142 THE FUR SEALS OF THE PRIBILOF ISLANDS. 



There still remain two points worthy of consideration — viz : the cause of death, and whence the 

 entozoa were derived. 



1. Death seems to have resulted from the ulceration of the stomach. It is not clear, though, why 

 the animal should have succumbed so suddenly. Literally speaking, these ulcerations were so 

 extensive that it is curious the animal should have survived so long. The chronic stage of the 

 ulceration alone accounted for this. This instance is one exemplifying pure, chronic gastritis, due, 

 no doubt, to the presence in such numbers of the entozoa. 



2. It has been said by some parties that the entozoa were possibly derived from food given to the 

 walrus after its arrival at the gardens ; but there are many reasons against this being a likely 

 circumstance. In the iirst place, the fact of the entozoa being a new species peculiar to the walrus 

 militates against the above assertion [p., 71]. Again, the ulceration apparently took a longer period 

 to attain the chronic stage extent 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 stomach 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 alae or wings. Body of worm cylindrical, attenuated anteriorly, of 

 a brownish color, except at anterior extremity, which is white ; the posterior extremity is sometimes 

 red. The surface of the body is beautifully and minutely but distinctly striated across; as seen 

 under the microscope (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 apparently all were females. 



The Ascaris simplex of Eudolphi, found in the stomach of the porpoise {Plioeaena communis), very 

 nearly approaches this species in general appearance and size, but differs from it in several respects. 



The Asearis Moolor is less attenuated at the anterior extremity than the A. simplex, and is desti- 

 tute of alae or wings equally at the posterior and at the anterior extremity. The striations on the 

 surface of the body are much finer, and the labia or valves at the mouth are more distinct and larger. 



Length from 2^ to 3 Inches; breadth from 2 to 2i millimeters. 



Habitat: Stomach of a young male walrus (Mws. Brit.). 



Ebexamination of cotypes. — Almost at the moment of going to press we have 

 received through the kindness of Prof. J. Jeffrey Bell, of the British Museum, several 

 of Baird's originals of this worm. All of the specimens are females, and on this 

 account we are unable to definitely place the parasites. They are poorly preserved, 

 but we were able to distinguish a dentigerous ridge on the lips; no intermediate lips 

 were present; the cuticular bands measure 24 /x broad, and are apparently not provided 

 with any finer striation; the oesophagus resembles the oesophagus described by 

 Jagerskiold for A. simplex, oesophageal and intestinal caeca being absent. Further 

 than this we are not willing to make any statements upon the material at hand. 



We refrain from proposing a new name for the homonym A. bicolor Baird, as we 

 doubt the validity of the species. 



b. Dentigerous ridge double. 



