1868.] MR. p. L. SCLATER ON A NEW URSUS. 71 



Again, the ulceration apparently took a longer period to attain the 

 chronic stage extant than the few weeks' residence of the Walrus 

 in the Gardens would account for. Furthermore, the nature of the 

 food given at the Gardens, and the care and regularity with which 

 it was examined, make it unlikely that such swarms of Entozoa were 

 derived from it and developed in so short a period. 



Whether the Entozoa had been derived from the food given on 

 board ship, or in what manner they had originally reached the sto- 

 mach of the Walrus, are questions which I am quite unprepared to 

 answer ; and speculation leaves the matter quite as undecided. 



Dr. Baird has furnished the subjoined description of this Ascaris, 

 which proves to belong to a new species. 



Ascaris bicolor, Baird. 



Head naked ; labia distinct, prominent, rounded, and of moderate 

 size. Both anterior and posterior portions destitute of alse or wings. 

 Body of worm cylindrical, attenuated anteriorl}', of a brownish colour, 

 except at the anterior extremity, which is white ; the posterior ex- 

 tremity is sometimes red. The surface of the body is beautifully 

 and minutely but distinctly striated across ; as seen under the micro- 

 scope (with a power of two-thirds of an inch), the striae on each 

 side terminate in such a manner that the edges of the body appear 

 as if serrated. Caudal extremity thicker than anterior, obtuse, and 

 generally convoluted. 



A great many specimens were found in the stomach ; but appa- 

 rently all were females. 



The Ascaris si7nplex of Rudolphi, found in the stomach of the 

 Porpoise {^Phoccsna communis), very nearly approaches this species in 

 general appearance and size, but differs from it in several respects. 



The Ascaris bicolor is less attenuated at the anterior extremity 

 than the A, simplex, and is destitute of alae or wings equally at the 

 posterior and at the anterior extremity. The striations on the sur- 

 face of the body are much finer, and the labia or valves at the mouth 

 are more distinct and larger. 



Length from 2g to 3 inches ; breadth from 2 to 2\ millimetres. 



Hab. Stomach of a young male Walrus {Mus. Brit.). 



February 13, 1868. 



John Gould, Esq., F.R.S., V.P., in the Chair. 



Mr. P. L. Sclater called attention to a Bear recently added to the 

 Society's Menagerie, which appeared to be distinct from every re- 

 cognized species. In general appearance it somewhat I'esembled the 

 American Black Bear iJJrsus americamis), but differed in its finer 

 fur, larger and less densely clothed ears, ])ale brown muzzle, and 

 white crescent-shaped mark on the chest, which was connected with 



