t. 1 



Mft 



948 



MONOGRAPHS OF NORTH AMIRICAN KODENTIA. 



Genus COLOTAXIS Copo. 



CololaMt Coi'B, Pul. Bull. no. 15, 1873, 1. . 



-' "Inferior molars 3; crown plicate, with two counected cusps with creacentio see- 

 tion, on the outside, each of which jjives rise to two transverse crests, which are 

 unconnected. Of these crests, the nrteiiur and posterior are marginal and leas devel- 

 oped than the median pair. Intervaln deep, without cement." 



COLOTAXIS CEISTATUS Copo. 



Colotaxu ariatatua Cope, Pall. Bull. no. 1&, 1873, 1. 



"Anterior molar narrower than the others, the cusps partly alternating, the con- 

 necting crests of the exterior wall internally placed, the transverse crest from the pos- 

 terior forming a Y. Anterior cusps well separated. Enamel of all the molars smooth." 

 Anterior face of incisors regularly convex. i<"roni the "Tertiaries of the Plains". 



HYSTRICOMORPHA. 

 IIYSTRICIDvE. 



HY8TRIX VENU8TU8 Leidy. See anfcd, p. 307. 

 ERETHIZON CLOACINUM Cope. See antei, p. 398. 



, , .- ;u..=^ CASTOROIDID.^. 



CA8TOROIDE8 0HIENSI8 Foster. See aii/«>, p. 424. 



Incertw sedi», 

 Gknus AMBLYRHIZA Cope. 

 Amblnrhita Cope, Proc. Acad. Ns(. Sci. Phila. 1868, 313. See qIbo aii<M, p. 421. 

 AMBLYRHIZA INl^DATA Cope. 



AmMj/rkiia inundata CoFE, Proo. Acad. Nat. Sci. Phila. 1868, 313; Proo. Amer. Pbtl. Soc. Phila. 1860, 183, 

 pi. iv, pl. V, flg. 1. 



Genus LOXOMYLU8 Cope. 

 Loxomyliu Cope, Proc. Amer. Phil. 8oo. Phila. 1869, 186. (See also a«(M, p. 421.) 

 LOXOMYLUS L0NGIDEN8 Cope. 



Loxomylua longidena Cope, Proc. Amer. Phil. Soc. Phila. Id69, 187, pl. v, figs. 2, 3. 

 LOXOMYLUS LATIDEN8 Cope. 

 Loxomylua laiidma CoPR, Proo. Amer. Phil. (Soc. Phila. 1870, 608. 



As already noted on a previous page of this work (p. 421), the genera A.itblyrhisa and 

 Loxomylm, together with the species referred to them, were based by Professor Co|ms 

 {I. c.) on detached teeth from the bone breccia of caves, from Angailla Island, West 

 Indies, and are as yet too imperfectly known to render their iifflnitles fully dpparent. 

 In the structure of the teeth, they are allied to the ChiuchiUidw, and also lo Cantoroidi- 

 da, nearly equalling the latter in size, to which group they may prove to be referable. 



