REPORT ON THE SEALS. (55 



hamular process and pterygoid everted, basi-occipital perforated mesially. Tympanic 

 bulla not ridged and with antero-internal angle truncated. Mandible more slender than 

 in Ogmorhinus. Humerus without a supracondyloid foramen. 



Leptonychotes weddelli (Lesson). Weddell's Seal. Southern Ocean. 



Otaria Weddellii, Less., Ferussac, Bull. Sci. Nat., t. vii. p. 438, 1826.. 

 Leptonyx Weddellii, Gray, Zool. Voy. "Erebus" and "Terror," p. 7, 1844. 

 Leptonychotes iceddelli, Gill, Proc. Essex Inst., vol. v., 1866. 



Post-canines small, with one moderately prominent cusp, though in the 3rd and 4th 

 a rudiment of a posterior cusp is also visible ; the last post- canine distinctly smaller 

 than the rest. Mandible with a faint, incurved tubercle to represent the subcondyloid 

 process and with no angle ; symphysis moderate, the halves of body widely diverging. 



Ommatophoca, Gray. 



Nasals ankylosed together, greatly elongated and reaching to the back of the con- 

 stricted part of the skull ; premaxilla does not reach the nasal ; anterior nares almost in 

 the vertical plane and slightly in front of infraorbital foramina. Orbits very large and 

 the interzygomatic width greater than the cranial ; the lower border of zygoma reaches 

 below the plane of the dentary border of superior maxilla. Malars greatly elongated. 

 Marked protuberance on squamous temporal above and behind root of zygoma. Hard 

 palate slightly emarginate, the apex of the cleft a little behind the posterior border of 

 the maxillary root of the zygoma ; palatal plate of palate bone much smaller than that 

 of superior maxilla. Vomer visible in palatal cleft. Tympanic bulla not greatly 

 swollen, triangular and ridged on inferior surface, prolonged outwards into a strong 

 process which forms the floor of the external meatus, and may extend considerably 

 beyond it as a thick truncated process. Basi-occipital not perforated. Pterygoids 

 everted. Nails rudimentary on front and absent on hind feet. 



Ommatophoca rossi, Gray. Ross's Seal. Antarctic Ocean. 



Ommatophoca Rossii, Gray, Zool. Voy. "Erebus" and "Terror," p. 8, pis. vii., viii., 1844. 



Teeth small ; post-canines three-cusped, the central cusp the longest and recurved. 

 Mandible with a moderate angle and low subcondyloid process ; coronoid short but 

 pointed, sigmoid notch shallow, symphysis moderate, lower border of body slightly 

 incurved. 



The genus Ommatophoca is, so far as we know, represented only by a single species 

 living in the Antarctic seas, two skulls of which are in the Natural History department 



(zool. chall. exp. — fart Lxviu.— 1888.) Yyy 9 



