', II. stage g', and very prema-
turedly VI., as belonging to a much later stage, 7. e. that of k'. Its right Side fairly
agrees with the normal condition.

Diaer. E (stage g). (Plate XX XVII.)

Stage g, or the replacement of metacarpo-digital remex VII. and synchronous in
growth with cubital remex II. (g’) (as referred to for the last specimen, No. 10), is not
clearly defined in either of the five or six individuals which share this phase of the
moult. For instance, in No. 12 this phase is shown in the cubital portion only ;
while in its hand portion the changes are in progress only as far as remiges VI. on
both sides. Similarly No. 15 for its left side, while the right side of this specimen
shows stage g in a normal condition.

An otherwise clear case of this stage of development obtains for specimen No. 15;
but this individual, being a later acquisition than No. 14, which represents a typical
case of the next following phase, or that of 4, I have consequently not admitted to the
diagrams, because of the desirability for conforming to the order in the succession of
the dates as near as possible.

Specimen No. 11 therefore has been substituted to supply the present Diagr. E,
Plate XXXVII., as supplementing the part development of this stage of g, referred to
in the previous diagram D.

Diaer. G (stage h). (Plate XXXVIL.)

The next phase in the moult is that of metacarpo-digital remex VIII., or stage of h,
which appears in regular sequence in the numerical order of the feathering of the
hand portion. Corresponding in synchronous development on the cubitus with this
quill is remex III., lettered h’.

As mentioned above, specimen No. 14 shows this phase distinctly, though in its

MR. E. DEGEN ON ECDYSIS. 369

early growth. This is particularly the case for the primaries, on both sides, which are
just issuing; whilst cubital remiges III. have already attained about 4 of their
ultimate lengths. Being, however, developed quite symmetrically, the specimen was
better adapted for a concise diagrammatic representation of this stage than other and
later ones, which blend more or less with either the earlier stage of g or the later
one of 7.

Diaer. F (supplementing stages g and h). (Plate XX XVII.)

The specimen which supplies this diagram is No. 16. It is one showing the phases
of transition between g and h. This specimen repeats and completes the stage of g,
while that of h is developed in part. It therefore precedes for stage of development of
specimen No. 14, diagr. G, on the same Plate, although forming part of a complement
of specimens which were received at a later date.

Diaer. H (illustrating stage ¢ partially). (Plate XXXVIL.)

In specimen No. 17, which this diagram represents, we have an individual which
should mark the next phase in the moult of the primaries, namely that of metacarpo-
digital remex IX. or 7 if under normal conditions. But this individual being in arrear
of moult for the hand portions (metacarpo-digital remiges IX. being as yet undeveloped)
it merely shows this phase of renewal for their corresponding remiges IV. or 7’ on the
cubitus. It has been diagrammatized, nevertheless, for helping to complete the illus-
tration of this stage of development, which is one not very clearly accentuated in either
of the specimens which partake of it. For instance, Nos. 18 and 19 are considerably
in arrear of moult; the latter, however, is distinguished by showing stage 7 partially on
the cubitus. No. 20 agrees with No. 19.

Diaer. J (supplementing stage 7). (Plate XX XVIII.)

In specimen No. 21, which this diagram represents, we have a case in which the
conditions for stage i are reversed: since remex IX. is in full process of growth
in the hand portion of the left wing; whilst it has just issued on the right
wing, the side in which it is usually more in arrear than the other. The moult for
cubital remex IV. or 7’, the corresponding one for that of the hand portion, has not
yet set in for the right side. This specimen, then, together with that shown in
Diagr. H (the former one), supplement each other in the completion of stage ¢ and 7’
respectively.

No. 22, in arrear of moult, conforms to stage /, but is conspicuous as showing a case
of almost perfect bilateral symmetry. |

No. 23 is further in arrear, having reached stage g only.

370 MR. E. DEGEN ON ECDYSIS.

Dicer. K (stage of #). (Plate XXXVIII.)

In specimen No. 25 the successive growth of metacarpo-digital remex X. or
stage k, and the last to be replaced for this series, we possess a particularly
well-defined case of absolute bilateralism of symmetry. The development of this
flight-feather has reached exactly the same length on both sides. Its synchronous
equivalent on the cubitus, namely remex VI. or #', has also been developed in perfect
symmetry, having nearly obtained its full growth. The metacarpo-digital remiges IX.,
also symmetrically developed on both corresponding portions of the wings, are yet
incomplete, though porportionately further advanced than X., and beautifully show the
regular order of their successive growth. This particularly typical specimen deserves
special attention.

A glance at the diagram of this last specimen will at once disclose the fact that the
replacement of the flight-feathers, which at this stage is merely completed for the hand
portions, is incomplete for the cubitus, where a gap is left still for the filling in of
remex V., which is the last one to appear in this section of the wing. ‘The earlier
accomplishment of the moult of the flight-feathers belongs, therefore, to the hand
portion, both in its initiating as well as its concluding stages. ‘his is the case with
three specimens out of four which participate in this last phase. These are Nos. 24,
25, and 26 (left wing), and which have all been diagrammatized chiefly for showing the
growth of cubital remex V. in its earliest relationship to the others; and lastly, No. 27,
which also shows a further case of perfect bilateral symmetry. It has been found
necessary to give a diagram of No. 24, because it shows the final stage in filling up
the gap by cubital remex V. Again, this stage, having practically no synchronous
equivalent on the hand portion as above mentioned, required the application of the
additional letter /' to mark this supernumerary condition.

Diser. L (stage of 7’). (Plate XXXVIIL.)

This represents specimen No. 26, and shows this stage in its beginning, the secondary
remex V. being of equal development on both wings.

The growth of primary X. is nearly complete for the left wing; whilst its develop-
ment on the right side is considerably retarded.

Diaer. M (supplementing stage of /'). (Plate XX XVIII.)

As indicated above, specimen No. 24, though imperfect for the completion of the
moult on its hand portion, but otherwise very symmetrically developed, forms a case
for further progress in the final stage of 7’ or cubital remex V. It is curious to note
how early this specimen has reached this stage, being of February 18th, when com-
pared with 26th and 27th, which were both received a week later, namely March 4th.

As already stated, the specimens completing the List of Birds examined, which
were received as late as the end of April, had their moult positively completed,

EXPLANATION OF

to

ee

. The vertical lines form the divisions for the whole period of the moult for the remiges, consisting of

28 weeks.

The horizontal bars, situated between any multiple of vertical lines, represent the respective remiges, whose

ordinal number, in Roman figures, is placed in the lefthand-side column, as counted from the wrist-
joint.

. The letters to the right side of the table denote the order in which they moult, by plain letters, and

alphabetically arranged for the metacarpo-digital—with one or more dashes (thus, ', ”, ’) for the
cubital portion of the wing, and also in their synchronizing order of moult with that of the hand-portion.

The darts on the right side of these letters are indicative of the direction of their moult for the groups
of which these remiges form an integral part. (See also Plates.)

Top line: names of months for the period during which the perennial moult of the flight-feathers proceeds
in Gymnorhina tibicen.

. The numbers entered on the second line are the dates of those months on which the specimens were

received and examined.

. The cyphers on the third line, in addition to the number of weeks which each particular quill requires for

its development (collective time for the species) from its first appearance to its full growth, also serve for

comparing chronologically any two or more quills between the metacarpo-digital and the cubital portion
of the wing, or tinier se.

T'o face p. 370.

TABLE

1897

1896.

March

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February

January

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December

November

October

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Chart, setting out the Period of Growth, and Gisonology in the
Development of the Main Quills.

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MR. E. DEGEN ON ECDYSIS. 371

though in the case of Nos. 28 and 29 the cubital remiges IV. and V. were still
somewhat short of their ultimate lengths.

B. Remarks on the Period of Growth and the Development of the Remiges.

Although the actual time required for the production of each quill itself cannot be
followed with precision in the dead animal, neither is such the case with a bird in
captivity, owing to altered conditions. But this can, nevertheless, be estimated tolerably
well from a number of specimens which show a particular quill to be in moult within
a given stage ; and, further, with the aid of a quill just recently developed to full growth,
as is the case in the majority of individuals showing more than one quill in successive
stages of development at the time, and another one perhaps just emerging, when we
get a valuable means for obtaining, by differential inference, an approximate result for
the individual.

From the averages extracted for the period of growth for each quill, the result shows
that those of the earlier stages develop faster than those of the later ones, which take
somewhat longer to grow. The difference, however, is not considerable, and fluctuates
between seven and ten days respectively. The range of time for the moult of the
different remiges during a seasonal change can also be computed for the species as a
whole, and a chart (Table IL.), setting out the general result, having the additional
advantage of showing their synchronic movements, has been appended also at the end
of these remarks.

C. The “ Bastard Wing.” Alula or Ala spuria = Plume pollices.

In all robustly and normally developed individuals of this species I have never
failed in finding the regular number of penne, which constitute this series, to be less
than four. It is in weakly developed individuals only that their number is occasionally
reduced to three. In such cases it is invariably at the expense of the innermost, or
the first one if one regards them in the same light as the metacarpo-digital remiges.

Had there any additional proof been wanting on the remigial nature of these
feathers, apart from a previous observation of the most proximal ones being sand-
wiched in between an abortive upper and a homologous ventral covert, nothing could
have been more fortunate for dispelling the doubt as to their true value as flight-
feathers than that shown by their moult.

When I had received specimens representing the progressive stages of the moult
for a consecutive number of weeks without having met as yet with any evidence on
this point, I began to entertain serious misgivings of having missed what I then
considered to be one of the most desirable points in this investigation.

As these feathers, it seems but reasonable to assume, are not greatly exposed to
wear, it is at all times difficult, as I found, to distinguish between their old and
their new growths, unless one secures the bird during their actual renewal.

VOL. XvI.—ParT vill. No. 4.—May, 1903. 3@

pe Mk. E. DEGEN ON ECDYSIS.

It was a great satisfaction to me therefore when, on December 11th, I received the
first specimen of a young female, numbered 14, which showed evidence of the moult
for three out of the four feathers on both wings. A second bird, forming part of the
same weekly complement, and which had received the serial number 13 on account of
having been examined before the former, also a young female, exhibited no traces
of moult for this part. ‘This difference may be accounted for by the latter specimen
being more backward in moult than No. 14 as regards one or two of the metacarpo-
digital and one of the cubital remiges.

The next weekly instalment, consisting of four specimens, contributed nothing
further to this stage of the moult. Curiously enough, another young female, No. 19
of the series, supplied the desired evidence for the whole of this set of feathers in such
an excellent manner for both wings alike that nothing could be more perfect fora
demonstration of the graduated succession of their growth, as seen in text-fig. 3

>
from my drawing of its right wing.

Text-fig. 3.

4+

Ren WIS

Carpal covert. Alula of right wing.

Metacarpal.

Showing the successive stages of development of the quills composing the Alula,
from without inwards.

The figure shows the fourth longest and outermost feather, if not perfectly freed
at its base from the capsula, to have at least acquired its ultimate full length.
The next inner one, whose adhering capsule remains and encloses a greater amount
of the new growth in proportion to the former, shows it to be about } of its eventual
length. The third innermost, being remex II., and the next in rotation of development,
has attained one-half of its length; whilst remex I., or the innermost and last to appear,

(3%)
a)
1h)

MR. E. DEGEN ON ECDYSIS,

has only reached the stage of development of a pin-feather, whose extreme barbs have
just pierced the tip of its accompanying capsule. In text-fig. 3 these feathers are
marked respectively, remiges IV., III., IL, and I., in the order described above.

Another specimen received on the same date (January 16th) as the previous one, to
which I have given the serial number 20, also shows the whole of this set in full
process of moult on both sides of the wing, but is in a rather more advanced stage
throughout.

Two specimens, Nos. 21 and 22, dating from January 29th, out of the total comple-
. ment for that week, which also includes No. 23, also partake in this phase of the moult.
No. 22 is slightly belated if compared with No. 20, whose early-accomplished penne
pollices correspond with the moult of metacarpo-digital remiges V., VI., VII, and
VIII. respectively ; whilst in the case for the left side of No. 21, they correspond
with primaries VI., VII., VIII., and IX. The right side is later still, where the 4th
feather is the only one as yet replaced; this corresponds with metacarpo-digital
remex VII.

Specimen 22, for an old female, presents a case of later appearance still, and,
moreover, shows the additional anomaly of simultaneously producing (but symmetrically
for both sides) the fourth and the second quills, whereby it has missed the renewal of
the intervening third quill. The impending moult of this latter is indicated by its
point just showing above the epidermis on the right side only, thus, as it were, rapidly
remedying the deficiency. Seeing that this is the only specimen out of four quite
normally moulting individuals, this case can be little else than the result of a faulty
individual constitution.

In the remainder of the specimens received after this period, the moult of this series
of feathers was invariably accomplished. It, moreover, shows that their moult is
identical in period with that of certain primary remiges, and corresponds almost
exactly with the extreme digital ones by slightly fluctuating between metacarpo-
digitals VI. and X.

The relative position for the growth of these penne pollices to those primaries with
which they moult in synchronism, based upon the highest aggregates received for each
feather separately, will be found entered on Table VI., which is at the end of the
technical description dealing with the feather-tracts in general.

The moult of these penne is of ever so much greater importance than their purely
ordinal replacement when considered from the point of digital feathering as a whole.
Whether the origin be a doubtfully remigial! or an admittedly tectrical one only is of
no consequence in this place. At the most their metacarpo-digital value must remain
undisputed, since the principal satellites, as will be seen, also reflect the ordinal

‘ The similar absence of sedentary neossoptiles on the tips of the first set of these feathers, the same as in
the other remiges, ought, in my opinion, to be decisive on this point.
ia)
3G 2

y ON ECDYSIS.

DEGE

K.

MR.

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MR. E. DEGEN ON ECDYSIS. 375

sequence for renewal, as do the flight-feathers themselves, with the same constant
accuracy of recurrence in the species. As such, then, we have the astonishing fact
standing, that they moult (as may be seen from the drawing) i an opposite direction
to the metacarpo-digital remiges. ‘This is in no way an isolated occurrence, but a
condition which one finds twice repeated on the cubitus, and which, as I believe I am
justified in regarding, affords us the key to the original, if not pentadactyle, at least
tetradactyle feathering of some ancestral type of birds.

D. Extract from and Remarks on the Table of Percentages for the Deficiency
in the Power of Flight.

When consulting the foregoing Table (III.), it will be noticed that for both the lowest
and the highest percentages the figures are distributed fairly equally without having
any direct bearing upon either stage of moult, age, or sex of the individual. Thus we
get minima and maxiina at all times during the changes.

The lowest figures we get are as follows :—

Metacarpo-digitals. Cubitals.
ebtysicleeemeer i) sa) ieee lina (2G) “4 (21)
Richtside ea la ssew seeaanS) “2 (8)
Totals for left side. Totals for right side. Grand total.
2°2 (8) 31 (25) 3°0 (25)

The highest figures thus received are :—

Metacarpo-digitals. Cubitals.
Left side . . . . 24:2 (14) 22°9 (12)
Richtistden se esneee cose (4) 20°8 (16 & 17)
Totals for left side. Totals for right side. Grand total.
23'8 (10) 71 (4) 20°1 (10)

(The figures within the brackets indicate the number of the specimen.)

It will be seen that, while the greatest amount of feather-loss incurred at any time
during the moult occurs on the hand-portion of specimen No. i4 with 24:2 per cent.,
the cubital portion is only slightly behind this with 22:9 per cent., shown in,specimen
Now 12%

For the totals, the highest one obtained is in the case of the left-side wing with
23°8 per cent., aS against one of only 17:1 on the other side.

An analysis for the different portions of the two wings, however, gives the general

376 MR. E. DEGEN ON ECDYSIS.

result of an even balance for the specimens as a whole, as may be seen by the following

figures :—
Higher °/, losses.
. a : : 7 ry
Left side. Aight side. Equal °/, loss. Total.
Metacarpo-digitals. . . . 8 specimens. 10 specimens. 9 specimens. 27 specimens.
Gubitalsi- aan tien) tne LO . 10 5s 7 _ 27 -
Composite wing. . .. . Il 3 12 PH 4 > 27 Pe

Perfect symmetry is present only in four specimens ; these are Nos, 4, 14, 22, and 25.
For greatest differences of asymmetry amongst these specimens the numbers are dis-
tributed as follows :—

For the metacarpo-digitals, two out of ten specimens, namely, one each (for each
side of the wing). These are Nos. 9 and 24.

For the exbitals, one out of 15 (for the left side), This is No. 10.

These differences get considerably levelled in their aggregates, as may be seen from
the totals obtained between the left and the right wing of Nos. 8 and 10, which two
specimens show the amount of this difference to be one of 7 per cent. for each.

Finally, as indicated in the column of percentages of the total feather-loss for
both wings (see grand totals), this does not exceed $ of all the flight-feathers, as
specimen No. 10 shows, with the highest total of all, viz. 20°1 per cent.

E. The Wing-coverts. Tectrices prime serii s. majores.
1. Superiores.

The upper major coverts are usually the most prominent ones of the series which
accompany the flight-feathers, and to which they are more closely related than are
any of the remaining series. They also resemble flight-feathers entirely, both in
texture and development. When fully developed, their length on the manus is about
one-third part of each flight-feather in this species.

On the cubital portion these coverts are proportionately longer, covering about
one-half of their respective remiges. But whilst the latter maintain a nearly uniform
length as far as remex VII., from whence to the last or remex X. they rapidly decrease
in length, their upper major coverts, on the contrary, slightly increase in length in
the same direction, ¢. é. towards the upper arm.

In the flexion of the wing known as the carpal joint, the first covert belonging to
the hand and the first one belonging to the cubital portion, which are directly approxi-
mated here, are of nearly equal lengths, as are also their respective flight-feathers.

Metacarpo-digital portion.—The order in which the dorsal major coverts make their
appearance on the manus is precisely the same as that of the remiges, being one of
perfect synchronism both for growth as well as for the respective sequence of renewal.
I have never found any deviation from this principle in the normally developed

MR. E. DEGEN ON ECDYSIS. Sued

individuals which I have examined. Whenever I met with any exception it happened
only where the remex in moult had been accidentally retarded in growth. The latter
case can invariably be detected from the normal course of development which the
major covert pursues, provided that the anomaly has not been caused by external
injury.

Now and then the allied covert is shed a little in advance of its remex, but in the
majority of individuals it is shed simultaneously with it. Only in three cases did I
find the conditions reversed—that is, the remex preceding the principal dorsal covert
in moult by being shed first.

The rule therefore of the dorsal major coverts slightly preceding in moult their
respectively accompanying flight-feathers is a character inherent to the conditions
prevailing for the acquisition of the first or plumage of the fledgling bird.

This law being so uniformly carried out as regards the metacarpo-digital portion, a
few remarks, having reference to the alleged wndecem-pennate forms of Passerine birds
of Gadow (21), may be made here.

So long as it was taken for granted generally that the main covert directly asso-
ciated with a quill was the one which lies proximad to the latter, it follows that
Dr. Gadow was without question fully entitled to the conclusions he had then
arrived at in regard to the exact relationship of the terminal feathers. But, when
inquiring later into this matter (Degen (16), pp. x—xiii), I was able to show histo-
logically, as well as by means of the physiological conditions of moult (see also
figures 2 & 3, /. c.), that the conditions were invariably reversed, viz., that the major
coverts most intimately connected with the main quills were those which are iying distad
to the latter. ‘This naturally had the effect of leaving one feather less to be disposed
of, instead of the two supernumerary ones as in the case of Dr. Gadow (his alleged
11th quill and its corresponding covert), for a great number of genera and species of
Passeres; those with 9 and those with 10 primaries alike, including amongst the
latter also the species under special consideration. Dr. Gadow’s own words (pp. 659
& 660, /. c.) on this point are :—‘“ In some cases there might be some doubt whether
the little terminal feather in question is really a primary, but this can easily be
settled by the presence of the corresponding upper coverts. Moreover, there are many
cases in which the primary is still longer than its covert’. When the 10th or 11th
quill is much shortened, the corresponding lower covert is absent in the Passeres1. The
Alaudide prove that the 10th quill is capable of being shifted dorsalwards, so that
it becomes enclosed between the outer vane of the Ith primary and the 10th upper
covert, instead of being freely visible below and in front of the 9th primary ; when seen
from below, it is hidden by the outer vane of the 9th primary. ‘This shifting explains
the conditions which are the rule amongst the birds of Group D (p. 664, /. ¢.). The
Lith primary undergoes a similar dislocation in a more marked degree”? *.

1 These ttalies are mine.

378 MR. E. DEGEN ON ECDYSIS.

In agreement, then, with the issue of flight-feathers on the hand-portion of the
wing, if the terminal feather in question were a primary, it follows that, like the
remainder, it should moult in turn, after the renewal of remex X. Such, however,
is not the case, as specimen No, 24—the only one showing this stage—proves. On
the right wing of the latter this feather has been renewed, whilst remex X. is still the
old one, and its own major covert, recently shed, lying distad to it as previously
explained, is just emerging, showing the apex of the new growth, anticipatory of
the shedding of remex X. itself. This particular stage of moult is slightly in
arrear on the left-side wing of this specimen, the general conditions being otherwise
quite similar. Here, however, instead of this alleged primary being renewed already
(it proved to be the old one yet by accidentally dropping out upon being touched, which
is a sure sign of its impending renewal) before the covert belonging to primary X., the
old one was not yet shed. ‘here is consequently a strong probability in favour of this
terminal feather being the major covert belonging to the ventral series (median ?) of the
suppressed remex XI. (remicle), by its moulting in advance of the remiges, a condition
which does apply to the ventral series, as we shall see further on when considering
their moult.

Cubital Portion.—The conditions under which these major coverts issue differ so
widely from those previously dealt with that they are well deserving of more careful
consideration.

Whilst there is the same unalterable mode of renewal retained for this series of
feathers on the manus throughout all subsequent periods of general moult by
repeating the first mode of acquisition, such is not the case for the major coverts of
the cubital portion.

Here we are confronted by the occurrence of several transitory stages between birds
of the first season and those of subsequent ages. Broadly speaking, there are three
different stages conspicuous !, which may be further subdivided as follows :—

Stace I. Condition of renewal for Bird of second season.
(a) Growth of major coverts (0) 1-7 simultaneous (() representing carpal covert).
(4) Growth of coverts 8-10 consecutive in the order of these numerals forming
Group l.

Following upon the mode of the renewal of the first season’s bird or fledgling stage,
which consisted of the simultaneous growth of the whole series of these coverts from
1-10, the mode of the first perennial moult differs by coverts 8, 9, 10 constituting
themselves into a definite group. Specimen No. 4 represents this first stage in a
striking manner on both wings (cf. fig. 1, Table IV.). The major coverts 8-10 are
differentiated from those of 1-7, which are all of uniform length in development, by

1 This refers to renewal only, and does not include the initial stage of feathering of the fledgling.

MR. E. DEGEN ON ECDYSIS., 379

being graduated in length of growth, a condition which corresponds with that of their
corresponding flight-feathers. This first grouping arrangement is well defined in
all the specimens of birds of the second season and upwards.

Stace Il. Group-moulting of various degrees of development.

1. Consisting of formation of previous Group (1.) with the remainder of coverts (0-7)
renewing from 7—1 (0) in outward direction. (See Table IV. fig. 1.)

2. Consists of coverts (0) 1-4, or Group II., renewing in an inward direction. All
the feathers of this second group are either equal in length or partly in graduated
condition of development. In the latter case they are supplied from without
inwards. (See Table IV. fig. 2.)

3. Consists of coverts 5-7, forming Group III. The feathers belonging to this
third group at this stage appear still simultaneously (cf. diagr. Table IV. fig. 3).
(Feathers in nascent condition of development.)

The first degree is common to all individuals, both young and old, and particularly
clearly defined for Group I. in specimen No. 4, as quoted already. (Table IV. fig. 1.)

The second degree is represented by specimen No. 2, more particularly so for the
right wing; by No. 6, left side; and No. 14 on both sides. (Cf. Table IV. figs. 2, 3.)

The third degree of this stage of moult, represented in diagram by specimen No. 19
(see Table IV. fig. 3), occurs on right side of specimen No. 5, both sides of Nos. 9
and 15, and on the right-side wing of No. 23. In the latter specimen we have a
remarkable combination of two cases of transition from one stage to another by its
left-side wing already adopting the more advanced condition of the fully adult
individuals of the last, or

Sage III. In which the main dorsal coverts follow the same perfected group-arrange-
ment of moulting in synchronism and in the identical order of appearance as their
respective remiges, ‘This condition is shown in the diagrams by specimen No. 24.
(See Table IV. fig. 4.)

This last stage is achieved only by the oldest individuals, and is attained by the
metamorphic steps of consecutive moults, commencing with the young and finishing
with the fully matured bird.

Further examples of this latter kind are to be seen on the left side of No. 21, an
adult male, in which the carpals and coverts 1 and 2 have been completed, as have
their respective remiges. Coverts 3 and 4 are equally incomplete as are these remiges.
This condition obtains independently and in addition to the renewal of coverts 8-10 as
a first definite group. On the left side of No. 23, a young female, we have, besides the
same independent final formation of Group I., the incomplete growth of coverts 3
and 4, which, though slightly in advance of growth as compared with the other side, is
proportionate to that of their equally incomplete remiges; whilst at this stage,

VOL. XVI.—PART Vill. No. 5.—May, 1903. Rin

580 MR. E. DEGEN ON ECDYSIS.

covert 7, which is in a nascent condition of growth, foreshadows the impending moult
of the remex with which it is associated. Coverts 5 and 6 appear to be the old
feathers as yet unaffected by moult.

There is no necessity to dwell in detail upon all the remaining old individuals, as they
obey the law stated in the cases quoted above, which is that of perfected group-moulting
as it applies to the flight-feathers which occupy the cubital portion of the wing.

Unlike the well-defined synchronism with which the upper major coyerts keep pace
with the remiges of the hand-portion, there exists a marked contrast in the way they
make their appearance on the forearm, inasmuch as they follow the general tendency
for moulting in advance of their allied remiges, irrespective of age. Through some
inexplicable agency, and for a much longer period—in fact, through nearly every moult
during the bird’s life—they adhere to the more primitive conditions of the first, or
fledgling livery. ‘The only admissible inference to be drawn from this fact must be one
largely in favour of this early endowment of wing-feathers to be a secondary provision
and of ontogenetic origin.

2. Inferiores.

Metacarpo-digital Portion—The difficulties in following up the order of renewal
which this series adopts are greater than those attending the researches into the
previously considered upper series. The chief one arises from the circumstance
of the more protected position which they occupy on the inner side of the wing, and in
which they suffer less from the effects of wear than feathers which are constantly
exposed. Hence the greater difficulty for determining between old and new growth
in fully developed feathers. It is only when particles of the capsule within which they
were formed are still adhering to the recently renewed feather that the fact can be
ascertained, or where the renewal consists of feathers in a state of nascent growth.
We cannot expect to meet with the latter phase in any considerable number of
individuals alike, and therefore I could find positive evidence on this head only in
9 birds out of 25 specimens after deducting Nos. 26-52, which are in a state of actually
complete renewal or nearly so.

With one exception only, viz., that of the old female No. 22, these specimens are
characterized by almost perfect bilateralism of symmetry on the two wings as regards
the hand-portion for the moult of this series of coverts. ‘These are Nos. 1, 14, 16, 17,
18,19, 20, 22,24, and 25. According to their ages and sexes they range as follows :—

Totals.
Males. Old: Nos. 1, 17, 18, 20, 24, 25 . 6
55 Young: No. 16 1
Females. Old: No. 22 : 1
y, Young: Nos. 14, 19 2

By leaving out fram immediate consideration the old male No. 1, obtained in the

MR. E. DEGEN ON ECDYSIS. 381

first batch of Nov. 5, with Nos. 2 and 3, it is noticeable that, of the birds received
before the dates of December 11 and 19, which are represented by specimens Nos. 14
and 16 respectively, none exhibit any signs of mouit having set in for this row of
coverts. Nearly all of these represent young birds, and there is good reason for
assuming that Nos. 9 and 10 are not fully adult either, as I considered them to be at
that time, judging from external appearance alone. It is therefore evident that
the renewal of this row amongst younger birds does not set in until about towards the
middle of the period of perennial moult.

The renewal of this series takes place in the same order as that of their respective
remiges and upper major coverts, which commences with the innermost and concludes
with the 10th or outermost, though differing in regard to chronicism according to age.

In the youngest birds no lower major covert is renewed until nearly six to eight
flight-feathers have been formed. From this retarded appearance every subsequent
moult recovers one or two places from the flight-feathers which moult in advance of
them, till, finally, in the perfectly adult stage, their renewal synchronizes absolutely
with that of the flight-feather with which they are associated.

The most instructive specimen on the list, representing this culminating phase, is
that of the old male No. 1 (see Table IV. fig. 6), which is also one of the earliest for
beginning the moult for this series of feathers. Its remiges I. and II., together with
their dorsal major coverts, which under all circumstances are the earliest to moult, are
simultaneously accompanied in moult by their respective ventral major coverts.
Indeed, on its left side, the inferior covert 3 is slightly in advance for making its
appearance of the old remex III., which, having just been shed off, shows no sign yet
of the new-growth quill. The same condition obtains for the remiges on the right
side of the wing, the inferior coverts 1 and 2 being synchronous with the dorsal ones,
which are being renewed also at this stage.

The adult male No. 25 is similarly characteristic for almost perfect synchronism,
though No. 24, an old male too, of which a diagram has been appended (Table IV.
fig. 4), represents one of the later stages of transition from the juvenile to the fully
adult phase of this row in relation to the flight-feathers. Both these specimens were
procured towards the end of the moulting-season, as their numbering shows, and
accordingly were in a much more advanced condition of the moult.

The remaining specimens, Nos. 17-20, represent every conceivable transitory phase
of retardation from their remiges by a steady progression for each moult of one ventral
major covert, from their original arrear of 8 (well instanced by specimen No. 18,
see diagr. Table IV. fig. 5) down to the case of absolutely simultaneous movement so
characteristic of adult birds, as explained above; this is continued through every
subsequent moult of the bird’s life.

The diagrams on Table IV. (major coverts) for specimens Nos. 18 (fig. 5), 14 (fig. 2),
19 (fig. 3), 1 (fig. 6), and 24 (fig. 4) illustrate some of these transitory stages.

3 H2

o3
2)

MR. E. DEGEN ON ECDYSIS.

bo

Cubital Portion.—This row of covert-feathers being suppressed in all the Passerine
birds, no positive information is available through this species for their behaviour
under conditions of moult.

A provisional examination of a diastatavic species (Platycercus eximius) shows
that there is no material deviation from the moult of their dorsal congeners as regards
synchronism with their remiges, excepting perhaps that they exhibit a tendency to moult
somewhat earlier than the latter and also adhere to the juvenile mode of simultaneous
replacement through more than one perennial change.

Tectrices secundee serii or Tectrices mediz.
1. Superiores.

Metacarpo-digital Portion.—In striking contrast to the order of the moult which
is adopted by the first series of satellites in relation to the remiges, stands that of the
second series, or the medians.

In the former, as we have seen, it consisted in a rhythmical accompaniment to their
remiges in the order of the growth of the latter. Not so for the dorsal median
coverts. Their renewal proceeds from two separate points on this portion of the wing.

The first of these two points, the earlier one at which moult sets in, is identical
with remex I. and its upper major covert. Its moult, however, does not synchronize
with these, because the earliest signs of moult of median coverts do not appear until
after the renewal of from 4—5 remiges with their principal satellites has taken place.

The second point at which moult sets in on the manus coincides with remex VIL.,
and proceeds in the same outward direction as does that from the proximal centre.

This different mode of renewal therefore bisects the hand-portion into two areas:
a first or proximal one comprising median coverts 1-6, and a second or distad section
made up by coverts 7-10. In birds at the beginning of the moult, and in which not
more than from 2—4 remiges are in process of renewal, as yet no medians make their
appearance.

The earliest specimen on the list in which the first and innermost of median
coverts is being formed is No. 3 on its right-side wing, which has reached the stage
of e (see also Diagr. B, Plate XXXVI., right side), or the moult of remex V.
The next specimen is No. 6, on the right side, too, of which median coverts 1
and 2 are in course of formation. Its stage of development for remiges is the
same as that of the previous specimen, viz. that of remex V., which denotes a
slightly more advanced condition here. ‘This specimen, moreover, has reached a more
advanced condition on its left side, where median covert 3 is being renewed also.
The renewal of 3 median coverts, however, generally coincides with that of remex VL.,
which is the more normal course which these coverts pursue. ‘This is well defined on
the right side of No. 9.

- Trans, Zoo, Soc., Vor, XVI.] [To face p. 382.

¥

EXPLANATION OF TABLE IV. —

The letters M.C.D. or C., placed above each diagram, signify Metacarpo-digitals or Cubitals.

‘The Roman cyphers, from I. to X., above the symbols Q © Ke. of figure 1, denote the numerical order of

the remiges and the major coverts, with which they are allied, and apply also to the other diagrams beneath.

The darts placed over or below any sub-series of major coverts point in the direction of their respective

sequence of moult.

The spherical symbols (and further explained on table itself) represent a theoretical cross-section through

the projected quills and coverts for which they stand, made longitudinally the whole length of the posterior

margin of the extended wing, or portion of it, as in the case of figs. 5 & 6.

Fig.

1. Showing Group-moulting for the upper major coverts VIII.—X. on the eubitus, and the simultaneous
appearance for I.—VII. im relation to their remiges under moult (Degree 1). Also showing the
relative movement of the remiges and the major coverts for the hand-portion.

. 2, Shows upper cubital major coverts I—LY. inclusive of carpal covert, forming Group JI. by moulting in

an inward direction, or one opposed to the stage for the same sub-series, illustrated in specimen
represented by fig. 1. It further shows the first stage of moult in relationship to the remiges of the
inferior major coverts for the hand-portion (2nd degree).

. 3. Shows the 3rd degree, or that of cubital major coverts V.—VII., constituting Group III., its integers

as yet appearing simultaneously. It also shows the more adyanced condition of moult for the
progressive movement of the ventral major coverts on the hand-portion of the wing.

. 4, Shows the final stage of moult in their relationship to each other of the remiges and the major coverts,

both upper and lower, in synchronous Group-arrangement for the cubitus, and in regular sequence
outwards for the metacarpo-digital portion, a mode which is adopted only by the fully adult
bird.

. 5. Shows the initial stage in the replacement of the inferior major coverts for the hand-portion.
. 6. Represents a similar stage, though slightly in advance of that seen in fig. 5.

M.C.D
; XRWWWUV VO cer os
T.maj-sup. 0 O OCO0 08 eG BOO.
Remigeess OQOOOOO@OO@ OOc
2Us SAN Pete) (Oh) (0) 6) HO) 1) 10) ©)

Stage II

M.C.D.

Group I

. ——

T.maj.sup.. © O @G@O@OGOOOBAOAD OD

Remigs OSOQOQOOOOO®D OG:

T.maj.inf CO OO0O0O080880 ® ar:

M.C.D.
Grou;
Clin
T.maj.su. oO @@2OOOODOHODOA®D

Remigees O)V@OOOO000O OO

T.maj.inf oO OO O@@@ 90 ® =

Stage Ill
M.C.D.

Gics
T.maj.su. 0o@ OO OODMDOCOHOO®”

Remigs ©M@Q@OOOOOOOO OO

T.maj.inf oO 0 @ @ @ © © @ @ aio

E. Degen, del.

Diagt

TABLE IV. To face p. 382.

Stagel
} Degree I.
M.C.D. c.
Groupl. d Mon
XRWVWUVVOLIicItnmwvVuVMwMox Fig.l. xX KWUWVVOonr Fig. 5.
T.maj-8up- oF OO00@e@ 8809000000880 T. maj.sup. 0 OO e@ 8 COC 8 ©
Remigs OQ) OOOO @@O8 OOO OOOC@@O*ree Ne & Remiges OOO @@OOOO® Svec. Ae: 18.
MEN HO QOOOOOVQGQ = s=> === === u TmjimtoOoo00000e8 JY
Stage I
MCD. Cosene 2.
eorouell M.C.D.
peee Sroupl Wig. 2. Fig. 6.
T. maj. sup. ecOeeeeneecoesevd O000069 T. maj.sup. 0 OC O0O00008®8
Remigs OSC OOSOSSOSOG OOQOOCODOOO Sree. No. 14. Remiges O QOQOOOO0C@® Spec. No.1
T.maj.in. oO O0O00@@ee@@ —— —-—~————-— TENS? T. maj.in. oO O00008 08 ad.é
McD c, Degrees.
sie G I Grovpl EXPLANATION OF THE SYMBOLS USED
Groupie Group ll Grou mig yc: IN TABLES IV&V.
. maj. up. 00 @ 0 O00COKOCHTODOX00800 ame Oe
quills and cover! us
Remiges 0 @OOOOOOOO ©00 0008 6O6C*r«. ane: 19.
HEB 0) OOO OO OQ === === aa = = New growth oF quills and coverts @Mo
Shedoff oo" » = mn
Part grown” 4 mow » @e
Stage lll Nascent » » 7 ” ~ @©o
MCD e Absentrow* 1 6» Fu
cc. Fig, 4. keh 3
aitiaiveust ores terarovevetexesevetersverererercrero € Coverts not under consideration ++
Remiges 0OO@OOOGOOD DOOD OOOOODOO spec. No. 24. Carpal coverts » Cc
T.maj.in. 0 OO0@@@@88@8 —————~-—~—-—-— ad.é
Bale & Danielsson, Lid.
BuDeer aa

Diagrams illustrating the movement under conditions of Moult
of both the Dorsal and the Ventral Major Coverts.

e 0

nA 2-2 2 & eee “eo @ ies in
308 20000.) Sian
; i 2. ; ==

we

ty 4 tou e ee re ae

Leon: YSeSaeaaqareao Py ni ig
ee SF eee ,

MR. E. DEGEN ON ECDYSIS. 383

The renewal of median covert 4, which is the next stage, as a rule corresponds with
that of remiges VI. and VII. To this condition, specimens Nos. 7 (right side),
10 (both sides), 11 (both sides), and also 15 testify very clearly.

At this stage the 5th median covert is frequently shed also, preparatory for its
speedy replacement, though in the majority of cases its moult corresponds with that
of primary VII., as does also median covert 6, whose moult rapidly follows that of the
5th of this series.

The morphological features for the coverts of the outer section, or distad area, are as
follows :—Dorsal median-covert 7 is renewed when the synonymous coverts 2 and 3 of
the inner section are formed—that is to say, in advance by one place of remiges V.
and VI. under moult (see diagr. Table V. fig. 1, referring to right side of specimen
No. 5). Synchronous with the formation of medians 1-4, the 8th also follows on in
rapid succession to the 7th. ‘This is well marked in specimens Nos. 7 (Table V. fig. 2
of diagr.) and 10 (both on right side). At the time of the formation of medians 5
and 6, the last two to moult of the proximal area, the 9th and the 10th or last
coverts of the distal area are also developed in rapid succession of each other. This
phase corresponds with that constituting the renewal of remex VIII.

In this manner, then, the moult of the medians forming the outer section is invariably
accomplished considerably in advance of their corresponding remiges VIII., IX.,
and X. ‘This is particularly noticeable in those specimens which partake of the later
stages of the perennial moult. These are Nos. 15-24, but especially is this the case
in No. 11 with its 5th covert just shed, and which, by still retaining the old covert 6
on the right, also shows coverts 7, 8, 9, and 10 in a state of complete renewal. This
typical case for the relative position of the moult of these coverts is seen in the
diagrams of Table V. specimen No. 7 (fig. 2) and No. 11 (fig. 3).

In birds of the season, however, the mode of renewal for the feathers of this series
is a simultaneous one still, the same as it is for the fledgling. This is seen in Nos. 2, 12,
and 14—birds which are undergoing their first autumn moult in the season in which they
were hatched. Specimen No. 12 in Table V. fig. 4 shows this particular condition.

Cubital Portion —The median coverts of this portion of the wing evince a strong
tendency not only for keeping pace with the moult of their respective remiges, but
actually preceding them, though not to such an extent as in the case of the major
coverts, of which latter they are, therefore, in arrear. ‘This is not only noticeable in
the case of the young individuals to which the embryonic condition for simultaneous
moulting applies, analogous to that of the major coverts, but a similarly accelerated
appearance of this series is seen to take place when the series is broken up, in order
to moult in groups, which is the ultimate adoption of renewal in the mature bird.
The transition from the former to the latter is effected by various intermediary
stages, which lead up to the same grouping-system as that of the remiges, viz. their
subsequent alternate direction of moult.

O84 MR. E. DEGEN ON ECDYSIS.

In the majority of the specimens the growth of these coverts proceeds in a fairly
symmetrical manner from both wings for either of the two systems of moult.
It, however, happens frequently, notably in the younger birds, that while the juvenile
mode is prevailing still on the one wing, the other wing may have already adopted a
stage of the later conditions.

Instances of perfect symmetry for the earlier stage of simultaneous development of
the series are Nos. 5, 12, and 15, which are all young birds; while a case of dualism
of development occurs, amongst others,in No. 13. In this latter specimen the wing of
the left-side is still following the early principle of simultaneous replacement ; it is
marked in this case by uniformity in length of all its coverts which constitute this
co-series; whereas on the right side, while still repeating the early mode on the
proximal portion of the cubitus from the 5th covert to the 10th (including a slight
modification of the 8th), the mode of the first definite formation for moulting in groups
has taken place on its distal part for coverts 1-4. This is shown by the diminishing
lengths in development of these coverts in their inward numerical order.

In reference to the modification of covert 8, as alluded to above, it is not a little
curious to find this covert to be the only one in a nascent state of growth amongst
those from 6-10, which are all about half-grown. Herein, then, we have an early
indication of plainly denoting the initial point in the ultimate formation of the first
group, which comprises coverts 8, 9, and 10. ‘This arrangement corresponds exactly
with that of the issue of the remiges and the main coverts in this place which have
preceded them in development.

Illustrations of perfect conditions for the group-moulting are Nos. 5 (left side),
11 (both sides), 15 (right side), 16 (right side), and probably all the remainder of
adults in which the moult of this co-series had been positively completed at the time
of their reception.

2. Inferiores.

Metacarpo-digital Portion —Quite distinct from the mode of renewal by means of
two separate sections of their dorsal congeners at a comparatively immature age,
the set of coverts under consideration here apparently follows the rule which
applies to the remiges and the main coverts of the young individual undergoing its
first autumn moult, viz. in the ordinal appearance of the feathers from 1-10.

The main cause for this apparent} difference lies in the fact that they begin to moult
later than their companion coverts of the dorsal series; but this is a delusion only.
It is not until from three to four of the latter have emerged and are fairly developed
that the first ventral median begins to replace its old feather. The others follow suit
in rapid succession, completing the inner section with the 6th, and so reach the 7th
covert or first of the outer section at about the same time as this latter emerges from
the skin. This arrangement gives it the appearance of a continuous growth for the
whole series, and therefore produces the delusion referred to before.

MR. E. DEGEN ON ECDYSIS. 385

Fortunately, among the specimens procured to supply data for the various stages,
No. 15 provides us with the desired information on the subject, where medew
inferiores 1, 2, and 3 of the inner area, and 7, 8, 9, and 10, belonging to the outer
one, are in course of renewal. That it is not a merely accidental circumstance, but
a reliable case, is further evidenced by the perfect symmetry of the occurrence on
both wings.

The relative position for the renewal of the ventral series in the Juv. ¢ , specimen 15,
to their dorsal congeners (see diagram of Table V. fig. 5) can be adequately formu-
lated thus :—

Metacarpo-digital Portion.

Left wing. Right wing.
Distal area. Proximal area. Proximal area. Distal area.
aT = i i Sy
Dorsal series . . . 10,9, 8, 7, ——4, 3, 2, 1 1, 2, 3, (4), (5), —7, 8, 9, 10
Ventral series. . . 10,9, 8, 7, ——— 3,2,1 Ny By Bi, Tg eh oy LW

The symbol o, placed above figures 4 and 5 of the coverts of the dorsal series of
the right side, denotes that these feathers were recently shed, thus showing the relative
movement for the different constituents of this row to be in nearly perfect synchronism
within the two areas; whereas for the left wing the 4th covert of the dorsal row, having
been replaced already, constitutes a case of retardation for the proximal area, the old
covert 5 being still retained.

However, individuals older by a season or two acquire perfect conditions of
synchronism for the dorsal and ventral rows within the same area, and a highly
instructive example of this is seen in the old male No. 10 (see also Table V. fig. 6),
which, moreover, shows the connection of the moult between the inner and the outer
area for the ventral medians, as below :—

Metacarpo-digital Portion.

Left wing. Right wing.
Distal area, Proximal area. Proximal area. Distal area.
a s Wier is ea if NS SN aN
Dorsal series. . . ——9Y, 8, 7, - (4), 3, 2,1 1, 2, 3, 4, ——— 7, 8, ——
Ventral series . . ——— (8), 7, (6), 5, 4, 3,2, 1 1, 2, 3, 4, 5, 7,8, —
> “@ °

It may be seen from the above formula that there is a slight overbalance of
synchronism in favour of the first division for the ventra/s in the shape of covert 5 on
the right side, and, in addition to this covert 5, on the left by the 6th covert being
shed preparatory to its immediate renewal. ‘This sectional synchronism can be studied
only on those few specimens which represent individuals of middle age, combining
with the latter requisite that also of this particular phase of the perennial moult.
In the specimens procured at a later period, the moult of this series is invariably
completed throughout.

386 MR. E. DEGEN ON ECDYSIS.

During the first total feather-change in the young bird, and to a great extent also
in that of the following season, all the feathers constituting this series make their
appearance simultaneously and parallel with the dorsal row of medians 1-10, without
the ultimate division into the metacarpal and the digital area, which is so character-
istic for subsequent moults. In this case, however, the synchronous development
with their equivalents of the dorsal series is a perfect one in their entirety. Partly in
the second, but wholly so in the third season, the transitory step from the one mode
to the other is effected by an intermediary stage. This consists in the inferior row
moulting in arrear of the dorsal one still, while yet adhering to the non-deciduous form
of renewal by means of a gradual supply of the feathers which begins with covert 1
(the innermost) and ends with 10 (the outermost). The dorsal row has meanwhile
already acquired, either on one side only or symmetrically from both wings, the
perennial or deciduous style above mentioned of the areal form of moult.

Nos. 7, 8, 11, 12 (see also diagrams for these, Table V. figs. 3 & 4), and also 13
are examples of specimens of either one or the other of these transitory cases. The
fully adult mode of moult, in which the ventral equivalents are renewed in absolute
synchronism with the dorsals, is reached only when the bird attains the positively
adult stage, and not before the 4th annual moult.

An approximate key to the various phases of the relative development between the
dorsal and ventral rows is appended at the close of the description for the whole
of these series (see p. 390).

Cubital Portion.—Bilateral symmetry, as we have seen it to exist mainly for the
hand-portion of the wing, is not nearly so pronounced a feature on the forearm for
this row of feathers. Out of 10 specimens showing this phase of the moult there are
3 which show cases of asymmetry in the corresponding portions of the two wings,
as the following analysis of these specimens shows :—

Symmetrical Development.

Males. Old: Nos. 17,20, 24,25 . 2. . . 4

5 MoS? =g§ 6 GO 0 6 o ob oOo OS

Females Old) tity cana acti oe ek ee

a Noung!) Nos, 14 ro 23 ert 3
otal ey — 7

Asymmetrical Development.

Males) s VOlA Noses yarn. 1
a Young: No.4. Gi 4c Glare 1
HemalesOldia isa 2 et
5) Young: No, 12 ys 1
Total —

Grandtotal . . . 10

[Lo face p. 386.

EXPLANATION OF TABLE V.

Fig.

Fig.

“J

T’. med. sup. = Tectrices medize superiores.
T. med. inf. = Tectrices medi inferiores.

Cyphers, symbols, and other abbreviations similar fo those used in able IV.

. Metacarpo-digital portion of right-side wing, showing the moult of medians I. and II., and the first

to appear of the proximal section. Also median VII., the first covert of the distal section.

No inferior medians in moult at this stage.

. Metacarpo-digital portion of right-side wing, showing the more advanced condition of four medians

belonging to the proximal section in moult, and two, medians VII. and VIII., on distal section.
Inferior medians I., I., and III. in moult also at this stage.

. Metacarpo-digital portion of right-side wing, showing dorsal median V. of proximal section as the

next in turn, shed off, preparatory for its replacement by new feather.
All the coverts of this series belonging to the outer section are replaced, also the whole series of
the ventral or inferior medians.
Metacarpo-digital portion of right-side wing, showing the renewal of the dorsal medians in regular
sequence of their ordinal numbers, irrespective of the two sections, and a typical instance of the

perennial moult of a first season’s bird.

. Metacarpo-digital portion of left- and right-side wing.

In this the sub-serial renewal for the two sections may be seen; both for their chronicism
between tne dorsal and the ventral series of medians, as it takes place in a younger individual.
Left- and right-side metacarpo-digital portions of the wing, also showing the chronological renewal of
these series in the case of the fully adult individual.

. Cubital portion of the right-side wing.

Principally shows the mode of renewal for the inferior medians in the very young bird in their
consecutive order for the whole series towards the wrist-joint from X.—I.

. Cubital portion of right-side wing, by specimen showing the typical condition of the moult of the

dorsal medians in advance of the remiges.
Also showing first signs of Group-moulting for the inferior row, in which coyerts I. and II.
belonging to Group II. moult in opposite or inward direction.

. Cubital portion of right-side wing, showing more advanced condition of previous diagram by 4 inferior

medians being in progressive stages of growth, also in inward direction of moult; while those of
group I., or medians X., 1X., & VIIL., are as yet adhering to the conditions of the moult of the

fledgling bird, 2. e. by moulting in an outward direction.

10. Cubital portion of the left wing.

This is an example of the final phase in the replacement of the inferior median coverts, and shows
the ultimate grouping-arrangement with directions of moult—inwards for Groups I. & II., outwards
for the middle or Group III.

I aN AE ANE
e)

VU WV x xX Fi
T. med. sup. ® @ O oO ® (Oy

Vv
e) e)
Maj. Coverts ap oe aR qe oP oP AP ae Sp ar Right Sic
Remigs MOQ QOQOBWCOOO° . Spec 2
Maj. Coverts +4 +4++4+++4+++4+ + +4
Tamedvinf. © © 0 0 0 © .0 6 © ©
F:
T.med.sup. ® 09 @®@®OO0O@®MO90
Maj. Coverts + + +++4++++4++ + ’ }
Right Sic

Remiges ()@ O@O ODOOO° Spec. N

Maj. Covertg +4 4+44+4+44 4 4
T.med.inf © ® @®O OO0O0000

T. med. sup. © © ®@ © © O © © @ @ EAM
WiajeCovertsect st ate apostate ate te) t=
2 aos, Right Si
Remigss @@ OOOO 2000 Sn a
Maj.Coverts + ++ +++ +444
T med inf © ® ®8O@OOOO Oda
Fi,
T. med. sup ®9@ O®D®ODdDO*GMOO
INN, COUGHS 4p ar SP ar SP ar ar arp SP oP
: 4 \ Right Sic
remiss @O O@ODOOC 0 Bebe Si
Maj. Coverts + + ++ +4++4++4 4 4
T med. inf. ®@®MO ®@OoOd00d0da

Various phases from the Moult of the M
Coverts on Metacarpo-Digital Portion of |

Met,

distal ar

T. med. sup. @ © @

Maj. Coverts + + +4

Fig. 5. Remiges ® (x) @
Maj. Coverts + 4 4

T. med. inf. 89 ® ®

T. med. sup. 0 @M ©

Maj. Coverts + + +

Fig. 6. Remiges ® (0x) (am)

Maj. Coverts + 4 +

T, med. inf. O O
E. Degen, del, L
Diagrams explaining
Median Coverts fi

ae
Naage

11 W@W Y Ww wvi K x
T.med.sup ©®@ 00008000

penbcelen oe tata ste memes itis sta Rien Sid enWine er

Remiges @@@OWSOOOS s
Maj. Coverts ++ ++++++ + +4
T.medinf0o0O 00000000

Fig. 1.

Spec No. 5. juv.¢

T.med sup. @®®®00@8000 ig 2

Maj. Coverts + + +++ +++ 4+ +

Remiges @@ @@BOOOO0

Maj. Coverts ++ +++ +++ +4
e@eero000cgdgdn0

Right Side Wing of
Spec. No. 7. juv.é

T. med. inf.

©e820080°000e0 Fig. 3.

Maj. Coverts +++ +++ ++4++4

Remigs @MOOO@ iOO0
Maj. Coverts + ++ +++ +++ +4
T. med. inf © 6G ®OQO8O@ @oa

T. med. sup.

Right Side Wing of
Spec. No. 11. juv.¢

T. med. sup. © ®© @@®®@800 aig

Maj. Coverts + + ++ ++ ++ ++
Remiges @@ ©@@MD OOO 0

Maj. Coverts+ +++++++++
T. med. inf. @® @®@O00000

Right Side Wing of
Spec. No. 12. juv.9

Various phases from the Moult of the Median
Coverts on Metacarpo-Digital Portion of Wing.

Metacarpo digital
portion

distalarea proximal area

TABLE V.

To face p. 886.

x K VIVI WV WM n-r Fig. 7.
T.medsup 00 OO000C00 Bi
Maj. Coverts + + +4 4 44 4 4 4
i Spec. No. 14. juy. ¢
Remiges @®@ @@ OOOO OO Rignt siae wing

Maj. Coverts absent

'T. med. inf.

T. med. sup. @ © ®©60@8000 Fig. 8.

t+ tbe + tt

Remises @@@OO08O OO Pee. No.17. aas

Right Side Wing.

Maj. Coverts

©®0000000@e@
=— meas

Maj. Coverts absent

T. med. inf.

T. med up © ®@@@890000 Fig. 9.

Maj. Coverts + + + + + + + + + +
' Spec. No. 11.j
Remises @@ O®OOOO O@ Fer, sad wen?

Maj. Coverts absent

T,med.inf ©8 DOO008 880
ItimMvvvuivww «ox r,

T. med. sup. @ @ @ e©0CeCOe Fig. 10.

Maj. Coverts + —- + + + + + + + +

Remigss 9@ OOOGO® @@ Spec. No. 24. ad.é

4 Left Side Wing.
Maj. Coverts absent

T. med. inf. ©

Various phases for the Moult of the Median
Coverts onthe Cubital Portion of the Wing.

@ea00060@0

—>

Metacarpo digital

portion
distal area

T.med supe O98 @®000880—O0O 0037308
Maj. Coverts+ ++ ++ +++++
Remiges © @@ @2 OS O©O—O© OD OOOSL GO © Femiges

Maj;\Coverts)—- oe ee et

Fig. 5.

V proximal area.
© T. med. sup.

+++ ++ ++ + + + Maj. Coverts
Spec. No. 15. juv.é
+++ +++ + + + + Maj. Coverts

T. med. inf © © © ®O 00 ®@ ® ®—®@ @9@00O0 O @ @ ®@ @ T. med. inf.

Left side wing

Metacarpo digital
portion

distalarea proximal area
— —<

A Right side wing
Metacarpo digital

___, portion
VV proximal area distal area

T. med. sup. © @ © @O O ~

Maj. Coverts + + + ++ ++ +4 +
Remiges © ®@ O@ OOMO@QO—O OOOO OO SO © Remiges

Maj. Coverts 4-4 tt EE EOE
@e@e © ®—e ©0080 02 O O F, med. inf

Fig. 6.

T, med inf’ 0 O = O:

E, Degen, del, Left side wing

@ @ 0—@ ©6600660 0T med mp.

+++++ + + + + + Maj. Coverts
Spec. No. 10. ad.6
++t+t ttt + + + Maj. Coverts

Bale & Danielson, Lid .

Right side wing

Diagrams explaining Relationship of Growth between the Dorsal and Ventral
Median Coverts for the two Hand Portions of the Left and Right Wing.

MR. E. DEGEN ON ECDYSIS. 387

The moult of these inferior medians, moreover, appears to be more erratic than is
the case for the corresponding dorsal row of coverts. Besides this there exists a strong
tendency to adhere to the conditions of the first endowment, in which the whole series
is provided by a gradual advance of the growth from the elbow- towards the wrist-joint.
The young female, No. 14 (see diagram Table V. fig. 7), is a particularly typical case
of such a repetition of conditions, and so also is No. 4, a younger female still, as regards
its left side only.

It is not, therefore, until the more matured specimens are consulted that the same
plan as the one ascribed to their dorsal companion-coverts will be found to have been
resorted to, namely, the moulting of the feathers within the groups in distinctly
alternate directions. Even this, their ultimate order of perfect synchronism of
movement with their respective remiges and major coverts, is not achieved by any but
positively old birds, and that tendency to retardation, as referred to above, prevails for
a considerably longer period of the bird’s lifetime. The diagrams for the specimens of
Table V. figs. 7-10 further supplement the explanation given above for the relative
position of the ventral to the dorsal median coverts.

This conservative tendency is fully borne out by specimen No. 17 (Table V. fig. 8),
which, although being entitled in other respects to be put down as an old male, has,
nevertheless, only four of these coverts renewed in proportion to the eight cubital
remiges on both wings; these are inner coverts 9 and 10, and the outer coverts | and 2.
No. 20, too, with the same number of remiges renewed already as No. 17 (the previous
specimen), has only two of these coverts in moult.

This tenacity to adhere to the juvenile conditions of growth is carried far within the
erouping arrangement also in No. 11 (Table V. fig. 9), in which it is adhered to in
the first group, comprising coverts 8-10, whose numbers instead of being renewed in
this, their ultimate numerical order, are being still renewed in inverse order—that
is, from 10 to 8, as they would be in a bird of the first season’s plumage. On the
other hand, this same individual shows for coverts 1, 2,3, and 4 (inclusive of the carpal
covert), which form the members of group 2, all the conditions followed by a bird of a
more advanced stage, by beginning the moult from the carpal joint to the 4th, 7. e. from
the wrist towards the middle. ‘The old males, Nos. 24 (see also diagr., Table V. fig. 10)
and 25, approach the conditions of perfect synchronous development with their flight-
feathers; and, further, the old male No. 1 equally bears reliable testimony on its left
side for inferior median covert 8 being the first to be renewed, together with its
corresponding main quill.

In addition to the remarks made above on the subject of bilateral symmetry, it
should be pointed out that not only are cases of asymmetry more numerous when
compared with the corresponding two cubital portions of the wing, but also for their
hand-portions. Thus, in old males three out of a total of eleven are asymmetrical ;

VOL, XVI.

o

part vil. No. 6.—Aay, 1903. ay

588 MR. E. DEGEN ON ECDYSIS.

young males one of two; also the single old female which represents the moult of this
series is asymmetrical for the metacarpo-digital portion ; and of the four young females

three are similarly affected.

Tectrices tertiz serii s. minores.
1. Superiores.

Although this series of coverts is of minor importance to the flight-power of the
wing, the manner in which they moult is of some morphological consequence.

Metacarpo-digital Portion.—On the manus the dorsal coverts of this series fre-
quently precede in moult the other satellites. This they generally do in the same
order as those of the higher series. But, as happens sometimes in the case of
their cubital equivalents, several of them make their appearance simultaneously.
They are unimportant for the covering of this part and of abortive growth.

Cubital Portion.—Here these coverts are confined to a single row also. The typical
manner in which they are renewed imparts to them a special morphological feature,
which is of some value as regards the definition of the different series.

Their moult differs markedly from their neighbouring rows of ‘“ marginal coverts ”
on the patagium and of the true covert-feathers whose description has already been
given.

Their moult consists in a successive supply which begins with the innermost—
contemporaneously almost with that of the feathers constituting the “ parapterum,”
which latter in its turn follows that of the “humeral tract,’-—and ends with the
outermost. The coverts of this series do not take part in the grouping arrangement
which is so characteristic a feature in the major coverts and the medians—not even in
the fully adult.

The tendency for simultaneous development of three and four feathers is very
prominent, and prevails more or less in every perennial moult. Whenever such is the
case, it invariably takes place from within outwards, viz. the 10th to the Ist.

Furthermore, this mode of renewal distinguishes the row from the marginal series,
whose renewal, although following the same outward direction generally, takes place
in patches which begin on the anterior edge of the patagium, whence it spreads
over both the dorsal and the ventral side of the wing in such a way that the several
longitudinal rows are diagonally affected at the same time.

Thus it is through the agency of the moult principally that their morphological
character as a row of covert-feathers can be equally established as being derived from
a different source than either the higher series or the marginals. Where, as for instance
in the more primitive forms of birds, the minors consist of several rows, these are
generally made conspicuous by reversed overlap, a feature which has so greatly
engaged the attention of Mr. Goodchild (27).

MR. E. DEGEN ON ECDYSIS. 389

2. Inferiores.

Metacarpo-digital Portion.—The feathers which constitute this series of minors are
of such abortive growth that they are practically of no value for the covering of this
part, and, as a consequence, no information is available with regard to the order of
their renewal.

Cubital Portion.—The feathers of this row, not so much on account of their
diminutive size (being scarcely 2 the length of the medians), but because of the
method of their renewal, are well worthy of a more special consideration.

It would seem that, with the suppression of the major coverts on the underside of
the wing in the Passeres, the physiological functions of the latter had been transferred
to the next row, viz. the medians, and in the same way that of the medians to the
minors. Both these series have their moult more accentuated and more in keeping
with that of the higher equivalents of the dorsal surface.

The first appearance of the members of this co-series is somewhat earlier than that
of their dorsal congeners in the very young bird. In Nos. 7, 8, and 9, for instance,
all very young individuals and of early dates, this row moults in advance of the dorsal
one. Singularly enough, in the three specimens mentioned, the renewal begins at the
carpal flexion, and proceeds inwards, which is in an opposite direction to the renewal
of the dorsal series. This fact therefore foreshadows the ultimate method of moulting
in groups, and is significant.

Specimens 5, 11, and 12 are examples of the earliest, or caducous, mode, in which
the inferior row is developed strictly in syncbrony with the members of the dorsal row.
No. 12 makes an exception, perhaps, so far that the coverts of the inferior row are
all in a nascent state only, and they are consequently in arrear of those of the dorsal
row, whose components have developed 2 of their ultimate length, and symmetrically
from the two wings.

The transition from the premature to the fully mature condition of moult ts a very
erratic one for the whole series. In the few specimens, however, which show such
evidence of transition, as, for instance, Nos. 13 (both sides), 15 (right side only), and
16 (left side), group-moulting sets in first, sometimes for the proximal, sometimes for
the distal group, and in one case contemporaneously for both these groups; whilst the
middle group, consisting of coverts 7, 6, and 5, does not appear to be affected until
much later.

In any case, asymmetry seems to be a conspicuous feature in the replacement of
this set for the individuals undergoing transition from the juvenile to the mature
conditions of the moult. The coverts of this, as well as those of the dorsal series of
minors which are allied to the remiges of group iII., namely 7-5—the last to change
in every case,—moult in advance of the latter. ‘This is well seen in all the specimens

312

a

390 MR. E. DEGEN ON ECDYSIS.

from Nos. 17-23, neither of these individuals having as yet acquired remiges LV.,
V., and VI,

Approximate Tabular Arrangement showing the Development for the Dorsal and the
Ventral Series of * Median Coverts” during four consecutive Perennial Moults.

Rows. Groups. Sets.

f Simultaneous ........ Ist 2nd—4th Ist Season.
Soppnyerreoiaccens :

Gradual’ (ae ceeeneeere 2nd—4th Ist-2nd 2nd—4th -

f Anachronous ...-.... Ist—2nd Ist-3rd Ist-srd a‘
MovEeMENT ...... )

{ Synchronous ........ 3rd—4th 3rd—4th 3rd—4th 5

| INV AHN Go 05000000 , 1st-2nd 2nd—3rd 1st-3rd Fr
DEVELOPMENT .... 4 _ . ;

PMH Gooogen4a0 2nd—4th 4th 4th 5

VII.—SumMARyY oF THE ORDER IN THE PERENNIAL MoULt of THE WING-FEATHERS.

The Remiges.

Two distinctly different principles in the order of the shedding and eventual replace-
ment of these feathers are conspicuous. ‘The first is that of the regular sequence
of their renewal on the hand-portion from within outwards, though accelerated in
certain places or retarded in others, in order to maintain the requisite balance for
flight, by a system of approximate symmetry for the whole wing during this critical
change. ‘This is the principle which forms the rule for probably the entire Order of
the Passeres.

But it is by no means the expression of the real morphological process of
development which takes place, as we shall have an opportunity to prove further on
when studying the behaviour of the covert-feathers during the moult. The true
morphological principle is probably concealed beneath this purely secondary feature.
In less highly organized birds, such as the Picariz, an earlier and more primitive mode,
namely, that of starting the moult on the manus from two separate points almost
simultaneously, has been observed by Wittmer Stone (44), in the case of the King-
fisher, who (on p. 112, /. ¢.), after remarking on the principle of his “‘ Order of Molt,”
writes thus :—

«Following these [the two innermost primaries] the primaries are shed at short
intervals, one at a time, finishing with the outermost. Haceptions I have noticed to
this order in the Belted Kingfisher, Ceryle alcyon, and the Snow-Bunting, Plectro-

9

phenax nivalis”. And further on (p. 113, 0. ¢.):—“The Kingfisher is strikingly

» These italics are mine.
* Wittmer Stone, on p. 113, also quotes the case of a male Piranga.

MR. E. DEGEN ON ECDYSIS. 391

different from any other bird examined in that the first wing-feather molted is the
fourth primary, followed successively by the third, second, and jirst }” *.

This same rule the author seems to have verified on the hand of three specimens in
the same stage and coming from the same locality. But he continues :—“ How the molt
proceeds" after the first primary is shed, I am unable to say, though the fifth} [our V1. |
is probably the next to be renewed, followed by the others in regular order inward.”

It was my good fortune, when in Australia, to procure, as the first bird which I
collected for this purpose, a fine specimen of a Brown Kingfisher or Laughing Jackass
(Dacelo gigas) about the middle of the annual moult, so I am glad to be able to
supplement the information desired on the point. According to my observations, the
moult proceeds on the hand-portion—after having done so from the 7th outward—
by immediately starting with the innermost or primary I. In the specimen observed
by me this feather was nearly fully developed and further showed the second or next
innermost in full process of moult, and the third cast off, preparatory for the renewal
of this remex. Primary L., therefore, is the centre from which this section of the manus
begins to moult next. This section comprises metacarpo-digitals J., I1., IIL, 1V., V.,
and VI. Although this section moults in arrear somewhat of the outer one, comprising
VIL, VIII., IX., X. (and XI.), yet, apart from its inner position, from a SE eons
point of view, it has to be considered as the first of the two.

I have elsewhere alluded to this arrangement as being overshadowed by a later
principle in more specialized birds; similar signs as those referred to here for the
remiges exist in some of the series of the coverts of the metacarpo-digital portion,
and this is the same primitive principle as carried out more generally on the cubitus.

Gerbe (23), on p. 290, 7. ¢. (see also anted), was the first to point out a deviation
for the forearm, from the linear progress of the moult of flight-feathers on the hand-
portion ; he, however, confined himself to this statement merely :—‘‘ Elle se manifest a
la fois sur les deux points extrémes du cubitus et prend deux directions qui tendent
Pune vers lautre.” Beyond this he did not pursue their order of moult.

This I shall deal with in the course of my remarks on “Groups.” As the initial
diagrams A, B, and C show (Plate XX XVI.), the first one of these groups in which
the moult sets in embraces cubital remiges VIII., IX., and X., which are renewed
in the order of these numbers—that is, in a proximad direction.

Meanwhile the moult has set in also on the other extremity, beginning with cubital
remex I.,and by assuming the same inward direction as the group previously mentioned.
This it does as far as the fourth quill, which forms the last one belonging to this group.

* These italics are mine.
* Wittmer Stone counts from the tip inwards, so that his fourth is probably the seventh (possibly the eighth
in an eleyen-primaried bird), after our reckoning ; his third our eighth; his second our ninth; and his first is

consequently identical with our tenth, at any rate last and outermost.

392 MR. E. DEGEN ON ECDYSIS.

The latter, which I refer to throughout as Group IT.(comprising remiges I., IT., I11., [V.),
consequently forms the other “point extréme” of which Gerbe speaks. We have
disposed, then, of two groups, whose remiges severally tend in the same inward direction
for their moult.

This leaves us with a balance of three flight-feathers situated between the proximad
limit of Group II., viz. remex IV., and the distad limit of Group I., viz. remex VIII.
Y'he moult, however, of the remiges of this centrally situated, or Group III., proceeds
in an opposite direction (that is, in inverse order of their numbers), namely by beginning
with remex VII., then VI. and by closing it with V. In the chart (Table IT.) prepared
for the chronological movement of the remiges (further see diagrs., Plate XXXVI.
&c.), their alternate directions of moult are indicated by darts, pointing in the respective
direction of their renewal.

In this way the order of the moult of each flight-feather itself becomes a definite
unit of the group to which it belongs.

Similarly, as has been explained, each group itself becomes a definite unit in the
cubitus as a whole.

Consequent upon the synchronous appearance of two or more group-integers, the
numerical order in the replacement of the flight-feathers within the cubital portion as
a whole breaks up.

, The Tectrices.

The renewal of the wing-coverts presents some notable deviations from that of the
flight-feathers.

Whereas the latter adopt the ultimate plan of renewal in sections immediately in
their first perennial moult, the wing-coverts do not follow this same principle so
soon, except by means of a series of transitory stages. These latter form a system of
complexity in which two entirely different morphological features seem to mingle with
each other: the one an early horizontal or diagonally longitudinal, and the other,
later one, consisting of a transversely diagonal one for renewal.

As might have been noticed, a certain amount of difficulty occurred in tracing out
the two systems of development. However, in following up step by step the order of
renewal of the coverts—providing an extensive series of individuals be consulted on
this point—all the conditions in the physiological process of their perennial moult
may be found for discriminating between the various phases which produce this state
of complexity.

But in order to better comprehend the degrees of complexity attending this interesting
morphological question, it has become necessary to refer fo some of the statements
made on the subject of those writers particularly whose works have appeared in more
recent years.

The observations made by Gerbe (23) on the simultaneous shedding of the principal
coverts for the hand-portion of the wing have been described fairly correctly by

Mk. E. DEGEN ON ECDYSIS. 393

him on p. 290, d.¢., thus:—‘*. . . leurs grandes couvertures qui sont pour le vol un
élément important /es accompagnent towours dans leur chute” !. ‘These researches led
him also to the statement, recorded for the first time, of the two opposing directions
which these coverts on the cubitus pursue for their renewal, as the flight-feathers ;
and further that here (on the cubital part) they are developed in advance of their
respective remiges (see p. 290, J. ¢.).

To what extent this latter and more general statement is correct may be verified
from the facts as they appeared in connection with the part dealing with these feathers.
The degree of advance, as could be seen, depends upon the age of the individual.
The moult of the coverts also follows the direction of the flight-feathers. This direction
is not one of opposition from the extreme points of the forearm, but one which
converges for the distad and the medial groups, and one which diverges for the latter
and the innermost group. Gerbe did not investigate the appearance of the minor
series of coverts.

Chalmers Mitchell’s (12) interpretation of the longitudinal appearance of the flight-
feathers and their principal coverts is that they are the co-serial members of a
diagonally transverse arrangement with the other coverts, like that existing for the
scaling in Reptiles, and as further diagrammatized by him in his text-figure on p. 232,
l.c. This on p. 230 he explains thus :—

“©... . the quills and major coverts appear first as horizontal rows. It is only when
these become obvious, and when one or two other longitudinal rows appear from
before backwards, that the diagonal rows begin to be marked, &c.”

And continuing further :—

«. ,. .. 1 am not, however, prepared to attach great importance to this early onto-
genetic appearance of the longitudinal rows as such.”

As the result of this investigation also shows, there is in reality a marked transverse
or vertical element entering into the composition. Though but faintly indicated in
the chick’s first perennial wing-feathering, it gradually increases with every subsequent
moult by which the bird attains to perfect conditions of maturity and age. ‘This
transverse arrangement is a survival, therefore, of the phylogenetic affinities which link
the present Class Aves to their Saurian ancestry.

The horizontal or longitudinal sequence of growth of the rows, applied to every
series of the coverts (as well as the main quills) in their entirety, is the result of a
secondary provision, and of a purely ontogenetic origin, which is assamed by the
embryo and the young bird for its first set of wing-feathers.

Afterwards this same sequence of renewal becomes restricted to those sections of the
rows which form part of the several groups on the forearm. Within these groups
the horizontal renewal is retained throughout every moult. Hach of these three
sections performs this longitudinal process independently of the other two.

1 The italics are mine.

394 MR. E. DEGEN ON ECDYSIS,

The great importance which attaches to the covert-feathers in helping to clear up
outstanding questions connected with the evolution of the organ of flight was fully
recognized by Mr. Pycraft (39), who has approached the subject of the origin of
Diastataay from the point of view of Embryology. In the course of his description
of the * Embryo Wing”’ (see p. 239, /. c.) he says, for instance:—‘t The movement of
the remiges is in all cases accompanied by a corresponding movement on the part
of the coverts associated therewith, from the post- to the pre-axial border.”

And continuing, he says:—‘'The result, when the wing is viewed as a whole,
seems to show that a process of ‘faulting’ has taken place, &c., &c.” This process
of faulting or shifting he, moreover, supports by an ably devised diagram (see
p. 239, 7. ¢.).

It is really the first indication of a transverse rearrangement of the rows at this early
stage of development. ‘That it is a totally distinct feature from the longitudinal
principle of feather-supply is equally endorsed by this author, who initiates, on p. 238,
the paragraph treating of the subject by the following words :—‘“ In all wings the
feather rudiments appear first along the post-axial border of the wing; those repre-
senting the remiges and their major coverts appear simultaneously, and sometimes
together with very faint traces of one or more of the pre-axial rows representing the
median and minor coverts.” And further:—‘‘The change takes place, however,
generally at the close of this phase of development.”

Now it is this “faulting” precisely on which Goodchild in his researches has laid so
much stress, and which has supplied this author with such a solid basis for his obser-
vations on the coverts of the cubitus. Further evidence of a transverse character he
has clearly also shown to exist in the alternate imbrication of the members of certain
series of coverts, which is so conspicuous a feature in a great number of families
of birds. Similar indications of this principle may be found to exist also in the
shape of the permanently shortened coverts which mark the various sections of this
portion of the wing for some families of birds (Degen (16), p. xxii). Their places
almost exactly correspond with what we have learnt through the conditions under
which they moult.

The appearance of a first set of wing-feather-plumage is an endowment of secondary
origin. It is the common bondage for all Carinate birds. In the Chenomorphe, for
example, this early ontogenetic mode of feathering is repeated more or less in every
moult (anted, p. 366) for both portions of the wing.

In more highly organized forms, however, this latter mode is confined merely to the
very young individual on the cubitus, in which, with every succeeding annual moult,
the transverse character of primitive origin comes into prominence.

The latter reveals itself also by the moult of both the flight-feathers and the coverts
on the metacarpo-digital portion in some families of the Picariw (Kingfishers) ;
whereas in the Passeres, whilst being merely concealed by a chronological difference

MR, E. DEGEN ON ECDYSIS. 395

for the remiges and the major coverts of this portion, it is wholly retained by the
median, and in part by the minor series of coverts still, as evidenced through their
moult.

VIII.—Tur Contour Fearugr-Tracts, on Preryin.
Preliminary Remarks.

No really so precise a description of the order which the moult pursues in these
tracts is possible as that which enabled us to follow it for the “ alar tracts.”

One reason for this is that synchronous renewal is not circumscribed so definitely on
the body as it is on the wing. But on this head I cannot do better than quote
Dwight (17), whose statement, p. 84, /.c., under the heading of “ Advance of Moult in
the Feather-Tracts,” is as follows :—

“The only way to get any idea of how a moult proceeds is to appreciate the fact
that it begins almost simultaneously at a number of points in the different tracts, and
advances independently from each of them. ‘This is why a bird seems to be moulting
at irregular spots all over. ‘There is, as might be expected, a good deal of individual
irregularity in the growth of new feathers, but when each tract is studied separately,
each will be found to have a definite plan of development, which in its turn fits into
the general scheme of the process we call the moult.’ And, again, in connection
with this subject on Gulls and Terns (18), as regards “Sequence of Moults and
Plumage of the Laride,” he says (p. 50) :—

“The moults occur at definite periods, and the feather-growth spreads from definite
points in the feather-tracts, so that nothing is a matter of chance unless it be the
arrested development that befalls all organisms, and occasions in birds the retention of
old feathers among those that are replaced by new ones at time of partial moult.”

The above statements so exactly describe the conditions that exist in the species
under consideration that I can add very little else to them as the result of my own
investigation. In consequence, this account can be restricted to the narrowest limits
by merely pointing out a few specific deviations from the broad principle.

A second reason for not being able to make a comparative survey of the moult in
the various body-tracts consists in the technical difficulty presenting itself of dealing
with them simultaneously, the same as they are in moult. ‘This difficulty is further
enhanced by the fact that this not only applies to the tracts themselves, but, as
pointed out by Dwight (see anted), to the different parts of a tract by the new growth
which spreads in both a diagonal, transverse, and longitudinal mannner.

Having, moreover, early recognized the desirability to adequately express in some
manner of form the complex order of moult, besides the systematic description of the
different tracts, [ have prepared a chart (Table VI., p. 598) as the only alternative
for intelligibly conveying the relative order of their moult.

* The italics are mine.

VOL. XVI.—PART VIII. No. 7.—May, 1903. 3K

596 MR. E. DEGEN ON ECDYSIS.

In this chart are entered all the tracts and the various longitudinal rows of feathers
of which they consist. ‘The rows against which an asterisk has been placed are those
which form centres from which the moult proceeds. The pointed ends of the blackened
bars denote approximately the beginning of moult of that particular row of feathers.
‘The time of the completion of the moult for the same is indicated at the point where
the shading reaches its maximum by filling up the space between the parallel lines
which divide it from the neighbouring bar.

Beginning and completion of the moult of each row is measured by the common
standard, namely, that of the development of the Metacarpo-digital Remiges, whose
numbers in this order from right to left are placed at the head of the Table, as are also
those of the Cubitals and the Penne pollicis for chronological comparison. A similar
arrangement has been provided in this table for the rectrices and their coverts at the
bottom.

The Spinal or Dorsal Tract (Pteryla spinalis).

This is of a well-defined Passerine form, and partakes of the type under which
« Nitzsch” (37, pp. 79 & 80) subordinates Cuvier’s Group of the Dentirostres as follows :—

CCAG Vath orecitices.
“a, Saddle without a space.

“1. Barita—.... saddle short, broadly rhombic, acute angled. BB. strepera,
B. destructor, B. varia.”

But it also partakes in part of the description which follows for the characters
applying to his second division of this group, between which it seems to fit in, namely :
*©2. Thamnophilus, seu Vanga, and Lanius, species undulatus and procerus,” in which
he refers to ‘‘ twenty remiges which are all very broad and obtuse, graduated as far as
the fifth [our VI.], which is of the same length as the sixth [ V.] and seventh [IV.].”....
And further: ‘“.... the saddle is heart-shaped reversed, emitting a single row of
feathers from its middle as the commencement of the rump-band.”

From this definition of the rump-band Gymnorhina tibicen deviates by emitting not
only this single row, but two additional ones as well, whose feathers alternate by means
of quinqunx from 3 to 2 for about 7 or 8 of these sets, from whence a short distance
backward to the oil-gland the tract broadens further out into two more additional rows,
making 9 in all.

The saddle portion itself in its widest diameter, which is placed two-thirds back-
ward, consists of 12 rows, tapering out to 6 rows on its anterior or interscapulary
portion, which further in front widens out into from 2 to 3 additional lateral rows,
from which latter region it broadens out into the head tract.

I have found the moult to proceed from three distinct main centres on the principal

MR. E. DEGEN ON ECDYSIS. 397

part of the spinal tract, and it affords me great satisfaction to have independently —
arrived at the same result as that of Mr. Dwight, whose paper I did not see until towards
the close of my work.

Of these, one proceeds from the lumbar, one from the thoracic, and one from the
interscapulary region (this latter beginning to moult later: see Chart, Table VI.). In
addition to these main centres, there is to be noted another for the portion to which
T refer as “ the Lower Neck Region” in the Chart. I have also pointed out the lateral
rows as such, from which moult proceeds later, as a secondary feature.

[ am also able to state that I had a similar notion about the agency of the blood-
supply possibly influencing the early moulting conditions of these centres, as referred
to by Dwight (/. c. p. 84), to which the specimen No. 12 testifies, and from which
the present description of this tract is made, by having used a carmine injection for the
purpose. In this I failed to procure the desired evidence, on account of some
unsuspected internal injuries by shot.

From these main centres the moult spreads both forward and backward simul-
taneously, but slightly more in proportion in the latter direction. It shows signs of
energetic progress nearly always in advance of any remiges, as shown in my earliest
acquired specimens. It is also protracted during and often beyond the latest phases of
development of flight-feathers, as specimens in which the moult of the latter is
completed show. The middle row is in full vigour of new growth, and approaches
completion much sooner than the time of appearance of primaries III.-IV., as shown
on the Chart; the crown of the head, and notably the auricular regions (lores, &c.),
being the latest of the lateral rows to change, except the sides of the nape.

The Humeral or Scapulary Tracts (Pteryle humerales).

Pterylographically, this tract, which is a double one, has been defined by Nitzsch
(37, p. 25) as being entirely divided by space (the lateral Apteria spinale) from
the spinal tract previously considered. Although being more directly connected with
the “‘ inferior tract” by means of a band of closely-set rows of feathers, it is linked,
nevertheless, in this particular species to the “spinal tract” by a contiguous set
of softly-textured feathers consisting of about three rows. ‘These are placed across the
clavicular region in front of the head of the humerus, thus bisecting the long spinal
apteria, a similar arrangement as that ascribed to some birds by Nitzsch (p. 25, /.¢.),
e.g. Séteganopodes, Buceros, and Colius, which, as he remarks, “‘ may nevertheless be
recognized as distinct tracts by the stronger formation of their feathers.”

The humeral tract may be subdivided into two distinct portions, each with a well-
marked centre from which the moult spreads independently, a humeral and a clavicular,
or more marginal portion, the latter merging into the alar marginal tract. Both these
consist of several rows after their bifurcation. Of these, those medially situated are

3K 2

398 MR. E. DEGEN ON ECDYSIS.

affected earliest, and simultaneously with the corresponding rows of the spinal tract ;
the internally and externally situated ones which compose these branches begin to moult
somewhat later, about the same time as the renewal of primary remex III. ; this is also
the case with the lateral rows of the thoracic portion of the spinal tract. The moult
for the feathers of this tract on this part of the body sets in most vigorously, and is
achieved at a comparatively earlier period than that of the dorsal main stem.

Closely allied to the distal rows of its humeral branch are the feathers which
compose the “ Parapterum.” Only a narrow space separates the two. ‘The feathers
of the latter take up the moult from the humeral branch, and in younger birds are
replaced by synchronous appearance, whereas in older individuals they are renewed in
more regular sequence from within outwards.

The more marginal branch spoken of, and entered also in Chart (Table VI.) as
* clavicular,” follows the same principle for the moult of its feathers as that which
applied to the former branch. Its distally situated rows on the underside of the wing
establish a connection with the “ Hypopteron,” from which it is but slightly separated
also. The feathers of the Hypopteron, which are a somewhat rudimentary set (being of
a filo-plumaceous structure), begin moult—which is always a simultaneous one for
them—later than those of the Parapterum, their appearance corresponding with the
renewal of primary V.

The Inferior or Ventral Tracts (Pteryle gastrei).

Commencing with the chin, and covering the throat in one homogeneous mass,
together with the head and sides of the neck, with which portions it coalesces, this
tract divides itself into two stems in the gular region, which descend in a laterally-
curved line towards the anal region, without, however, reaching the orifice. These
two stems enclose the apterium mesogastreum of Nitzsch (p. 34, /.¢.). Excepting the
portion of the throat mentioned above, its rami may be further subdivided into
“pectoral” and “inguinal” portions respectively. The former are of considerable
width, and consist of about from eight to ten longitudinal rows of feathers in their
broadest parts. These send off the lateral extensions, backward and outward, referred
to by Nitzsch (cf. p. 27, 1. ¢.) as pteryle laterales, more prominently perhaps in the
species under examination than in those Passerine forms referred to by the latter author
(cf. pp. 28 & 80, U. ¢.). These small ramifications set off distinctly enough imme-
diately in front of the portion which forms the greatest expanse in the double tract
just below and posteriorly to the arm-pit.

Ata place slightly in advance of the junction of the latter with the main pectoral
portion is the principal centre from which the moult proceeds longitudinally back-
wards, and to both sides of the tract, by renewing every alternate feather, sometimes
overlapping two feathers in either direction. The inner rows of this portion moult
vith great rapidity during the earliest stages of the complete feather-change ; whilst

Trans. Zoot. Soc., Vol. XVI.]

In the 3 divisions above the horizontal line, which is extended to the left, are entered the flight-feathers of
the Alar tract in the order of their moult from left to right.

The metacarpo-digital remiges or primaries for which the Roman figures I.-X. (XI.) have been substituted
are placed in the éop portion of the lower division and serve as the chronological scale by means of which the
moult of all the other tracts with their component rows may be compared.

‘The lettering in the portion below this and immediately over the line corresponds with the lettering for the
metacarpo-digitals in Tables I. & IT. and Plates XXXVIXXXVIII.

The Roman figures in the lower portion of the middle division show the synchronous replacement of
the cubital remiges or secondaries with any of the primaries in moult. They are lettered with dashes
thus: ‘, ", '’, in conformity with that of Tables I. & II. and in Plates XXXVI.-XXXVIII.

Above these and in the uppermost division in ordinary cyphers are placed, according to their order of
replacement, the Penn pollices, synchronous in position of their moult with those of the respective remiges.

Hach shaded bar represents the moult of the respective rew or rows of feathers, denominated as such to the
left of it.

lis pointed end indicates the commencement of the moult of the row of feathers which it represents.

The tapered portion of the bars from the tip to the angles which its sides form with the parallel divisions
of horizontal lines, shows the comparative amount of moult for that row.

At the place where the shading fills up the parallel divisions, the moult of this row of feathers is completed.

By means of the vertical division lines their respective stages of moult may be read off on the scale provided
for the moult of those remiges with which these stages coincide.

A x against a unit of rows or a particular row signifies that this is a particular centre from which moult
proceeds.

The rows which constitute a tract are bracketed together and are headed by the pterylographic name of
their respective position.

The latter are bracketed together again according to their anatomical position on the bird, and denominated
as such at their head.

The division at the foot of the Table is devoted to the synchronism in moult for the tail-feathers by means
of bars for the coverts, both dorsal and ventral, and by their respective numerals for main quills or rectrices.

Pennee Pollicis —~

Cubita/s —

Metacarpo -digitals —

lateral rows

To face p. 898.

TABLE VI.

2

he’

QO | Of 0. %. Up.) M /1/
V VI | Vi | VII

remicle
ohsent

ie
INGE

all

nH
li
|

Thoracic
ortson
ie median ,,
median
Trunk lumbar x
‘i
LEE Jatera/
externa/ ,,
Interscapulary|
portion x centre/
Spinal internal ,,
Tract
median
Lower Neck X
Jateral
median
Nape
Jateral
Crown X
Head
Lores

elgg
i
il
ih

centra/
Humeral xX

portion

Parapterum
Scapulary Tract
Hypopleron

distal rows

Clavicular, COA op
portion
proximal .,

:

median rows
Throat x
ortion
aaa lateral
medisn
Ventral Tract fetes x
retro.
(heat /atera/
oxime!
/nguineal 9% Gee ue
portion 2
osstal

Femoral or Lumbar Tract
inner
portion

Tibial Tract

outer

portion

Upper Coverts
Lower Coverts

Main Quills

FRectrices

BE. Degen, del,

proximal rows

Hie

nen
ne
Po

i
a

i
i

Baa

f

Ec
ie
oe

RaRE

To
THE

oil

aii
|

Pd

a I
= i Ea
ee ae eae
SS SSS Se = |
Se
j=
| eee :
ae
eee na Same a oC hl
ea ae a LU
TSE z = b23 | vi Ls te ZB 2 Moult
i E d le 2 3 3 4 A 5 $ 6 6 complete
Bale & Danielsson, Ltd.,

Chart showing the correlation of growth amongst the feather
tracts during the period of the moult.

MR. E. DEGEN ON ECDYSIS. 399

the lateral rows, both internal and external ones—to which latter the pteryle laterales
belong,—do not take up the change until considerably later, viz. the stage of renewal
of primary remex VIII.

The centre of moult from the other, namely, tine of the ‘‘ inguinal” or gastric
portion

which is a continuation of the pectoral one, consisting of three or four rows
of feathers only,—begins also synchronously with that of remex I., or directly after.
The progress of renewal of the feathers of this portion is much slower, though slightly
faster in the case of the innermost rows than the lateral ones. This condition points
to the fact that the inner rows are really equivalent to the median ones of an
undivided tract.

The third centre of feather-renewal for this tract is at the point of bifurcation for
the two pectoral rami on the lower throat. Contrary to the mode of moulting, in an
antero-posterior direction, of these latter, the moult of this portion proceeds in a forward
direction only, until it finally reaches the mentum. It is not till much later on in the
season of general moult that it sets in here ; but when it does, it happens in a vigorous
manner, which is about the time of remiges VI. and VII. for the central rows. These
are followed immediately by the outer rows, which complete their moult at the time
of renewal of cubital remex V., the last of the flight-feathers to moult.

The renewal of the feathers of this tract in the order in which it has been described
here is that of the older individuals. In younger birds this order is not so clearly
defined.

The Femoral or Lumbar Tracts (Pteryle femorales sew lumbales).

These are composed of two rows, consisting of nine or ten soft and elongated contour-
feathers each. ‘They are renewed in alternate rotation—that is, by beginning in the
superior row with the feather which is situated nearest the apterium spinale, to be
followed by that of the inferior row next to it, and from whence the feathers are
renewed in tolerably regular sequence in backward direction. ‘Though the feathers of
this double tract are only few, their renewal, which begins with the earliest phases
of the flight-feathers, is not completed till about that of remex VIII.

The Crural or Tibial Tracts (Pteryle crurales).

Both portions of these tracts, which clothe the tibia—an inner and an outer one—and
which are separated in their upper or femoral portion by an apterium, merging with
each other below the knee, moult simultaneously. The moult begins early and
synchronously with the centre of moult of the other tracts, from above below, and
finishes on the tarsal joints. The time of completion corresponds with the last stages
of flight-feather renewal. This is somewhat remarkable for a tract which consists of so
few feathers, seeing that their renewal begins at a comparatively early period of the
perennial moult and finishes so very late.

400 MR. E. DEGEN ON ECDYSIS.

The Rectrices and their Coverts.

The tail-feathers are replaced in a perfectly regular order from within outwards, as
are also their coverts, both dorsal and ventral. ‘These coverts consist of two rows
each, equivalent to the major and the median coverts of the remiges.

The first or innermost pair of rectrices—of which it is sometimes the left, or as in
some individuals the right side, which moults first—is renewed at the time of renewal
of primary remiges III., 1V., and V., or the triplet marked ¢, d, e (see also diagram,
Plate XXXVI., and Tables I. & VI.), as has been pointed out.

About the time of renewal of the 5th primary, the second innermost pair of rectrices
takes up the moult, generally before the first is completed, and, with the next remex
in moult (viz. primary VI.), the third pair follows suit, and so on; the last and
outermost sixth pair coincides generally with the two outermost metacarpo-digital
remiges IX. and X.

lrequently there are as many as three pairs of tail-feathers to be seen in various
stages of graduated length of renewal, but, as a rule, there are not more than two.
The former condition occurs in younger, whilst the latter is the case for older indi-
viduals. ‘Their dorsal coverts take up the moult somewhat later than their ventral
ones, which latter are amongst the first feathers to renew of the whole plumage, as
may be seen, by their relative order to the rectrices, at the bottom of the Chart
(Table VI.).

1X.—COoNcLUSIONS.

Having, in the preceding pages, described the chronological behaviour of the
feathers during the moult of the individual, and further shown, with the help of
diagrams and tables, the relationship of their development to one another, by paying
special attention to the principal feathers, I can now proceed with the explanation of
my views with regard to the manner in which they reflect the phylogenetic conditions
of the archeornithic type from which the wing of the modern bird has been evolved.
For this purpose it becomes inevitable to refer again to the details of the theory
propounded in the pages of my former work (16) and notably so to plate 1. fig. 3,
l.¢., for the views there brought forward.

The present investigation gives me no cause for materially altering the funda-
mental plan laid down in the former paper, other than two slight modifications. ‘The
frst and principal one, referred to already under the part headed ‘‘ Ala spuria,” is the
result of the additional discovery of the inverse order in the shedding and eventual
replacement of the penne alares of this portion, as affording us a likely key to its further
solution. The other point is one of a merely subordinate character, and I propose to
allude to it later on.

Immediately on entering upon the question, our attention once more gets directed

MR. E. DEGEN ON ECDYSIS. 401

towards that point which forms the focus in the whole problem, viz. the diastema, for
the position of the 5th cubital remex. ‘The space between the first primary remex on
the metacarpus and the sixth secondary one is occupied by cubital remiges I.—V.
(exclusive of a carpal vestigial one), with their respective main coverts, which form the
most distal group on the forearm, and here spoken of as Group II., on account of
the moulting of these feathers second in order, and therefore in keeping with this
particular feature.

All the members of this group moult in inverse order, viz. from the wrist-joint
inwards, ‘To these, in my former diagram (pl. i. fig. 3, dc.) of the reconstructed wing,
was allotted a metacarpal position; and, in allusion to their possibly former digital
derivation, they were referred to as “‘ proto-metacarpo-digitals.”

The significance of a similar fact of the “penne pollicis” moulting in an inverse
direction, too, assumes now additional importance through this peculiarity. As
mentioned before (p. 371; see “Ala spuria”), that it probably would matter little
whether these feathers were regarded from a purely remigial or a tectricial point of
view ; this again finds corroboration in this place, since main coverts follow the same
routine order of moult as do remiges. But what really transpires is (especially when
taken in conjunction with the sectional moulting of the flight-feathers on the manus,
as in the Kingfishers and others, and further shown for the dorsal median coverts in
this species) that we have clear testimony in this of the presence of a distinct digital,
and an equally distinct metacarpal, element. ‘To the remiges of the former derivation
therefore alone belongs the term proto-, whilst to the latter belongs that of hypo-
metacarpo-digitals.

If then, as the principle of analogy would justify us in adopting, the same rule by
which the remiges of the former Group II. (and now become our Hypo-metacarpo-
digitals, or further abbreviated “ Metacarpals”) were applied to our permanent meta-
carpo-digitals I—X. (XI.) (or frequently more as in the Ostrich and probably in the
archeornithic wing), the only possible inference would be that these latter are those
of purely digital origin.

As such then, and the fact that both sections of which the series is made up, viz.
from I.-VI., and the other from VII.—X. (XI.) and moulting both in an outward
direction, it is these which now become our true ‘‘ Proto-metacarpo-digitals ” of the
hypothetical wing.

In the “modern wing” those of the outer section alone, namely, primary remiges
(VII. ?) VI-X. (or XI.), deserve henceforth the appellation of “ Permanent Digitals ”
(see former diagram). On the other hand, the primaries of the inner section,
viz. I-VI. (having, in association with synostosis of the metacarpal bones belonging
to digits II. and IIL., been borrowed from their previous phalangeal position on
digit If]. by the now combined metacarpal bones with which they have become

4()2 MR. E. DEGEN ON ECDYSIS.

permanently associated) deserve to be called “ permanent ” only in so far as they are
derived from the same source as the former.

All that remains to be further explained now, after having shown their purely digital
value, are those digital phalanges on which they were originally situated. ‘These could
have been none other than those belonging to digit III., as we shall see.

The crowding together on the wrist of the flight-feathers in their backward-
shifting process towards the elbow caused the forearm to receive first the quills
originally belonging to digit IV. Next to these followed the “ metacarpals” belonging
to digit II. This must have occurred contemporaneously with the process of
ankylosis of the two metacarpal bones, so that these “ digital” remiges in question and
belonging to digit III. found the channel obstructed by their former neighbours, the
‘‘ metacarpals ” mentioned above, which had preceded them in this course of shifting
into their new position on the forearm and in the latter of which they became fixed.
Hence, in the same manner, they became fixed themselves, in turn, on the combined
metacarpal bones.

Another peculiarity which has often arrested my attention also seems to point
strongly to such a rearrangement. It is that of primary digital remex VIL., or,
anatomically speaking, the ‘addigital,” which, instead of having its base inserted,
like those of VIII., [X., X., or XI., on the phalanges which bear them, crosses the
retained terminal phalanx of digit III. entirely, to insert itself above it, together with
the shafts of all those from this one inwards, on the metacarpal bone of digit II. This
arrangement is also distinctly shown in Wray’s (46) text-figure on p. 351 (fig. 2a, Ll. ¢.)
for the faithful drawing of the wing of an adult Ostrich, in which bird, owing to the
greater relative length of this complex terminal phalanx, the shafts of no fewer than
three primaries likewise cross it.

A reference also to my former diagram (table i. fig. 3, 7.c.) shows that in this I
suggested, by means of dotted outlines, a suppositional remex to have been present, as
well as that of the “carpal remex and its covert”; it is marked there I’, and x on
phalanx I. of digit III. When this digit was probably slightly inferior in length to
digit 11., but otherwise composed of the same number of phalanges (see also Wray,
(45), p. 284, “Note on the Vestigial Structure in an Adult Ostrich,” figs. 1-4
representing the digital phalanges of digit III.), it was doubtlessly. capable of giving
accommodation to a similar number of remiges like that composing the inner section
of the primaries, as in the present forms of birds. In fact, Wray shows this number
to be equal for the Ostrich, namely 8 “ metacarpals” and 8 “ digitals.”

The next point of difference to account for concerns those flight-feathers on the
cubitus which compose Group III., the last to moult, and comprising secondaries VII.,
VI., and V. In my former drawing the metacarpal bone of digit IV. is represented as
carrying one remex only, namely cubital VIII.

Having seen that IX. and X. also moult in an inward direction, the inference from

MR. E. DEGEN ON ECDYSIS. 403

this would be that this bone was probably the carrier of more than that remex VIII.
by further including LX. and X. also.

Inferentially, from their outward order of moult, both VII. and VI. being of digital
origin, their position on the first phalanx of digit 1V. would require no other altera-
tion to my former diagram, except perhaps the cubital remex V.—which, according to |
its moult, seems to belong to the set of flight-feathers composing Group ITI. (further
shown in the scheme on p. 404)—takes up the outermost digital position of digit IV.
instead of the most inward metacarpal one to which I then assigned it.

For exactly the same reasons “ carpal remex and covert” become “last metacarpals ”
of digit ITI., instead of being, as interpreted previously, “first digitals” of the same
finger. It is merely a shifting backward by one place in toto, with the further conse-
quence that ‘cubital remex V.” of the specialized Passerine forms requires to be also
theoretically included with the remiges (0 carpal remex) I.-IV., our present Group II.
and the most distal on the forearm, by means of this disposition.

Indeed, the greatly vacillating position in the order of its renewal which this flight-
feather takes up makes it difficult to determine whether it moults last of Group II.
or first of Group III. It seems from four specimens (Nos. 24-27 of diagrams,
Plate XX XVIII., left and right wings) that it is connected directly by moult with the
remiges of the distal group in Nos. 25 and 26; whilst in No. 24 it holds a position
strictly intermediate, the new-growth remiges IV. and VI. in the two wings of this
specimen having been fully accomplished. Its determination as to new or old growth
in specimen 27 being somewhat doubtful (see Table I. parts a & 4, and also diagrams K,
L, M of Plate XX XVIII.), the latter gives no positive information on this point.

This slight preponderance in favour of its closer association with the distal group is
fully counterbalanced by the opposite condition of moult of this remex in specimens 28
and 29, which were both received on a later date, namely March 20, and preserved in
a dried condition on account of their almost completely finished moult. But the
following notes on these, taken down when fresh, will confirm the above :—

“No. 28, ad. 29, March 20.

“Remarkable specimen on account of its white back (albinism or hybrid between
G. tibicen and G. leuconota ?).

“Moult complete with traces of same on wings (both sides) for cubitals V. and VI.
Incomplete on dorsal tract.”

And for :—

‘No. 29, juv. 2, March 20.

“The 6th cubital of the right-side wing a little shorter than corresponding feather of
left. The 5th cubital apparently the old remex not yet shed.”

By preferring the incorporation of cubital remex V. of the Passerine type of bird
with the distad group, we necessarily encroach upon the number of remiges of the
middle group, viz. V., VL, & VIL., which in this case would reduce this group to only

9

VOL. XVI.—PART vill. No. 8.—May, 1903. 3L

104. MR. BE. DEGEN ON ECDYSIS.

two quills, namely VI. & VII. Naturally, then, this would restore to the distal
group the number of remiges allotted to them in my former diagram. And, in
continuing this process of borrowing one remex from group to group backwards
consistently, it certainly would have the advantage of bringing us in positive accord
with the results arrived at in the compilation of my former diagram, namely by ending
with secondary remex VIII.; thus leaving us with remiges I1X.-X. to be disposed of
as “ remiges cubitalis veri.”

But against the inclusion of cubital VIII. in the middle group is seen the perfect
constancy with which the latter remex begins the moult first in all the specimens, to be
followed in turn and with equal constancy by secondary remex IX. It is not till
much later in the moulting-season that in Passerine species remex VII. begins its
renewal, in fact not before VIII, 1X., & X. are all nearly completely renewed.

The fortunate acquisition of the two wings of a Moor-hen (Gallinula chloropus) in
just such a stage of moult, as well as numerous material of Parrots in the same
condition (notwithstanding the fact that the former belongs to a eutaxic family of
birds), shows that in these birds (a fact in which they all agree) i¢ invariably is the
cubital remex LX. with which their moult begins first on this portion of the wing.

Moreover, an examination by Pycraft (39) fig. 4, pl. 14, of the wing of a young
fowl, convinces me that the “ eutaxy” of the Galline—and probably all those more
primitive groups of birds which compose Mr. Pycraft’s list of eutaxic forms (see p. 248,
l. c.}—is morphologically not the same ‘“ eutaxy ” as that of the Passeres.

The constancy with which in diastataxic wings moult sets in first with cubital
remex IX., by commencing the renewal in an inward direction of the proximal
Group I., against the commencement in the latter with remex VIII. of the Passerine
mode, legitimately points to the assumption that these two quills are morphologically
identical with one another, and that the cubital remex V., where it is present in such
eutaxic forms as the Galline and similar birds other than Passerine, is the original
remex V. still retained by them.

The following scheme will further express my meaning :—

Scheme for right side of Wings.

Group IT. Group III. Group I.
: = AS > & SD [fF +
Galline eutaty .......... (0) t 2 3 4 5 6 uo 8 9 a,

Numerical figures of cubital
WME oo oooneacecnos

| (cam. mS) iy Ii, 1G, IN, We Wah i yaad dx:

Le

Passerine cutary.......... (0) i 2 3 4 0 5 6 G3 @ © Cub)
RP ey) Nn Sy ee
Group II. Group III. Group I.

MR. E. DEGEN ON ECDYSIS. 405

Whether cubital remex V. in the Passerine type of eutaxy is really a member of the
distal or of the middle group cannot be determined positively by means of the present
material ; but it will in all probability be found to belong to the latter, seeing that it
takes up the moult more frequently from the 6th and not from the 4th. his is only
what may be reasonably expected from a flight-feather which is actually remex VL.,
and numerically only remex V., as in the present species. Of the original remex V.
in the Galline type of eutaxy, there is not much doubt as to its belonging to the
distal group.

It has been suggested (see anted, p. 401) that the inner section of metacarpo-
digitals, at present situated on the combined metacarpal bones—on account of their
eminently “digital” character,—were elements originally belonging to the digital
phalanges of digit II]. Since we have found in our former “ proto-metacarpal digitals”
(cubital group II.) the true original metacarpal elements belonging to the metacarpal
bone of the latter digit, we see that this distribution leaves us minus a similar
equivalent for the metacarpal bone of digit IL.

From this the question arises as to what has become of this series, or are they really
anywhere at all ?

The answer to it is not so obscure, and is one to which Goodchild, Wray, and
Pycraft have contributed.

The survivors of this set of feathers are present still in the diastataxic wing, and the
older forms of the eutaxic birds, in the shape of that enigma of a part-series, which is
situated on the distal portion of the forearm known as the ‘ intercalary row.” In the
majority of those birds this row consists of from 5-6 feathers, but their number is
reduced to 4in some. If they are not actually the aborted flight-feathers themselves
(as I suspect them to be, from the fact that in the specimen of a young Parrot—vide
text-figure 2, p. 364,—contrary to the presence of sessile neossoptiles for all the other
covert-feathers, the latter are, curiously enough, absent on both sides) they are at least
the major coverts of the entirely suppressed remiges to which they belonged, and
which are the set of feathers to be yet accounted for.

This latter supposition would constitute a case of ‘‘ apoptilism ” for the whole series,
the same as applies to that of the Parapterum (Degen, 16). Of their pterylo-genetic
relationship to the other covert-series on the dorsum, I would refer to Goodchild (27),
in whose drawings they are marked by the letter C. Goodchild has found them to be
such excellent landmarks for the determination of the rows that the following quotation
from his paper gives a sufficient idea as to their value for further collateral evidence.
This is what he says on p. 189, 7. ¢. :—

“Tn the type of wing-feathers prevailing throughout all, or nearly all, the rest of the
Psittacide (in speaking of an additional row of backward-lapping wing-feathers in
Melopsittacus) an additional modification may be observed. The row of feathers

a3) 1b) 2

406 MR. 8. DEGEN ON ECDYSIS.

coming on next above the greater coverts, indicated by the letter C (intercalary row)
in the following diagram, is seen to consist of a series numbering generally five or six,
which are confined to the distal areas of the cubital region, and form a distinct and
separate series from the feathers that extend across the median area. They correspond
in relative position to the upper wing-coverts (t.m.) in the manual region of the wing’ ',
&e. And further on :-—‘‘'The feathers referred to often form a conspicuous feature on
the wing of the living bird, as they are frequently arranged in such a manner that the
shafts of three or more of the feathers are in a line. The proximal edges of the
feathers are generally as firm as those on the opposite side}, and, as a consequence,
the whole series slides between the feathers next them on the proximal side in much
the same way as the blade of a lancet closes in its sheath,” &c.

Wray (46) also drew attention to this set of feathers, and after rectifying in his
paper a few incongruities which arose out of Goodchild’s nomenciature for the
erouping of portions of the series on the wrist, dismisses the subject (p. 390, /. c.) with
the following remark :—

‘Grouping the feathers according to their insertion, and remembering the conditions
of folding which must occur on the wrist, the observations of Goodchild give the most
complete view of this subject we have.”

It is in Pycraft’s excellent thesis (39) that the greatest amount of significance
as yet attached to the presence—better expressed appearance—of this set of flight-
feathers called the ‘‘ intercalary row” has been most signally pointed out. But how
much the introduction of this element became responsible in the ‘shifting process ”
(chiefly transverse) of all the rows of the distal portion on the forearm, with its
consequent “ faulting,” a glance at the drawing of his own preparation, of the nestling
Lomvia troile (ef. fig. 2, p. 243, U. ¢.), suffices to show. He thus lucidly describes it :—

“The disturbance is much more obvious in the row of papilla immediately above
the remiges—the rudimentary major coverts 1-5. These have become distinctly
separated from the rest of the row proximad of this point. The disturbance of the
rows preaxial to this of the major coverts is barely perceptible. There is yet no
intercalary row” 1.

Why, in spite of the impendingly disturbing influence they exert at this critical
stage, he never so much as attributed to them the real cause of the general disturbance
which his later stage (of the above figure mentioned) so clearly demonstrates, seems
incomprehensible now, although clearly capable of explanation. ‘The reason is that
he connected them—upon their sudden appearance—embryo-genetically with the
members of the rows of either the Medians, or those above the latter, e. g. the Minors,
entertaining even some slight doubts about their serial value as regards the latter's

first or second row; instead of treating them as the real cause which separates the

1 These ztalics are mine.

MR. E. DEGEN ON ECDYSIS. 407

Medians from the Minors between which they wedge themselves in. With regard to
the unsteady location of this intercalary row, in describing on p. 242 (J. c.) the two
different stages of the wing of a Lapwing (Vanellus cristatus, pl. 14. figs. 1 & 2) he
says :—‘‘ It is of interest to note that the downward shifting in this case must have
been but slight, as the intercalary is the 2nd and not the 3rd row of coverts |, as was the
case in the typical wing described on p. 239.”

That there is still another peculiarity which attaches to this row seems almost a
possibility, though not sufficiently clear as yet. It is that their position as regards
the Parrots is undoubtedly immediately above the major coverts; this is confirmed by
Goodchild; whereas, to judge from Pycraft’s well-executed drawing of the wing of the
young fowl and that of the Lomvia troile, they are unmistakably placed above the
medians. I have no doubt about this interpretation as being correct also. But it
seems to suggest one thing, and that is, that they originally wedged themselves in
between different rows in different groups of birds, sometimes above, sometimes below
the medians.

Their appearance takes place at a time when both the wing-membrane and the
bones are still very plastic. While in this condition, the contact of the flight-feathers
with the latter is much less intimate as far back as the region of cubital V., to which
point hardly any impressions of the contact of the remiges with the ulna can be found.
It is only proximally from this point that the bone shows traces of their contact in
the shape of sockets consisting of pits and tubercles, which are retained throughout
all the moults, and which are the outcome of the early fixtures of the remiges on the
posterior portion of the ulna.

If the feathers composing the group of intercalaries were derived from the minor
series, the order of their renewal should correspond with these latter, which is an
outward one. Such, however, is not the case, as seen in a specimen of a Parrakeet
(Platycercus eximius) in my collection, and dated from March 4, which shows this
particular stage of moult. In this the renewal proceeds in the same inward direction
as do the flight-feathers, their major and median coverts,—all belonging to the distal
group. On its right-side wing the 3rd, 4th, and dth, or most proximally situated
feathers of this intercalary row, are to be seen in successive stages of growth in the
numerical order quoted; whilst the 2nd and Ist respectively, or more distal ones, show
unmistakable signs of their having quite recently attained full development. On the
wing of the other side, this stage of moult is slightly more in advance, the 6th or last
feather being in process of renewal only.

A specimen of a Musk Lorrikeet (Glossopsittacus concinnus) also shows the same
arrangement. In consequence of this fact, the significance of flight-feathers as an
additional integer requires to be placed upon this set of feathers, similar to the

1 These italics are mine.

408 MR. E. DEGEN ON ECDYSIS.

remiges I.-IV., with the further definition, however, of a former “ metacarpal ”
derivation.

The following scheme will be found to supplement the original distribution of the
flight-feather elements on the fore limb of the ancestral bird, according to the evidence
adduced in its favour through this work. It represents the left-side wing.

Revised Scheme for the Derivation of the Flight-feathers from the Tetradactyle
Ancestral Form of Birds.

Proto-metacarpo-digitals = Hypo-metacarpo-digitals =
Frieur-rearners or PHALaNcnaL OntG1n. Fricgur-Fratuers oF Muracarrat OriGin.
Digit I.
Suppressed (lost). Present Penne pollicis [V.-I.
Digit II.
Present Metacarpo-digitals XI.—VI. Present Intercalary row I.-VI.
Digit III.
Present Metacarpo-digitals V.—I. Present Cubital Group IT., Secondary Remiges (0) I-LY.
Digit IV.
Present Cubital Group III., Secondary Remiges V.- Present Cubital Group I., Secondary Remiges VIII.-X.
WAnr —Cubiti veri X1.-«.

Direction oF Movutr.

From the foregoing scheme it may be observed that there are no flight-feather
equivalents allotted to the phalangeal portion of Digit I., in which part they figure as
“ suppressed.”

Such a condition is quite conceivable and in perfect accord with suppression of
quills in other portions, as, for instance, the reduction on the extreme phalanx of the
second finger from 12 to 11 (Podicepide, Pelargi, &c.), and from 11 to 10 and 9 in
Passeres (Gadow, 21, pp. 656 &c.). This tendency towards a part-suppression, if
carried further, would have the effect of leading to total apoptilism. It, moreover,
must have proceeded contemporaneously with the feathering of the forearm and was
still in progress after, as is evidenced in the Passeres, where it has reached the
present climax in the Oscines proper.

Considering the genealogical relative shortness of Digit I., coupled with the fact of
a still greater reduction of size in the present forms of birds to one compound element,
there is a strong probability existing that, during the course of the fusion of the
phalangeal segments of this digit with its originally independent metacarpal bone,

MR. E. DEGEN ON ECDYSIS. 409

they were stripped off one after the other as in the case of the ‘“‘ Remicle” and other
diminutive terminal coverts. A likely procedure for feathers which at no time could
have been of any considerable size, and certainly not more in number than three at
the most.

The moult of the ‘Penne pollicis,” moreover, synchronizing with that of Metacarpo-
digitals VI.—X. and Cubitals I-IV. (see Table VI.), is by no means an unimportant
item for the argument that in their retrograde movement they were obstructed by the

?

position which these latter, together with the “intercalaries” (as representing the
metacarpal equivalents for Digit II.), had early taken up on the distal portion of
the cubitus.

Finally, if the present inquiry into the moult of the individual bird, which, however,
reflects all the phylogenetic conditions inherent to the Class asa whole (except perhaps
the Spheniscidz), has not thrown any further light upon the question as to whether
“ diastataxy ” is due to either the hypothetical adsence of a remex or the assumed
presence, consequent upon the “ shifting” process alone, as summarized by Pycraft (in
his paragraph (1) p. 241, /. ¢.), it should at least have contributed materially towards
the outstanding answer of the first part of the latter author’s paragraph (3)—“ The
cause of this shifting is still a matter for investigation”; and also to the second part
of the same sentence—“ it is possibly due to a slight secondary lengthening of the
forearm.”

This latter interpretation does not seem to gather strength, especially when we
perceive the ample manner in which the “ moult” supplies the proof that ‘ faulting” is
not confined alone to diastataxic wings, but takes place, though in inferior degree, in
the short-armed eutaxic forms of birds, such as the Passeres.

My sincere thanks are due to the following gentlemen :—

To Mr. J. Orme, of the Victorian Railways, Murchison East, Victoria, Australia,
who by his disinterestedness in supplying me with the specimens has so materially
aided me in my task.

To Dr. R. Bowdler Sharpe, of the British Museum (Nat. Hist.), for his interest
shown in its progress and encouraging me in its completion.

To Dr. Chalmers Mitchell, F.Z.S., F.L.S., &c., for his valuable advice and sugges-
tions made on the form of this memoir and its preparation for publication.

To C. Davies Sherborn, Esq., F.Z.S., for his generous act of revising the MS.

To the Editor, for the facilities given me in kindly placing at my disposal the use
of the Library of the Zoological Society.

Also to the Staff of the Society’s Library and the Publication Department, for the
ever-courteous manner in which my wants were met.

410

—
at
—

(12)

MR. E. DEGEN ON ECDYSIS.

X.— BIBLIOGRAPHY.

Arten, J. A.—® Alleged Changes of Colour in the Feathers of Birds without Moulting,” Bull.
Am. Mus. Nat. Hist. art. 3, vol. vill. 1896, pp. 13-42.

Aurum, B.— Ueber den Bau der Federn als Grund ihrer Iarbung, ein Beitrag zur Pterologie,”
Journ. fiir Ornithologie, ii. Jahrg. 1854, art. 1 (Erinnerungschrift), pp. xix—xxxy.

Breppanrp, F. E., M.A., F.R.S.—‘ The Structure and Classification of Birds.’ London, 1898
(Longman, Green, & Co.).

Bryru, Evwarp.—‘ On the Reconciliation of certain apparent Discrepancies observable in
the Mode in which the Seasonal and Progressive Changes of Colour are effected in the
Fur of Mammalians and Feathers of Birds ; with various Observations on Moulting,”
Magazine of Natural History (Charlesworth’s), vol. i. (May 1837), art. 9, pp. 259-281 ;
continued June 1837, art. 3, pp. 800-3810.

Bick, Prepvicrr.—“ Ausfallen der Mauser bei einem Vogel in der Gefangenschaft,” Journ. f.
Ornith. i. Jahrg. 1853, i. Heft, No. 3, p. 267.

Breum, Cur. Lupwic.—“ Bemerkungen tiber den Federnwechsel und das Sich-Ausfirben
des Gefieders’’ (Bericht an die Ornithologen Versammlung zu Halberstadt), Journ. f.
Ornith., Extraheft, i. Jahrg. 1853, Art. 3, pp. xxiv &c.

Breum, Cur. Lupwic.—‘ Die Mauser der jungen Raubyogel und der Uebergang ikres
Jugendkleides in das Ausgefarbte,’ Journ. f. Ornith. i. Jahrg. 1853, in. Heft, No. 3,
pp. 196 &e.

Breum, Cur. Lupwic.—Ibid. Continuation, v. Heft, No.5, pp. 343-246,

Breum, Cur. Lupwic.— Gegen Schlegel’s Meinung tiber die Verfarbung des Gefieders,”
ibid. p. 347.

Breum, Cur. Lupwic.—< Verfarbung und Federnwechsel der Huropaischen Seeschwalben,”
ibid. i. Jahrg. 1854, iv. Heft, No. 10, pp. 317-822.

Cuappourne, Arruur P., M.D.—< The Spring Plumage of the Bobolink (Dolichonyx oryzi-
vorus), with Remarks on the ‘Colour-change’ and ‘ Moulting,’ ” The Auk, vol. xiv. no. 2,
April 1897, pp. 111-154.

Cuatmers Mircuety, P., M.A., F.Z.S., F.L.S.—< On so-called ‘ Quintocubitalism’ in the
Wing of Birds; with special reference to the Columbe, and Notes on Anatomy,” Journ.
Linn. Soc. Lond., Zool. vol. xxvii. no. 175, July 1, 1899, pp. 210-236, pls. 12 & 18.

Cuapman, F’. M.—< The Changes of Plumages in the Dunlin and Sanderling,” Bull. Am. Mus.

_ Nat. Hist. vol. vii. art. 1, 1896, pp. 1-8.

Cuapman, F. M.—< On the Changes of Plumage in the Snowflake (Plectrophenax nivalis) ,”
ibid. art. 2, pp. 9 &e.

Cuarman, F. M.—* Remarks on the Spring Moult of the Bobolink,” The Auk, vol. xiv. 1897,
pp. 150-154.

Drcen, Epwarp.—* On some of the Main Features in the Evolution of the Bird’s Wing,”
Bull. Brit. Orn. Club, vol. ii. 1894, pp. i-xxxiul, pl. 1.

Dwicut, JonatHan.—* The Sequence of Plumages and Molts of the Passerine Birds of New
York,” Am. Ac. Sci. New York, vol. xiii. 1900, pp. 87 &c., with plates.

Dwicur, Jonaruan, Jun., M.D.—‘‘The Sequence of Molts and Plumages of the ‘ Laridz ”
(Gulls and Terns),” The Auk, vo]. xvii. Jan. 1901, no. 1, pp. 49-63.

MR. E. DEGEN ON ECDYSIS. 41]

(19) Fatro, Dr. Vicror.—“ Des Diverses Modifications dans les Formes et la Coloration des
Plumes,” Mém. Soc. Phys. d’Hist. Nat. Genéve, tome xviii. 1866, pp. 250-295.

(20) Gapow, Dr. Hans.—“ On the Colour of Feathers as affected by their Structure,” Proc. Zool.
Soc. Lond. 1882, pp. 409-421, pls. xxvii., xxviii.

(21) Gapow, Dr. Hans.—“ Remarks on the Numbers and on the Phylogenetic Development of
the Remiges of Birds,” ibid. 1888, pp. 655-667, parts i. & ii.

(22) Girxe, H.—“ Einige Beobachtungen iiber Federnwechsel durch Verfarbung ohne Mauser,”
Journ. f. Ornith. ii. Jahrg. 1854, iv. Heft, No. 10, pp. 321 &e.

(23) Grrse, Z.—“ Sur les Plumes du Vol et leur Mue,” Bull. Soc. Zool. France, 1877, tome ii.
pp. 289-290.

(24) Grocer, Dr. C. W. L.—*< Bemerkungen iiber den Aufsatz Martin’s,” Journ. f. Ornith. i. Jahrg.
1853, i. Heft, No. 1, pp. 19-28.

(25) Grocer, Dr. C. W. L.— Zur Erklirung der Verfarbung des Gefieders,” ibid. iv. Heft, No. 4,
pp. 269-275.

(26) Grocer, Dr. C. W. L.—Sollten Kraniche wohl eine besondere Sommertracht haben ? ”
ibid. iv. Jahrg. 1856, v. Heft, pp. 392-894.

(27) Gooncutty, J. G., F.Z.S., F.G.S.—* Observations on the Disposition of the Cubital Coverts
in Birds,” Proc. Zool. Soc. Lond. 1886, pp. 184-203.

(28) Hester, AA—“Ornithologische Beobachtungen,” Journ. f. Ornith. ii. Jahrg. 1854, ii. Heft,
No. 8, pp. 185 &c., 286.

(29) Hoxtanp, Turovor.—“ Zur Entwickelungsgeschichte der Federn,” Journ. f. Ornith. viii. Jahrg.
1860, v. Heft, No. 47, pp. 341-347 ; ibid. continuation, vi. Heft, No. 48, pp. 432-442,
pl.1. figs. 1-11.

(30) Homeynr, HE. von.—“ Feder- und Farbenwechsel,”’ ibid. iii. Jahrg. 1855, iv. Heft, No. 16,
p- 347.

(30a) Homeynr, E. von.— Ein ferneres Wort iiber das Ausfarben,” ibid. ii. Heft, No. 14, 1854,
pp. 113-117.

(31) Homuyerr, E. von—* Noch ein Wort iiber die Verfarbung,” ibid. iv. Jahrg. 1856, ii. Heft,
No. 20, pp. 129-182.

(32) Marrin, Lrororp.—‘‘ Ueber den Farbenwechsel bei Muscicapa collaris, M. atricapiila, und
M. parva im Frihlings,” ibid. 1. Jahrg. 1853, 1. Heft, No. 1, pp. 16-18.

See also comment on this by Gloger (¢bid. p. 19).

(33) Martin, Lrorotp.— Zur Verfarbung des Gefieders, namentlich bei Anas nigra,” ibid.
iv. Heft, No. 4, pp. 208 &c.

(34) Meves, W.—‘ Ueber die Farbenveranderung der Vogel durch und ohne Mauser,” ibid.
ii. Jahrg. 1855, ii. Heft, No. 15, pp. 280 &e. Taf. ii. & i.

(35) Muituais, Joun Guitxe, F.Z.S.—< On the Change of Birds to Spring Plumage without a
Moult,” The Ibis, 7th ser. vol. 11. 1896, art. 40, pp. 451-457, pl. x.

(36) Mutruur, Dr. Baron v.—“ Ueber den Farbenwechsel der Vogel,” Journ. f. Ornith. i. Jahre.
1853, v. Heft, No. 5, pp. 327-329.

(37) Nirzscu, Curistian Lupwic.—< Pterylography.” ‘Translated by Ph. Lutley Sclater, M.A.,
Ph.D., F.R.S., for the Ray Society of London, 1867.

(38) Pycrarr, W. P.—< A Contribution to the Pterylography of Birds’ Wings,” Trans. Leicester
Lit. & Phil. Soc. vol. ii. part 3, April 1890, pp. 1-22.

VOL. XVI.—ParT vill. No. 9.—Jd/ay, 1903. 3

ke
—

e

MR. E. DEGEN ON ECDYSIS.

Lo

(39) Pyerarr, W. P., A.L.S.—€ Some Facts concerning the so-called ‘ Aquintocubitalism’ in the
Bird’s Wing,” Journ. Linn. Soc. Lond., Zool. vol. xxvii. July 1, 1899, pp. 236-256,
pls. 14-16.

40) Scurucer, Dr. Hermann.— Sendschreiben an die am 6%" Julius 1852 zu Altenburg versam-
melten Naturforscher,’” Naumannia, 1852, ii. Bd. 11. Heft, No. 1, pp. 19-24 &e.

(41) Scunecer, Dr. Hermann.—“ Verfirbung das Gefieders,” Journ. f. Ornith. i, Jahrg. 185%,
i. Heft, No. 1, p. 67.

(42) Scuiecer, Dr. Hermann.—‘ Ueber das Wachsthum und die Farbenveranderungen der
Federn der Vogel,” zdid. iii. Jahrg. 1855, 1. Heft, No. 19, p. 255.

(43) Sunprvatz, C. J.— Ueber die Fliigel der Vogel,” ibid. ii. Jahrg. 1855, ii. Heft, No. 14,
pp. 118-163.

(44) Wirrmer Sronr.— The Molting of Birds, with special reference to the Plumages of the
smaller Land-Birds of Nastern North America,” Proc. Acad. Nat. Sc. Philadelphia, 1896,
pp. 108-127.

(45) Wray, R. S., B.Se.—* Note on a Vestigial Structure in the Adult Ostrich representing tlie
Distal Phalanges of Digit III.,’ Proc. Zool. Soc. Lond. 1887, pp. 283 & 284, text-
figures ]—4,

(46) Wray, R. 8., B.Sc— On some Points in the Morphology of the Wings of Birds,” iid.
pp. 343-355, pls. xxix.—-xxxil.

XI.—EXPLANATION OF PLATES XXXVI-XXXVIII.

The Roman figures placed at the head of each diagram denote the numerical order of the flight-
feathers, as counted from the wrist-joint, outwards for the digital portion, inwards for the cubital
portion of the left and right wing respectively.

The broader dark vertical bars indicate those remiges which are in progress of moult.

The symbol 0, placed over the bar indicated by dots only, signifies this particular remex is
shed off.

The numbers placed immediately above the bars express the actual length of growth of the remex
represented by that bar, in millimetres.

The proportionate growth of the remiges in moult may be read off on the scale from 0-100
(100 standing for full growth), which is provided for each diagram.

The small letters beneath each diagram indicate the chronological appearance of the remiges on
the two portions of the wing—plain letters for the metacarpo-digital ; with a dash, thus ’, for the
cubital portion.

SE OO

414 MR. E. DEGEN ON ECDYSIS.

PLATE XXXVI.

Diacram A. Showing moult of metacarpo-digital remiges I. and II., or @ and 4, also
their corresponding equivalents VIII. and IX., or a, b', on the cubital
portion.

Diacram B. Ilustrates the anomalous case peculiar to the moult of metacarpo. digitals
IIl., 1V., and V., or c, d, and e, a triplet of remiges which has no corre-
sponding equivalent on the cubital portion at this stage of development.

Diagram C. Stage of development of previous diagram in a more advanced condition
of moult, besides which remex VI. or f, or the next in turn, is shown.

On the cubital portion of the left side are seen also the remiges I., X., and
VIL., lettered f', f", and f" respectively, the triplet of flight-feathers which
restores the temporary asymmetry formed by c, d, and e on the hand-portion,
as shown in diagram B.

Dracram D. Showing moult of metacarpo-digital VII., or g. The moult of its corre-
sponding remex II., or g’, is indicated at this stage by being shed off. This
stage forms one of transition between f, f’, f", f"" to that of g, g’.

D

Bl

D

ic)

Left Side Wing.

SPECIMEN No. 1. ad.é@

METACARPO-DIGITALS. CUBITALS.
X Vx. VIILVI. VE. OV. WW. MM TM th. IV. ¥._ YI. Yi. Vill. 1X. X.
imal [| Joftosiio) —f 7 [| [90/70] |
ear aa i =aiimeal ail eclicefoaaloanl aa
ma | Pes a A
ol | | | |
al ir] it al Ia roan
} | ie SSS eee
| | 1 | |
| fhe death te
| [a | 1a | |
mf oll f) |
| [a Poll
I | ' Tal
1] |
| Ee | he
i i | | | | a
(c) b a a’ b’

METACARPO-DIGITALS.

Stage of a and b, and a,b’

1B IB EW No VE

Nov. 5.

SPECIMEN No.

CUBITALS.

Vil. VII. 1X. X.

X. WX. VIN VIL. VI. oY. WW. WW. WT
T

25|80|120| |

55/15

| 10

i

Stage c, d, and e.

je da c)

(No equivalent on this portion.)

Nov. 14.

XK WILVIL WY. WML Te.
[ |7o]

Trim. Lo. Soe Vol XVI I¢, XXXVT.

Right Side Wing.

CUBITALS.

METACARPO-DIGITALS.

70

Iucnle 0

1 MW. ¥. Vi. WLW IX. X
ssj90jo| | | a

|
]
|

—

= 100

Stage of a, b.

3. juv.@

CUBITALS.

a b (c)
and a’, b.

METACARPO-DIGITALS.
11 TW WV. ¥. Vi. VU VII IX. X.

X. 1K WLW. WV. WW. WW.
f 30 T

65

+! )

| res|95 145

L

eee 10

tH

L

1

= I) 1 100

(No equivalent on this portion.)

SPECIMEN No. 7. ad.d

METACARPO-DIGITALS. CUBITALS.
XIX. VIL VI. WV. IW. JI. Wd. I. JL WW. V. Vi. VU. VII IX. X.
80 [165 60] 25 25
()
te 10 F i—
| 20
30 al
He 40 ate
50 +—
IL 60
70
80 IL)
90
a 100 |, FF -

Stage of f, and f; f,’ f”

Nov. 19.

CUBITALS.

X. 0X. VI VI WEY. IW. TM. IT.

(cy ae)
Stage ofc, d, e.

METACARPO-DIGITALS.

45

I. Wl. TW. VY. VI. VOL VIN. TX. X.
160] 75

II

(imperfect for f”and
see left side wing.)

SPECIMEN No. 10. aa.d

METACARPO-DIGITALS. CUBITALS.

X. IX. VIN. VIL VI. V. WW. TM. 1. I. I WL IV. ¥. Vi. VIL VIL IX. X.
20 140 9 (9912 0 | 75 0

I 10 : anes :

20 | a Oa 1

a ’ | ‘

40 - ! : :

50 |} 1" : :

| 60 J | ‘ J

| | 70 ' i u

Le 4 80 1 ‘ | 4

' ’ fa

_| | a | f) ail lo
gf f’ (g’) (k) (£”) (f”)

gen, del

Stage in transition for f, f/f” f/”and g, g’

Nov. 28.

ih

CUBITALS.

IX. VIII. VI. VI. V. WW. UM. I. 1.

f
f” Stage of f, f’

METACARPO-DIGITALS.
1. MU 1. ¥. WE. VU. VI IX. X.
T

25 95

4

|

wml mlm me mle le ie KO

90

!| 100

145
|
ta]

£”

Led =
a @)f
Stage of f, f’ f//and f’”

cme
Transition to g and (g’).

Bale & Damelsson, L‘*

DIAGRAMS ILLUSTRATING THE MOULT OF THE REMIGES IN
GYMNORHINA TIBICEN.

7

a ee

SOOO VIL,”

416 MR. E. DEGEN ON ECDYSIS.

PLATE XXXVII.

Diagram EK. Stage for moult of metacarpo-digital VII., or g, and cubital remex IL.,
or g', repeated. Here the conditions are reversed to those of diagram D.
In this specimen. it is the hand-portion which is in arrear, while the cubital
portion is in advance.

Diagram F. Intermediate phase of moult for metacarpo-digital remex VIII., or h
(in arrear on both wings in this specimen), and its equivalent on the cubital
portion remex III., or h’. This forms a case of transition from g to h.

Discram G. Showing stage of moult for /, hand-portion, and h’, cubital portion, in
perfectly normal condition. Also early indication for the moult of metacarpo-
digital IX., or 7, the next stage, on the left-side wing.

Diacram H. Shows the moult for metacarpo-digital remex [X., or ¢ (abnormally in
arrear in this specimen), and its equivalent remex IV., or 7’, on the cubitus.
Stage of transition from h to 7.

Trams, Loo SocVol XVI IE, XXXVI.

Left Side Wing. Right Side Wing.
SPECIMEN Ne. 11. juv.?
BE METACARPO-DIGITALS. CUBITALS. iDEe, Eb CUBITALS. METACARPO-DIGITALS.
X. IK. VWI VV. WW. WL IL I. IL UL W. VY. Wi. VIL VII, XX. VILVIL VOY. WW. TI Ie. {. I ML WW. ¥. VL VL VII. X.
| 0 [115 o 15/55 100) | [45] |95) 50 | 115] 0
4 T 7 fil | 1
oh 2 een 3
U 30 | ae
40 isa
] 60 | | 0
! 60 =ll : | | |
i] 70 (eal | | | i]
1 a 1
1 50 | l t
1 n
| | 100 E =. | =
(g) fy ey (g)
Stage supplementing development of g, g’ Stage of g, g/ supplemented.
SPECIMEN No. 16. juv.é
PF METACARPO-DIGITALS. CUBITALS. Dec. 19. CUBITALS. METACARPO-DIGITALS.
C GNTIEVTL WE NE We MIG Tie It I. Wl. IV. ¥. Vi. Vil. VII. IX. X. XIX. VWI. Vi. V. WW. UL OW. LU WW. ¥. Vi VO. Vi. 1X. Xx.
400/185] | 9 | {l20|80 60 50 20] /50 | [95 |115|125) 6 g0|100
|
10 + 4 10 4
20 20
30 | 30 |
| 40 40 z
| 50 } 50
60 60
70 a i a | 70 -
80 2 80 |
90 | 90 Hees
100 | ! 00)
g emhy hig &
Stage of transition from g. to (h)h’ Transition from stage g. g’ to (h )h’
SPECIMEN No. 14. juv.? e
G METACARPO-DIGITALS. CUBITALS. Dee. 11. CUBITALS. METACARPO-DIGITALS.
XX. VILVIL VW. WW. MI. Lo WW. ¥. VE VIL YI Ix. x. X. IX VLVI. Wi. oY. WV. I IL so 1. Wl. WL WV. ¥. Vi. VIL VII. IX. X.
0] 5 |15 38 40 lol =
At a 6 g 45 45 5 115] 5
10 ; 10
20 : 20
; 30 30
; 40 t ! 40
650 ! 50
! 60 d 60
! 70 | L! 70
i] | '
80 | lit | 80 pot
' | | | !
: 90 oo } | 90
| 100 pee | ead EI (0 100
@ b W iy h
Stage of h, h’ Stage of h, hi.
SPECIMEN No. 17. ad.é
WoO2OC«sMiESTACARPO-DIGITALS. CUBITALS. Jan. 1. CUBITALS. METACARPO-DIGITALS.
XIX. WIV. VI. Y. TW. ML IL IIL M1. ¥. VI. VIL VIL IX. X. X. 1X. VWI. WY WY. I 1 IIL MW. YW VU. VI IX. x.
65 [150/115 100/25 40 lL] el 180] 65
io) (0)
10 10
20 4 20
a 30 30
; 40 | 40
60 = 50
=I 60 60
; | 70 70
| 80 } 80
IF 90 90 |
i 1 |
100 I
h hb’ i’ TH 100 =
Stage of transition for development of h, h’ and (i) in part i’ Transition from stage h, bh’, to (i) i’
E. Degen, del Bale & Damelsson, Lt?

DIAGRAMS ILLUSTRATING THE MOULT OF THE REMIGES IN
GYMNORHINA TIBICEN .

PLATE XXXVIIL

418 MR. E. DEGEN ON ECDYSIS.

PLATE XXXVIII.

Diagram J. Moult of remex IX., or 7, on the hand-portion, and its corresponding
remex IV. for the cubital portion, in a perfectly normal condition for the
left-side, imperfect for the right-side wing.

Diagram K. Represents the stage for the development of metacarpo-digital X., or 4,
and that of its equivalent for the cubital remex VI., or #’.

Diacram L. Shows the final stage of the moult for the flight-feathers, or that of
cubital remex V., and lettered /', which under normal conditions finds no
equivalent on the hand-portion. It further supplements stage /, #' for the
left-side wing only, being in arrear of moult for these on the right side.

Diagram M. Specimen in arrear for the moult of metacarpo-digital X. on both sides,
but otherwise showing final stage, or that of cubital V., to advantage.

Left Side Wing.

Tram. £00. SooVol VISE. XXAVIL.

Right Side Wing.

SPECIMEN No. 21. ad.d

METACARPO-DIGITALS. CUBITALS.

XO 1K VII VY. WL i. . 1 IL. W. ¥. Vi WL VI IX. X.
0 [125197| ml | | al [hao |
197] | |
! 10
[ee | 20
i |
f 1 t 30
| 40
! | 60
! 60
! | 70
1 |
1 |} go
90
OI 100 L
(kK) i

Stage of i and i’

Jan. 29.

SPECIMEN No.

METACARPO-DIGITALS. CUBITALS.

TM. WLW. ¥. We VIL VIL IX. X

65

140)

X. IX. VIL VI. VIL OV. WW. MT.
|
|

! 80

100 |

Stage of k and k’

Feb 18.

SPECIMEN No.

ME TACARPO-DIGITALS. CUBITALS.

X. 1X. VII. VII. VI
90 [150]

Vv. W. WE 1. IM TM, iv. Y. We YI VI. IX. X.

110/15 |

To

90
100

Stage of 1’ (no equivalent on hand portion).

SPECIMEN No.

METACARPO-DIGITALS. CUBITALS.

XK VIVIL VV. WW, WW WTI. WV. VD. VIN KX
60150] | || |_| [90]

|
|
|
|

| 90
!100 |

Supplementary stage of 1’ (final development)
spec. in arrear for k, complete for k’

Degen, del

DIAGRAMS ILLUSTRATING THE MOULT OF THE

March 4.

Feb. 18.

CUBITALS. METACARPO-DIGITALS.

X. 1K. VILLI. WV. WW. ML.
mal aa j70] | ry ee

oo | 20

LW MW. ¥. VE WA. VIL IK. X.
(200150) 10
i

|

100

Stage of i (imperfect for i

25. ad.d

CUBITALS. METACARPO-DIGITALS.

IW. WL OW. ¥. VE Vil VI. IX. X.

X. 1K. VILVIL VEY. WM IL 1.
] 135|65

90 |
100

Gi) k
Stage of k, k’

26. add
CUBITALS. METACARPO-DIGITALS.
X. IX. VIN. VI. VY. WW. MTT. J. IL WL 1. V2 Vi. VOL VIL IX. X.
| ] [as fis] | | |

i]

Stage of l‘(no equivalent on hand portion).

24. ad.d

CUBITALS. METACARPO-DIGITALS.

X. UX. VIII. VI. WWW. TW. We.

I. WL WL W.-Y. WL VU. VU. IX. X.
] |160|35

T
|
|
at

|
|
T
|
=I
|
|

100

ee
Stage of I’ (further development) in arrear for k
complete for k’

Bale & Damelsson, L*?

REMIGES IN

GYMNORHINA TIBICEN.

41¢

LIST OF THE PAPERS CONTAINED IN VOL. XVI.

Bepparp, Frank E,, M.A., F.R.S., Prosector
and Vice-Secretary of the Society.
Contribution towards a Knowledge of the
Osteology of the Pigmy Whale (Neo-
balena marginata)

Bovuteneer, G. A., F.R.S., F.Z.S.

Third Contribution to the Ichthyology of
Lake Tanganyika.—Report on the Col-
lection of Fishes made by Mr. J. E. 8.
Moore in Lakes Tanganyika and Kivu
during his Second Expedition, 1899-
1900

Bravy, Groren Srewarpson, M.D., LL.D., D.Sc.,
F.R.S., C.M.Z.8.

On new or imperfectly-known Ostracoda,
chiefly from a Collection in the Zoological
Museum, Copenhagen

Boverrr, J. §., M.A., F.Z.8., Trinity College,
Cambridge.

On the Breeding-habits of some West-
African Fishes, with an Account of the
External Features in Development of
Protopterus annectens, and a Description
of the Larva of Polypterus lapradet

On the Structure of the Larval Poly-
IU, ovcnbosavesosoaodundgucpoc

Drern, Epwarp, F.Z.8.

Eedysis, as Morphological Evidence of the
Original Tetradactyle Feathering of the
Bird’s Fore-limb, based especially on
the Perennial Moult in Gymmnorhina

tibicen

VOL. XVI.—ParT vill. No. 10.—May, 1903.

87

137

Howes, G. B., LL.D., F.R.S., and Swriyyerton,
H. H., B.Sc., Marshall Scholar,-R. Coll.
Sci. Lond.

On the Development of the Skeleton of
the Tuatara, Sphenodon punctatus ; with
Remarks on the Egg, on the Hatching,
and on the Hatched Young. (From the
Huxley Research Laboratory.)

Lanxesrer, E. Ray, M.A., LL.D., F.B.S., F.Z.S.,
Director of the Natural History De-
partments of the British Museum, Cor-
respondent of the Institute of France.

On Okapia, a new Genus of Giraffida,
from Central Africa

Moper, Geo. P., A.R.C.S. Lond., F.Z.S., Lec-
turer on Biology, London School of
Medicine for Women, and Demonstrator
of Biology, London Hospital Medical
School.

On the Myology of the Tongue of Parrots,
with a Classification of the Order, based
upon the Structure of the Tongue

Swinnerton, H. H., B.Sc., Marshall Scholar,
R. Coll. Sci. Lond., and Howes, G. B.,
LL.D., F.R.S.

On the Development of the Skeleton of
the Tuatara, Sphenodon punctatus ; with
Remarks on the Egg, on the Hatching,
and on the Hatched Young. (From the
Huxley Research Laboratory.)

o

YN

Page

279

a) PALL

INDEX OF SPECIES, ETC., IN VOL, XVI.

Acanthias, 50.

Acerina, 156.

Acipenser, 51, 332.

Acrosaurus, 3.

Africa, on the Breeding-habits of some Fishes of
West, 115-186.

Agama, 73.

Aipysurus annulatus, 3.

Alces, 285, 286, 287.

Alestes lemairii, 137.

macrolepidotus, 140, 143.

macrophthalmus, 137, 140, 143.

Amia, 327, 330, 337, 338.

Amphioxus, 51.

Anas nigra, 411.

Anchitherium, 289.

Anoplopterus platychir, 140.

Anser, 261.

Antilocapra, 287, 296, 297.

Aprosmictus, 258, 259.

Apteryx, 33.

Ara, 212, 226, 234, 249, 251, 255, 262, 263, 264.

—— ararauna, 215, 219, 227, 229, 240, 245, 247,
253, 255, 259, 260, 261, 268, 276.

—— macao, 211, 218, 219, 220, 221,.229, 224,
227, 229, 240, 245, 255, 259, 261, 268, 274,
276.

Archeopteryx, 2.

Armadillo, 292, 296.

Ascahabotes fascicularis, 50.

Asprotilapia leptura, 141, 159, 178.

Asterope sp., 199.

brevis, 183.

lichenoides, 180, 206.

oculata, 179, 202.

quadrata, 180.

Auchenoglanis biscutatus, 137, 140, 148.

VOL. XVI.—PaRT vill. No. 11.—J/ay, 1903.

Bairdia hirsuta, 197.

longisetosa, 197, 210.

villosa, 197.

Balena, 87, 89, 91, 93, 94, 95, 99, 101, 102, 103,
104, 105, 106, 107.

—— australis, 94, 95, 96, 98, 101.

marginata, 88, 89.

mysticetus, 98, 101.

(Caperea) antipodarum, 89.
Balenoptera, 90, 93, 94, 95, 96, 99, 101, 102, 103,
104, 105, 106, 107.

huttoni, 95, 96.

-— laticeps, 94.

musculus, 93, 95, 96, 98, 107.
rostrata, 92, 94, 95, 96, 99, 104, 107.
sibbaldi, 94, 96, 99, 104.

Barbus altianalis, 140, 144, 145, 164.
capensis, 144.

kessleri, 145.

—— mariquensis, 145.

platyrhinus, 140, 144, 162.

serrifer, 140, 145, 166.

tropidolepis, 140, 145, 164.

Barilius moorit, 140, 146, 166.

tanganice, 140, 146, 166.
(Pelotrophus) microlepis, 147.

Barita destructor, 396.

strepera, 396.

varia, 396.

Bathybates fasciatus, 141, 153, 172.

ferox, 141, 153.

Beddard, F. E. Contribution towards a Knowledge
of the Osteology of the Pigmy Whale (Neo-
balena marginata), 87-114.

Bolborhynchus, 222, 223, 226, 227, 234, 245, 249,

258, 254, 255, 256, 259, 261, 262, 263, 266.

lineolatus, 222, 231, 242, 278.

2
00

422 INDEX.

Boulenger, G. A. Third Contribution to the Ich-
thyology of Lake Tanganyika.—Report on the
Collection of Fishes made by Mr. J. H. 8.
Moore in Lakes Tanganyika and Kivu during
his Second Uxpedition, 1899-1900, 137-178.

Brady, G. S. On new or imperfectly-known
Ostracoda, chiefly from a Collection in the
Zoological Museum, Copenhagen, 179-210.

Bramatherium, 292, 293, 296.

Brotogerys, 221, 222, 223, 225, 226, 234, 238, 239,
242, 245, 249, 252, 253, 254, 259, 261, 262,
263, 268.

—— pyrrhopterus, 221, 2388, 252, 276.

Buceros, 397.

Budgett, J. §. On the Breeding-habits of some
West-African Fishes, with an Account of the
External Featuresin Development of Protopterus
annectens, and a Description of the Larva of
Polypterus lapradei, 115-136.

——. On the Structure of the Larval Polypterus,
315-346.

Cacatua, 214, 217, 219, 227, 233, 249, 253, 254,

255, 262, 263.

alba, 214, 215, 219, 226, 227, 232, 233, 237,

243, 245, 258, 263, 268.

galerita, 214, 215, 216, 217, 220, 221, 226,

227, 228, 229, 232, 235, 245, 253, 258, 2

261, 262, 263, 268, 272, 274, 276.

leadbeatert, 217, 218, 223, 224, 226, 227, 232,

235, 242, 245, 249, 261, 2638, 268.

roseicapilla, 215, 226, 227, 228, 232, 235, 242,

245, 249, 253, 258, 261, 263, 268, 351.

sulphurea, 214, 218, 226, 227, 233, 237, 253,

254, 258, 261, 268.

triton, 214, 219, 226, 227, 233, 237, 240, 243,

245, 258, 263, 268.

Caica, 226, 227, 234, 243, 245, 249, 253, 254, 261,
263, 264, 266.

leucogaster, 224, 231, 242.

Calamoichthys, 317, 820, 327, 328, 332.

Calopsittacus, 226, 227, 235, 245, 250, 251, 253,

256, 259, 261, 262, 263, 268.

nove-hollandice, 218, 227, 233, 249.

Calyptorhynchus, 217, 227, 243, 245, 249, 250, 2538,

254, 261, 262, 263.

banks, 215, 226, 227, 228, 232, 237, 254,

268.

Calyptorhynchus funereus, 215, 226, 227, 232, 237,
253, 259, 268.

Candonella virescens, 193, 210.

Candonopsis complanata, 196, 210.

Caperea antipodarum, 89.

Capoéta dilloni, 144.

fundulus, 144.

—— tunganice, 140, 143, 144, 162.

—— trutta, 144.

Capra, 287.

egagrus, 302,

Ceratodus, 328.

Certhiola, 212.

Ceryle aleyon, 390.

Chaieleo, 30.

Champsosaurus, 3.

Chauna, 261.

Chelone mydas, 57.

Chenopis atrata, 366.

Chitra, 70.

Chlamydoselache, 329.

Chromis tanganice, 158.

Chrysichthys brachynema, 140, 148, 168.

cranchit, 140, 147, 148.

myriodon, 140, 147.

sharpit, 137.

Chrysotis, 212, 213, 234, 249, 250, 252, 253, 254,

255, 256, 262, 263.

estiva, 219, 226, 230, 235, 245, 253, 259, 261,

268.

leucocephala, 211.

.

ochrocephala, 219, 2:
235, 236, 245, 249, 2: ee
panamensis, 219, 226, 227, 230, 235, 236, 245,
261, 268, 274.

viridigena, 219, 226, 227, 236, 239, 245, 258,
259, 268.

(viridigenalis) viridigena, 229.

Cichla, 156.

Ciconia, 261.

Citharinus gibbosus, 140, 143.

Clarias liocephalus, 140.

robecchii, 140.

Codonocera, gen. noy., 188.

cruenta, 188, 204.

Colius, 397.

Columba domestica, 360.

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INDEX. 425

Concheecia hyalophyllum, 199.

magna, 199.

maxima, 199.

porrecta, 199.

spinirostris, 190, 199.

striata, 190, 199.

Conchecilla lacerta, 199.

Conchecissa cucullata, 179, 191, 199, 208.

imbricata, 199.

Conurus, 234, 249, 250, 252, 263.

cactorum, 220, 226, 227, 230, 234,

242, 245, 253, 254, 255, 262, 268, on a

carolinensis, 212, 270.

holochlorus, 220, 226, 227, 230, 234, 236, 240,

242, 244, 245, 250, 253, 254, 259, 262,

266,

jendaya, 220, 226, 227, 230, 231, 234, 238,

239, 245, 248, 253, 254, 255, 259, 261, 262
266, 272, 276.

Coracopsis, 221, 226, 227, 234, 236, 241, 242, 243
244, 245, 249, 253, 254, 258, 262, 264, 268.
vasa, 220, 227, 236, 274, 276.

Corvus, 261.

Cyanolyseus, 226, 227

261, 262, 263.

patagonicus, 219, 230, 234, 239, 268.

Cyanorhamphus, 226, 227, 234, 243, 245, 249, 251,

254, 255, 261, 262, 263, 264, 266.

auriceps, 224, 231, 242.

Cyclasterope brevis, 183, 208.

fascigera, 181, 202. -

similis, 183, 206.

Cygnus, 261.

Cypretta sarsi, 195, 210.

Cypridina foveolata, 184, 204.

granulosa, 184, 202.

insolita, 184, 204.

Cypridinodes, gen. nov., 187.

favus, 187, 204.

Cypridopsis aculeata, 193.

—— marmorata, 198, 206.

minna, 195.

, 284, 239, 245, 249, 252, 253,

Cyprinotus dentato-marginatus, 196, 206,
fragilis, 196, 206, 210.

prasina, 196.

Cypris flewihs, 192, 206.

letevirens, 193, 206.

Cypris virens, 192, 206.
Cythere lutea, 198.
vubida, 198.
sicula, 198, 210.
Dacelo gigas, 391.

Degen, E. Ecdysis, as Morphological Evidence of
the Original Tetradactyle Feathering of the
Bird’s Fore-limb, based
Perennial Moult in Gymnorhina tibicen, 347-

especially on the

412.

Deroptyus, 226, 227, 234, 244, 245, 246, 263, 264,
266.
accipittinus, 220, 229, 240, 242.

Dinoceras, 292.

Dipsosaurus, 23.

Dolichonyx oryzivorus, 352, 410.

Dolichosoma longissimum, 323.

Dromeus, 261.

Ecdysis, as Morphological Evidence of the Original
Tetradactyle Feathering of the Bird’s Fore-limb,
347-412.

Eclectus, 226, 227, 231, 233, 245, 249, 250, 252,

253, 254, 255, 258, 259, 261, 262, 263, 268.

pectoralis, 220, 230, 231, 233, 235, 278.

Ectodus descampsi, 141.

longianalis, 141, 154, 176.

melanogenys, 141.

Emydura, 62.

Eos, 222, 226, 227, 243, 247, 249, 252, 253, 254,

255, 257, 258, 259, 261, 262, 263.

reticulata, 213.

riciniata, 226, 232, 234, 242, 245, 266, 272,

278.

Equus johnstoni, 281, 282, 303.

Eretmodus cyanostictus, 141.

Eubalena antipodarum, 89.
Euchonchecia chierchie, 190, 208.
Eupathistoma natans, 185, 186.
Fishes, on the Breeding-habits of some West- Meccan
115-136.

of Lakes Tanganyika and Kiyu, Report on
Mr. J. E. 8. Moore’s Collections of, 137-178.
Galeopithecus, 289.

Galesaurus, 3.

Gallinula chloropus, 404.

Gecko verticillatus, 71.

Gephyrochromis moorti, 141, 156, 178.
302

424 INDEX.

Giraffa, 285, 287, 288, 289, 290, 291, 292, 293,
294, 295, 296, 297, 300, 303, 305, 307.

Girafide, on the new Genus Okapia of the Family,
9779-314.

Globicephalus, 90.

Glossopsittacus concinnus, 407.

Glyptodon, 292, 296.

Gnathonemus stanleyanus, 137.

Grammatotria lemairv, 141.

Gymnarchus niloticus, Nesting-habits of, 115, 126,
131, 182, 136.

Gymnorhina leuconota, 403.

tibicen, on the Moult in, 347-412.

Haplochilus tanganicanus, 140.

Haplodactylus, 18.

Hatteria punctata, 71, 72, 73, 74.

(Sphenodon) punctatus, 74.

Helladotherium, 282, 285, 294, 300, 303,

Heptanchus, 329.

Heterodesmus, 188.

Heterotis niloticus, Nesting-habits of, 115, 128, 132,
136

Homeosaurus, 72.

Howes, G. B., and Swinnerton, H. H. On the
Development of the Skeleton of the Tuatara,
Sphenodon punctatus; with Remarks on the
Ege, on the Hatching,.and on the Hatched
Young, 1-86.

Hydrocyon lineatus, 137, 140.

Hyloplesion, 52.

Hyperodapedon, 4, 36.

Hyperopisus bebe, Nesting-habits of, 115, 130, 131,
132, 136.

Ichthyology of Lake Tanganyika, Third Gontribas
tion to the, 137-178.

Ichthyophis, 44, 50, 332.

glutinosa, 46.

Iguana, 57.

Julidochromis ornatus, 141.

Kadaliosaurus, 36.

Kivu (Lake), on Mr. J. E.S
Fishes from, 137-178.

Kobus ellipsiprymnus, 287.

Lacerta, 41, 51, 57, 58.

agilis, 25.

S. Moore’s Collection of

ocellata, 25.

viridis, 7

Lamprologus brevis, 140.

compressiceps, 140.

elongatus, 140.
—— fasciatus, 140.
—— furcifer, 140, 150.
hecqui, 140.

—— lemairii, 140, 150.
modestus, 140.
moorti, 140.
tetrnacanthus, 140.
tretocephalus, 140.

Lanius procerus, 396.

undulatus, 396.

Lankester, E.R. On Okapia, a new Genus of Giraf-
Jide from Central Africa, 279-314.

Lates microlepis, 140, 149.

Lathamus, 270.

Lepidosiren, 121, 122, 123, 124, 125, 126.

Lepidosteus, 321, 324, 327, 332, 334, 335, 336,
337.

Lomvia troile, 406, 407.

Lophophorus, 261.

Loriculus, 224, 226, 227, 245, 249, 253

259, 261, 262, 263, 264 4, 266.

galgulus, 224, 230, 234, 240, 274, 278.

Lorius, 226, 242, 243, 246, 247, 249, 250, 254,

255, 257, 258, 261, 263, 264. <

domicella, 213, 225, 227, 232, 234, 245, 247,

251, 254, 258, 259, 262, 266, 274, 278.

flavo-palhiatus, 213, 224, 225, 226, 227, 232,

234, 245, 252, 254, 256, 258, 259, 262, 266,

278.

Malopterurus electricus, 140, 149.

Mastacembelus ellipsifer, 141.

frenatus, 141, 158, 178.

moori, 141.

ophidium, 141.

— teniatus, 141, 160, 178.

tanganice, 141.

Megapiera, 96, 98, 99, 105.

Melopsittacus, 405.

Microconchecia clausii, 199.

Microglossus, 226, 227, 235, 245, 249, 253,.258,

262, 263, 264, 268.

aterrimus, 213, 219, 229, 233.

Moore, J. E. 8., on the Fishes collected in Lakes
Tanganyika and Kiyu by, 137-178.

INDEX. 4

Mormyrus longirostris, 137.

Mosasaurus, 14.

Moult of Gymnorhina tibicen, 347, 412.

Mudge, G. P. On the Myology of the Tongue of
Parrots, with a Classification of the Order, based
upon the Structure of the Tongue, 211-278.

Muscicapa atricapilla, 411.

collaris, 411.

parva, 411,

Mylodon, 296.

Myology of the Tongue of Parrots, Mudge on the:
211-278.

Nasiterna, 221, 226, 237, 243, 245, 249, 251, 253,

254, 259, 261, 262, 263, 264.

pusio, 218, 230, 233, 268, 278.

Nectarinia, 261.

_Necturus, 50,

Neobalena marginata, Osteology of, 87-114.

Nestor, 226, 227, 245, 247, 249, 250, 258, 254,

255, 257, 259, 262, 263, 270.

notabilis, 224, 232, 233, 235, 262, 266, 274,

278.

Nymphicus, 226, 227, 234, 243, 245, 255, 266.

uvoeensis, 224, 227, 241.

Okapia, 279-314.

johnstoni, 288, 302, 303, 310.

Opisthocomus, 261.

Osteology of the Pigmy Whale, 87-114.

Ostracoda, on new or imperfectly-known, 179-210.

Otis, 261.

Paleohatteria, 22, 26, 30, 36, 5

Paleornis, 220, 226, 227, 231
253, 254, 255, 259, 261, 262, 263.

—— torquata, 220, 231, 240, 250, 268, 272, 276.

Paleotragus, 288, 296, 303.

Palamedea, 261.

cornuta, 270.

Paraconchacia gracilis, 199.

inermis, 199.

oblonga, 199.

spinifera, 199.

Paratilapia aurita, 141, 150, 176.
bloyett, 138, 141, 151.
calliura, 141, 151, 176.
dewindti, 141.

Sureifer, 141.

leptosoma, 141, 152.

bo
a

Paratilapia macrocephala, 137.

macrops, 141,
moeruensis, 137.

nigripinnis, 141, 152, 176.

—— pfefferi, 141.

stenosoma, 141, 151, 172.

ventralis, 141.

—-— vittata, 141, 150, 174.

Pariasaurus, 3, 69.

Parrots, Mudge on the Myology of the Tongue of,
211-278.

Pelecanus, 261.

Pelmatochromis lateralis, 154,

polylepis, 141, 153.

Peloneustes, 2.

Perea, 156.

Perissodus microlepis, 141.

Perissoglossa, 212. -

Petrochromis polyodon, 141, 158.

tanganice, 141, 158.

Pezoporus, 221, 225, 226, 227, 234, 245, 249, 251,
253, 254, 255, 257, 258, 259, 261, 262, 263,
264, 266.

formosus, 222, 223, 231, 242, 272, 278.
Philomedes debilis, 186, 202.

sculpta, 182.

sordida, 186, 208.

Phrynocephalus, 30.

Phyllodactylus, 18.

Physalus antarcticus, 88.

latirostris, 99.

Pionopsittacus, 226, 227, 234, 245, 249, 253, 255,
261, 262, 264, 266.

pileatus, 230, 234, 240, 278.

Platycercus, 221, 222, 226, 227, 234, 242, 243, 245
249, 251, 254,-255, 259, 261, 262, 263, 266.
eximius, 221, 231, 241, 272, 278, 351, 360,
382, 407.

Platydactylus, 51.

Plecodus paradoawus, 141.

Plectrophenax nivalis, 390, 410.

Plesiosaurus dolichodirus, 2.

Pleurodira, 62. ;

Peocephalus, 231, 237, 242, 244, 249, 251, 254,
255, 259, 262, 263, 264.

robustus, 222, 226, 227, 231, 233, 241, 245,
249, 254, 261, 263, 266.

3

42.6 INDEX.

Peocephalus riippelli, 221, 222, 226, 227, 231, 233,
237, 241, 245, 254, 261, 262, 266, 272.

Polypterus, Results of the Search for Hggs of, 115,
116.

——, on the Structure of the Larval, 315-346.

—— bichin, 142.

congicus, 140, 142.

—— lapradii, 317.

, Description of the Larva of, 115-136.

—— senegalus, 116, 117, 119, 317.

Prioniiurus, 226, 227, 234, 245, 249, 251, 254,

256, 259, 260, 261, 262, 263, 264, 266.

sp., 222, 231, 242.

Pristiurus, 50.

Procellaria, 261.

Procolophon, 5.

Proterosaurus, 36.

Protopterus, the Habits and Life-history of, 115,
UE),

— ethiopicus, 140.

annectens, an Account of the External Features

in Development of, 115-136.

Psephotus, 226, 227, 234, 249, 251, 254, 255, 261,

262, 264, 266.

awanthorrhous, 220, 227, 242.

Pseudopus, 14.

Psittacula, 226, 227, 234, 245, 249, 253, 254, 259,

261, 262, 263, 266.

passerina, 224, 231, 242, 278.

Psittacus, 212, 218, 220, 222, 226, 227, 234, 236,
237, 243, 244, 245, 249, 251, 253, 254, 258,

259, 261, 262, 263, 264, 268.

erithacus, 220, 230, 272, 274, 276.

leucocephalus, 212, 213.

macao, 211.

Psittinus, 222, 225, 226, 227, 230, 245, 249, 250,

252, 254, 261, 262, 263, 266.

incertus, 221, 222, 228, 240, 276.

Ptistes, 226, 227, 234, 237, 240, 241, 245, 249,

251, 253, 254, 258, 259, 261, 262, 263, 264,

266.

- erythropterus, 217, 223, 231, 240, 272, 276.

Pyrocypris americana, 185, 202.

chierchie, 185.

revilli, 186.

Pyrrhulopsis, 226, 227, 232, 245, 249, 250, 255,
258, 262, 263.

Pyrrhulopsis personata, 225, 230, 234, 242, 266.
splendens, 224, 225, 230, 234, 242, 266.
Pyrrhura, 224, 226, 227, 239, 245, 249, 252, 253,
254, 262, 263, 266.

leucotis, 224, 228, 234, 239, 274, 278.

Rana, 50.

Ranodon, 42.

Rhachianectes, 106.

Rhea, 261.

Ehynchocephalus, 73.

Tthynchops, 2.

Rhynchosaurus, 4.

Rhynchotus, 261.

Rhytidoceros, 261.

Samotheriwm, 288, 289, 293, 296, 303, 305.

Sapheosaurus, 54,

Sarcodaces odoé, Nesting-habits of, 115, 130, 132,
136.

Sarsiella ornithoides, 189, 206.

Sauranodon, 3, 54.

Sauromalus, 23.

Schilbe mystus, 137.

Sclerocephalus, 69, 71.

Simochromis diagramma, 141, 156.

Sivatherium, 288, 289, 292, 293, 296.

Spathodus erythrodon, 141.

Spheniscus, 261.

Sphenodon diversum, 72.

giintheri, 72, 73.

— punctatus, on the Development of the Skeleton

of ; with Remarks on the Egg, on the Hatching,

and on the Hatched Young, 1-86.

(Hatteria) punctatus, 74.

Stellio, 30.

Stereosternum, 36.

Stringops, 217, 218, 225, 226, 227, 230, 236, 243,

245, 248, 253, 254, 255, 256, 258, 259, 261,

262, 263, 268.

habroptilus, 216, 228, 233, 272, 274, 276.

Stria, 365.

Struthio, 261.

Sus, 289.

Swinnerton, H. H., and Howes, G. B. On the
Development of the Skeleton of the Tuatara,
Sphenodon punctatus; with Remarks on the
Egg, on the Hatching, and on the Hatched
Young, 1-86.

INDEX, 427

Sylvania mitrata, 360.

Synodontis granulosus, 140, 149, 170.
multipunctatus, 140, 149.
ornatipinnis, 137.

zambesensis, 137.

Syrnium, 361, 362.

Tanganyika (Lake), Third Contribution to the Ich-
thyology of.— Report on the Collection of
Fishes made by Mr. J. E. S. Moore in, 137-
178.

Tanygnathus, 226, 227, 284, 245, 249, 253, 255,

259, 261, 262, 263, 266.

milleri, 222, 231, 240.

Lelmatochromis temporalis, 141, 156.

vittatus, 141.

Tetraceros, 292.

Thamnophilus, 396.

Tilapia boops, 141, 158, 176.

burtoni, 138, 141, 157.

dardennii, 141, 157.

grandoculis, 141.

horit, 141.

—— labiata, 141, 157.

microlepis, 141, 158.

natalensis, 137.

nilotica, 188, 141, 157.

—— pleurotenia, 141, 157, 174.

Tilapia polyacanthus, 137.

rubropunctata, 141.

trematocephala, 141, 157, 176.

Tongue, Mudge on the Myology of the Parrots’, 211-
278.

Trematocara marginatum, 141, 155.

unimaculatum, 141, 155, 174.

Triton, 50.

Tropheus annectens, 141.

moorit, 141.

Tuatara, on the Development of the Skeleton of the ;
with Remarks on the Egg, on the Hatching, and
on the Hatched Young, 1-86.

Lupinambis, 15, 57.

Tylosaurus, 14.

dyspelor, 34.

Vanga, 396.

Varanus, 57.

Vini, 226, 227, 243, 249, 254, 255, 257, 259, 261,
262, 263.

australis, 225, 232, 234, 242, 245, 266,
Whale (Pigmy), Osteoiogy of the, 87-114.
Xenochromis hecqui, 141, 159.

Xenotilupia ornatipinnis, 141, 164, 174.
sima, 141, 155.
Zootoca, 41, 53, 56.

END OF VOLUME XVI.

PRINTED BY TAYLOR AND FRANCIS, RED LiON COURT, FLEET STREET,

TAI atee tale
» ‘7Ae

,

TRANSACTIONS OF THE ZOOLOGICAL

(continued).

VOLUME
Part 1.

VOLUME XY. (1898-1901, contaiming 52 Plates)
Parr 1.

VOLUME XVI. (1901-1908, contaming 38 Plates)
Part 1.

9

me

3
4,
5.
6
7
8

2.

oa eB ww

XIV. (1896-1898, containing 47 Plates)

(1896, containing

(1896, containing

. (1897, containing
. (1897, containing 10 Plates)

(1898, containing

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CONTENTS.

IX. Eedysis, as Morphological Evidence of the Original Tetradactyle Feathering of
the Bird’s Fore-limb, based especially on the Perennial Moult i Gymnorhina
tibicen. By Epwarp Decun, 7.2.8. (Plates XXXVI.-XXXVIIL) page 347

List of the Papers contained in Vol. XVI... . . . . . «» » « « « 419
Index of Species, &c. in Vol. XVI. Th ae aE ae ee Seppe ts de 7 L
Titlepage and Contents to Vol. XVI.

THE PUBLICATIONS OF THE ZOOLOGICAL SOCIETY OF LONDON.

‘J'nie scientific publications of the Zoological Society of London are of two kinds—“ Proceedings,”
published in an octavo form, and “Transactions,” in quarto.

According to the present arrangements, the “ Proceedings”’ contain not only notices of all busi-
ness transacted at the scientific meetings, but also all the papers read at such meetings and recom-
mended to be published in the “ Proceedings” by the Committee of Publication. A large number
of coloured plates and engravings are attached to each annual volume of the “ Proceedings,” to
illustrate the new or otherwise remarkable species of animals described in them. Among such
illustrations, figures of the new or rare species acquired in a living state for the Society’s Gardens
are often given.

The “ Proceedings ”’ for each year are issued in four parts, on the first of the months of June,
August, October, and April, the part published in April completing the volume for the last half of
the preceding year. Commencing from January 1901 they form two half-yearly volumes.

The “‘ Transactions”’ contain such of the more important communications made to the scientific
meetings of the Society as, on account of the nature of the plates required to illustrate them, are
better adapted for publication in the quarto form. They are issued at irregular intervals.

ellows and Corresponding Members, upon payment of a Subscription of £1 1s. before the day of
the Anniversary Meeting in each year, are entitled to receive all the Society’s Publications for the
year. They are likewise entitled to purchase the Publications of the Society at 25 per cent. less
than the price charged for them to the Public. A further reduction of 25 per cent. is made upon
purchases of Publications issued prior to 1871, if they exceed the value of five pounds.

Fellows also have the privilege of subscribing to the Annual Volume of the ‘ Zoological Record’
for a sum of £1 (which includes delivery in the United Kingdom only), but this privilege only
holds good if the:subscription is paid before the First of December in each year.

Such of these publications as are in stock may be obtained at the Society’s Office (3 Hanover
Square, W.), at Messrs. Longmans’, the Society’s publishers (Paternoster Row, E.C.), or through
any bookseller. —.

Mav. 1908 P. CHALMERS MITCHELL,
ost ee Secretary.

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