}rA3rMALS COLLECTED LN WESTERN BORNEO— TA'ON. 561 



[about 90];'^ mastoid breadth, 51.4, 53 [about 55]; zygomatic breadth, 

 58, 58. 9[—]; interorbital constriction, 11.4, 13.7 [— ]; upper tooth 

 row to front of canine, 30.5, 30.7 [32.4]; lower tooth row to front of 

 canine, 38, 38 [42.4]. 



Mr. Gerrit S. Miller, jr., writes that the type of Lutra lovii in the 

 British Museum is "a young hairy-nose with milk canine and next 

 to last premolar in place. Skull broken away beliind." It will be 

 seen from the above measurements that Doctor Abbott's two small 

 otters have much longer tails than has the type of L. lovii , and slightly 

 smaller skulls; and it is not at all unlikely that they represent a 

 different race. As the ty}:)e of L. lovii is young and of the opposite 

 sex from Doctor Abbott's two specimens, it does not seem advisable 

 for the present to name the Bornean form. 



HELARCTOS EURYSPILUS Horsfield. 

 1826. Hdarctoa nmjspiliis Horskield, Zocil. Jouni., II, pp. 221-234, pi. vii. 



A single skull, Cat. No. 142344, U.S.N.M., without lower jaw, 

 from the Landak River, may be referred to Ilelarctos euryspilus, 

 which most authors have regarded as a synonym of //. malayanus, 

 and not without reason, for Horsefield's description of Ilelarctos 

 euryspilus was based on a living example in London, and no char- 

 acters are given to differentiate the two forms. In 1903 Doctor 

 Abbott collected a full-grown male of the Sumatran Helarctos malay- 

 anus along the Kateman River, eastern Sumatra. A compariscm 

 of its skull with the Bornean skull shows well-marked differences 

 between the two insular forms. It should be noted, however, that 

 the tyj^e of H. malayanus came from Bencoolen, some little distance 

 from the Kateman River, and that no locaHty in Borneo is men- 

 tioned for H. euryspilus, so that the following comparison may not 

 be made between t}^ical examples of the two species. Both skuUs 

 are fully adult and of nearly equal age, although the Sumatra one 

 is the older. The sex of the Bornean skull is unknown, but judging 

 from the large size of the canine and other teeth it is without ques- 

 tion not different in sex from the Sumatran skull. 



In addition to the difference in size shown in the following table 

 may be mentioned the greater relative size of the maxillary teeth in 

 the Bornean bear, which are actually as large as in the Sumatran 

 species; the relatively wider palate and its greater posterior exten- 

 sion behind the toothrow in Helarctos malayanus, relatively larger 

 bullas in H. euryspilus, and the very large expansion of that portion 

 of the mastoid applied to the posterior aspect of the auditory canal 

 in the Sumatran species. 



« Measurements in parentheses are those given in the original account of Lrdra 

 lovii (Proc. Zool. Soc. London, 1876, p. 736), and those in brackets measurements of 

 the type skull of Lutra lovii made by Mr. Gerrit S. Miller, jr. 



