1893.] UB. f. J. FOESriH JIAJOU 0>' illOCENB SQUIBRELS. 191 



Sc, si)ennoi)liilinus is represented by a fragineut of the left 

 maxilla ( Plate X. fig. 4), carrying the posterior premolar aud the 

 two anterior molars, and by several mandibular rami (Plate X. 

 figs. 6-9). A minute alveolus for p.^ is visible in front of the 

 posterior upper premolar. The inferior molars show the cup- or 

 basin-shaped conformatiou, the cusps being arranged laterally. 



Deperet is of opinion that the molars of 8c. si)ermox)ldliiim 

 dift'er from Sc vvlijaris only in small particulars. I find more 

 resemblance to some Oriental members of the subgenus Scinrus ; 

 the antero-internal cusp of the lower molars being extremely 

 elevated, whilst the postero-interual cusp is almost suppressed 

 (Plate X. fig. 9). We meet with exactly the same pattern in the 

 Oriental Sv. atrodorsaUs, Gr., Sc. roaeabenji, Jent., Sc. canice^is, Gr., 

 Sc. brookci, Thos., and others. The third lower molar is more 

 elongate than in Sc. vuhjaris; this, too, is a character of the 

 Oriental group of Squirrels mentioned. Besides, both upper and 

 lower incisors are vertically sti-iated by ridges (Plate X. fig. 5). 

 Amongst recent Sciurince, oulv liJdthrusciurns, whose molars, how- 

 e\er, are very different from those of the fossil, presents this 

 character. It occurs also on lo«er incisors of some species of 

 Sc'mroidcs from Cailux, in the British 3Iuseum. As the same 

 striation of incisors is found in the Tillodont Calamodon of the 

 Lower American ' and Swiss - Eocene, it may prove to be an 

 inherited character. 



Length of m.„ m,, p, sup., 6 millim. ; length of m^, m.^, m^ p. 

 inf., 7'5 millim. 



Xerus (ji-ivemi-s, n. sp. (Plate X. figs. 2, 3). — A left mandibular 

 ramus, shoeing the three molars and the alveolus of the pre- 

 molar. Length of the three molars 6 millim. Incisor without 

 vertical ridges. The molars present a more advanced stage of 

 lophodoutism than those of Sc. xpcrinojiliiliaus, not only the 

 anterior cusps uniting transversely, but the postero-external and 

 postero-internal cusp — the latter more fully developed than in 

 Sc. spermopliilinus — showing the same tendency. So that we 

 have three, instead of two, trans\erse valleys, the median and 

 posterior valley being incompletely divided. I could not better 

 characterize the molars of this fossil than by calling them a 

 minute and somewhat less semi-hypsodont form of X. herdmorci, 

 Bly., from Afartabau, Tenasserim, Cambodja, and Cochiu-Chiua. 



SciuroiJtenis alhaneasis, n. sp. — The thii*d fossil, a left ramus of 

 the lower jaw (Plate X. fig. 1, Plate XT. figs. 3-5), is strikingly 

 similar in the character of the molars aud the ramus to some of 

 the larger species of Sc'mroptei-us, and especially to Pteromys Upliro- 

 inehs, Giinth.' (Plate XL figs. 1, 2), aud Pter. pJiceomelas, Giiuth., 



' E. D. Cope, •' The Vertebrata of the Tertiary Formations of the West," 

 Book I. 1883 (Eep. Un. States Geol. Surv. of the Territ. vol. iii., Washington, 

 1884) pp. 188-192, pi. xsiv. c. fig. 1 b. 



^ L. Eiitimeyer, " Die Eocane Saugethierwelt von Egerkingen " (Ziirich, 1891), 

 pi. viii. figs. 25-27, p. 126. 



3 Proc. Zool. Soc. Loud. 1873, p. 413, 1880, p. 53. 



