422 Bulletin American Museum of Natural History. [Vol. XX, 



Through the kindness of Mr. Witmer Stone, I have been 

 able to compare two of the Cope series of specimens of 

 Cabassous hispidus, now in the Museum of the Philadelphia 

 Academy of Natural Sciences, and also an additional skull in 

 this Museum, from Chapada, Matto Grosso, Brazil, with the 

 present series. The Philadelphia Academy specimens are 

 the specimens used by Mr. Gerrit S. Miller, Jr., in the prepara- 

 tion of his paper entitled ' Notes on the Naked-tailed Arma- 

 dillos' (Proc. Biol. Soc. Wash., XIII, pp. 1-8, figs, i, 2, Jan. 

 31, 1899). A critical comparison of this material leads me 

 to accept Mr. Miller's conclusions as against those of Mr. 

 Bangs- namely, that the Santa Marta form is not only 

 specifically but subgenerically separable from C. hispidus. 

 Externally the Santa Marta form closely agrees with the 

 Central American C. centralis (Miller) , but differs greatly in 

 the form of the skull. The differences in the form and num- 

 ber of plates in the head shield, the size and form of the ears, 

 the absence or presence of minute bony plates on the posterior 

 surface of the ears, are among the obvious distinctions between 

 the C. hispidus and the Ziphila groups, as already made clear 

 by Mr. Miller. The comparatively naked ventral surface and 

 the almost entire absence of bristles at the posterior edges of 

 the plates of the carapace (except on the lower lateral rows) 

 is another feature of contrast between C. hispidus and the 

 Ziphila group. 



It is not, however, so clear that the Santa Marta animal 

 should take the name lugubris, the type locality of which is 

 "St. Catherines, Brazils." In the absence of specimens of 

 true C. lugubris, however, for comparison, this name is here 

 provisionally accepted, although the presumption is, on 

 geographical grounds, that the Santa Marta animal is different 

 from true lugubris from southern Brazil. 



The normal dental formula in the Ziphila group appears to 

 be | - f = If ; but in two specimens out of three in lugubris 

 there is an extra tooth in the right upper toothrow, as follows : 



No. 14862, dental formula, left side, f ; right side, J 8 -- 



" 14863, " " " " |; " " y. 



" 23441, " " " f; " " f 



