384 DR. ST. G. MIVART ON THE ARCTOIDEA. [Apr. 21, 



the lower marfrin of the nasal pad. The ears are small, rouiirled, 

 and simy)le. The palmar and plantar surfaces may be naked or 

 more or less hairy, according to the species. 



The tail mav hare (as in the exceptional form L. senclbcic/iii^) a 

 prominent ridge along either side of the tail, and the feet may 

 approximate in form to those of E?ihi/drn. 



There are 14 or 15 dorsal, 6 or .5 lumbar, 3 sacral, and from 20 

 to 26 caudal vertebrae. Both the humerus and radius are at their 

 minimum of relative length in the whole of the Carnivora, as also is 

 the relative breadth of the skull behind the orbits. 



The skull is so long that, though the palate is broad, its length 

 compared with its breadth is greater than in any other Arctoid ; 

 and the excess of the length of the pelvic limb over the pectoral is 

 onlv exceeded by that of Enhydra amongst the whole of the Car- 

 nivora. 



The hyperapophyses on the cervical vertebrae are longer than in 

 any form yet noticed. The are twelve quasi chevron bones to the 

 tail. Each consists of a pair of diverging hypapophyses, which tend, 

 irregularly, to send out mesiad processes below. Each pair depends 

 from the preaxial end of its centrum, beginning at the fourth caudal 

 vertebra. 



Tiie scapula develops a very strong metacromion process, while 

 the acromion is very slender. The preaxial margin of the scapula 

 is exceedingly convex. The humerus may or may not have a supra- 

 condyloid canal. The supinator ridge is very strongly marked. 

 The ulna develops a distinct process from the middle of its shaft, 

 which process abuts against the radius. The ultimate phalanges of 

 the manus are exceedingly short. The femur has a very strong 

 external trochanteric ridge extending down its .shaft. The ultimate 

 phalanges of the pes are of about the same length as those of the 

 manus. 



To the cranial characters given by Prof. Flower^ maj' be added 

 the following :— The skull is much flattened superiorly. The 

 ascending process of the premaxilla does not, so far as I have seen, 

 reach the frontal. The maxilla develops a rudimentary preorbital 

 process^. Venous channels traverse the exoccipital, and open on 

 the inner side of either occipital condyle^. The meatus auditorius 

 externus is relatively small. The foramen condyloideum is con- 

 spicuous. The mastoid process is concave beneath, and does not 

 descend below the meatus auditorius externus. No ridge connects 

 it with the paroccipital process. The palate is not greatly prolonged 

 behind the last molars. The pterygoids descend below the level of 

 the palate. The internasal septum does not extend back to the 

 liinder margin of the palate. The zygomata, though slender, are 

 rather strongly arched outwards. There are both malar and frontal 



^ This is the tvpe of Grav's eenus Pteronnra. See P. Z. S. 1865, p. 131 , 

 1868, p. 66, and VViegmaiin's Arcbiv, iv. p. 392 (1839). 

 2 SeeP. Z. S. 1869, p. 11. 



^ A rudiment of that which is found amongst the Pinnipedia. 

 * Another approximation to the characters of the Pinnipedia. 



