[ 501 ] 
XVI. Researches upon the Anatomy of the Pinnipedia.—(Part II.) Descriptive Anatomy 
of the Sea-lion (Otaria jubata). By James Muniz, W_D., F.L.S., F.G.S., &c., 
late Prosector to the Society. 
Read December 6th, 1870. 
[Puates LXXV.-LXXXII.] 
; ConTENTs. 
I. The Skeleton and Cranial changes, p. 501. V. Hyolaryngeal and Respiratory Organs, p. 546. 
II. The Nervous System, p. 517. VI. The Digestive System, p. 553. 
III. Sensory Apparatus, p. 534, VII. Urino-generative Organs, p. 567. 
IY. The Vascular System, p. 535. VIII. Description of the Plates, p. 573. 
HAVING in the first part of this Memoir treated of the exterior, of the fleshy body, 
and of the ligaments knitting the osseous frame of the Sea-lion, it follows that I next 
take the skeleton into consideration. H.M. Ducrotay de Blainville, in his magnificent 
‘Atlas of Osteography,’ has figured the skeleton of our Otary, and that of the Walrus 
and the Common Seal; but neither of the two former is placed in the peculiar and 
distinctive attitude these animals assume on land. For this reason I have refigured 
that of the Sea-lion, and added separate illustrations of each of the carpal and tarsal 
bones—a decided want in his great work. ‘The series of crania figured by me I shall 
refer to en passant. 
I. Tur SKELETON AND CRANIAL CHANGES. 
1. The Skull. 
a. General aspects.—Seen in profile, the skull of the Society's young or nearly 
adult ¢ specimen of Otaria jubata exhibits a remarkable flattening of the upper cranial 
surface; the base of the cranium from this view also appears pretty level, and is nearly 
parallel with the horizontal plane of the vertex. From the nasals anteriorly the skull 
slopes considerably ; and posteriorly the occipital truncation is interrupted by the pro- 
jecting condyle. In old age, as subsequently to be shown, the skull of this species does 
not retain the above-mentioned features ; but these evidently hold good in a certain stage 
of growth. 
Three segments or regions are readily mapped off in this side-view. The first or 
naso-maxillary one occupies rather less than a third of the entire length of the cranium, 
and includes the nasal, the intermaxillary, the maxillary bone, and the teeth as far as 
_ the fourth premolar. The anterior or inner margin of the orbit bounds this segment 
VOL. VIII.—PART Ix. June, 1874. 4a 
