20 THE VOYAGE OF H.M.S. CHALLENGER. 



Leptonychotes, 1 Gill. 



Lepionychotes, Gill, Arrangement fam. Mam., 1872. 



On the 9th January 1874, a seal, regarded as a Sea Leopard, and believed to be a 

 female, was shot at Betsy Cove, Kerguelen. The skeleton was preserved and sent home. 

 It is referred to in the Narrative of the Voyage of the Challenger (vol. i. p. 355), and on 

 p. 373 it is stated that the sandy beach of Heard Island was strewn with bones of both 

 the Elephant Seal and the Sea Leopard, those of the former being the more abundant. 



Leptonychotes weddelli (Lesson) (Plate V.). 



Otaria Wedddlii, Lesson, Ferussac's Bull. d. Sci. Nat., vol. vii., 1826, pp. 437, 438. 

 Leptonyx weddelli, Gray, Ann. and Mag. Nat. Hist., vol. x., 1836. 



False Leopard Seal, or Weddell's Seal. 



The comparison of the skull of the animal shot at Betsy Cove with the drawings and 

 descriptions of the crania of the seals figured by Dr. Gray in the Zoology of the Voyage 

 of the "Erebus" and "Terror," 2 has satisfactorily shown that the specimen was not a true 

 Sea Leopard, such as is included under the generic names Stenorhynchus (Ogmorhinus) 

 and Lobodon, but that it was like the specimen of the seal from Santa Cruz, which was 

 named by Dr. Gray after Captain Weddell. Short notes on the characters of the 

 skull of Weddell's Seal have been given by Messrs. Allen and St. George Mivart in their 

 monographs already referred to, but the skeleton generally has not yet been described. 



Skeleton. — The animal was not an adult, for the vertebral plates were not united to 

 their centra, and the epiphyses of the bones of the shafts of the limbs were not ankylosed. 



Skull. — In drawing up the following description I have examined and compared the 

 skull of Weddell's Seal from Betsy Cove with two well-grown crania of Stenorhynchus 

 (Ogmorhinus) leptonyx, one of which was from Wellington Harbour, New Zealand, 3 but 

 the locality from which the other and somewhat older specimen came is unknown. 



In Table III. I have given the comparative measurements of these crania. 



In none of the skulls was either of the basi-cranial synchondroses ossified, though the 

 interval between the bones was scarcely more than would admit the edge of a knife. 



The dental formula of Stenorhynchus leptonyx was — 



. 2-2 1-1 5-5 



in -2^2 c -r=n p- c -5^5' 



and of Weddell's Seal, 



2-2 1-1 6-5 



in. 



2-2 "1-1 P-C '5-5 



1 As the generic name Leptonyx, given to Weddell's Seal by Gray, has also been applied to one of the Mustelida?, 

 to one if not two genera of Birds, and to a genus of Gastropodous Molluscs, I have preferred to adopt the generic name 

 Leptonychotes employed by Gill and Allen. 



2 Vol. i., Mammalia, London, 1814-1875. 



3 This skull was presented to the Anatomical Museum of the University of Edinburgh by Sir James Hector, F.R.S., 



