296 DR. KXUD ANDERSEN ON BATS. [Apr. 7, 



Range. — The two specimens examined are the only known. 



Remark. — A. rosenbergi cannot be discriminated, with certaintj^, 

 by any external character from other species of Artibeios of 

 similar size, f. i. ^. tcatsoni, cinereus [ciue^-eus), toltecus. But it 

 is unique in the strong reduction of m". 



Artibeus toltecus Saussure. 



Diagnosis. — Molars |. Cusp 7 of m' large. Bony palate not 

 shortened. Forearm 37'5-43"5 mm. 



A. toltecus and cinere^is. — A. toltecus cannot be discriminated 

 with certainty by any external character from A. cinereus. The 

 interfemoral in A. toltecus is probably, at least on avei'age, 

 mai-kedly shorter, but of one of the races, A. t. ravus, only skins 

 have been available for examination. The skull of A. toltecus is 

 almost precisely, in shape as in dimensions, like that of A. cinereus, 

 the only difference being a proportionately greater maxillary 

 width in A. toltecus. The length of the tooth-rows is practically 

 the same in both species. 



Nothwithstanding this close similarity, A. toltecus and cinereus 

 are not only distinct species, but evidently representatives of two 

 distinct sections of the genus. In^i. glaucus, watsoni, and cinereus 

 cusp 7 of \v} is proportionally small (text-fig. 56 b) ; in ^. toltecus 

 and aztecus (as well as in ^. quadrivittattcs, turpis, and nanus) this 

 cusp is largely developed, being equal to about -_^ to ^ (in glaucus, 



Text-fiij. 56. 



A 



A. Artiheus toltecus ravus, $ ad. Corondelet, N.W. Ecuadoi-. B.M. 1.6.5.3. 



Right upper tooth-row (cusp 7 of m' large). X x- 



B. Artibeus cinereus cinereus, $ ad. Para. B.M. 1.7.19.3. 



Right upper tooth-row (cusp 7 of mi small) . X f- 



watsoni, and ciiiereus to about -^ to \) of the whole tooth (text- 

 fig. 56 a). Also cusp 7 of m" is in toltecus and allied species larger 

 and more distinctly projecting. — The larger cusp 7 of m^ (and m") 

 increases, of course, the breadth of this tooth ; there cannot be 

 much doubt that the proportionally slightly larger maxillary 

 width of the skull of toltecus (and aztecus) mentioned above is 

 a direct consequence of the slightly increased breadth of the 

 molars. 



