20 THE GENUS ODOB^ENUS. 



the characters assigned by Fremery as distinctive of several 

 species, and after mentioning at length other features of varia- 

 tion observed by him in a considerable series of skulls, describ- 

 ing several of his specimens in detail, and arriving at the con- 

 clusion that up to that time all the supposed species of Walrus 

 constituted really but a single species, added another, under 

 the appropriate name Trichechus duMus. This with subsequent 

 authors has shared the fate of Fremery's species,* being consid- 

 ered as based merely on individual variation. 



As will be more fully noticed later, two nominal species have 

 been founded on the fossil remains of the Walrus, namely, Tri- 

 chechus mrginianus, DeKay, 1842, and Odobenotherium larte- 

 tianum of Gratiolet, the former based on remains from Accomac 

 County, Virginia, and the latter on remains from near Paris, 

 France. Lankester, in 1865, added still another, based on 

 tusks from the Eed Crag of England, under the name Triclie- 

 chodon Tiuxleyi. 



Dr. Leidy, in 1860, in a paper on fossil remains of the Wal- 

 rus from the eastern coast of the United States, again noticed 

 the differences in the size, length, and curvature of the tusks 

 in specimens from the northwest coast of North America and 

 the common Walrus of the ISTorth Atlantic. He says : "In the 

 course of the preceding investigations [referring to previous 

 portions of his paper], I was led to examine a specimen, in the 

 cabinet of the Academy of Natural Sciences [of Philadelphia], 

 consisting of the stuffed skin of a portion of the head envelop- 

 ing the jaws of a species of Walrus apparently differing from 

 the true Tricliecus rosmarus, of which, as characteristic, I have 

 viewed the figures ,of the skull and skeletons as given by Dau- 

 benton, Cuvier, and De Blainville. The specimen was pre- 

 sented by Sandwith Drinker, Esq., of Canton, China, and was 

 probably derived from the Asiatic shore of the Arctic Ocean. 

 From the worn condition of the upper incisor and molars, it 

 appears to have belonged to an old individual 5 and in the case 

 of the lower jaw, the teeth appear to have been entirely worn 

 out. The tusks are very much larger and are narrower than in 



* Giebel, in 1855, referred to Fremery's and Stannius's species as still need- 

 ing confirmation : " Die von Fremery uach der Beschaffenheit der Ziiline 

 unterschiedenen Arten, Tr. longidensuu&Tr. Cooki; sind liingst als milialtbar 

 erkannt worden und aucli die von Stannius auf Schadeldifferenzen begriin- 

 dete Art, Tr. duUus, entbehrt noch der weitern Bestatigung." SaugetUere, 

 p. 128, footnote. 



