732 MR. R. H. BURNE ON THE [June 15, 



My friend and predecessor Dr. P. L. Sclater having called my 

 attention to the want of a good figure of the young Walrus, taken 

 from a living specimen, I was fortunate enough to enlist the interest 

 of Mr. Carton Moore Park, F.Z.S., who made a series of careful 

 studies from the living animal, one of these being reproduced 

 in Plate LXXVI. The figure shows the animal in a characteristic 

 attitude. The general coloration is a dull rusty black approaching 

 to mahogany over the body generally, and with a strongly marked 

 bluish tint on the naked parts of the face and flippers. The hair 

 of the fur was nearly bluish black when dry. The eyes were 

 brown and very soft and intelligent. The whiskers were trans- 

 lucent, and varied in colour from white or yellow to light-blue 

 according to the incidence of the light falling on them. 



EXPLANATION OF PLATE LXXVI. 



Young: Walrus, Odohmnus rosmarus, drawn from a living example hj Mr. Carton 

 Moore Park, P.Z.S. 



7. Notes on the Viscera of a Walrus [Odohamus rosmarus) . 

 By R. H. BuRNE, M.A., F.Z.S. 



[Received May 24, 1909.] 



(Text-figures 231-234.) 



Through the kindness of Mr. Beddard, some of the viscera of 

 the young female Walrus, lately living in the KSociety's Gardens, 

 were sent to the College of Surgeons for use in the Museum. 

 Several preparations were made from them by the Prosector 

 (William Pearson), and although the anatomy of the Walrus 

 is fairly well known, particularly from the researches of Dr. Mvirie 

 published in the Transactions of this Society for 1872, some few 

 points worthy of record ai-e shown by these new specimens. 



The diaphragmatic sphincter of the vena cava inferior. 



Among the viscera supplied to the Museum were the heart and 

 lungs, and in connection with them the upper part of the vena 

 cava inferior and a minute fragment of the diaphragm. In making 

 this preparation the Prosector observed that the lower 3 cm. of 

 the thoracic segment of the vena cava inferior was surrounded 

 by a sheath of circularly disposed striated muscle directly con- 

 tinuous with the muscles of the diaphragm (text-fig. 231). The 

 sheath is from 1-2 mm. thick and terminates towards the 

 heart in a sharp, well-defined edge. For some distance from 

 this edge it could easily be freed from the underlying wall of 

 the cava, but was more firmly adherent to it near the diaphragm. 

 A similar muscle has been described in Phoca vitidina and 

 Phoccena communis *, and apparently forms part of a mechanism 

 for controlling the blood-stream in aquatic mammals. 



* Weber, Arch. f. Anat. (Miiller) 1840, p. 236. 



