306 DR. KNUD ANDERSEX ON BATS. [Apr. 7, 



Elliot is of no importance as a specific character ; it only means 

 that the supraorbital stripes are fused together in front ; the 

 same is often the case in other species, whenever these stripes are 

 strongly developed. The fur is described as " dusky brown," 

 whereas the type specimen of jjkceotis, according to Miller, does 

 not differ in colour from his series of A. t. ravus, and therefore 

 probably is pale-coloured ; but also this proves nothing about the 

 distinctness of D. jucicnckt ; dichromatism is the rule in the 

 species of Artibeus. 



In brief, neither in the original description of D. jucunda 

 nor in the additional information given me by Professor Elliot, 

 am I able to find a single character by which D. jucunda can 

 be discriminated from A. phceotis. So long as it has not been 

 proved that such characters exist, I must regard the former name 

 as a synonym of the latter. 



Artibeus aztecus K. And. 



1902. Dermanura tolteca (not Saussure) Gerrit S. Miller, Jr., Proc. Acad. N. Sci. 



Philad. p. 404, footnote (12 Sept. 1902). — Morelos, Mexico (specimen 



examined). 

 1906. Artibeus aztecus Kuud Andersen, Ann. & Mag. N". H. (7) xviii. p. 422 



(1 Dec. 1906).— Type locality: Tetela del Volcan, Morelos, Mexico. 



Diagnosis. — Allied to A. toUecus, but in every respect somewhat 

 larger ; metacarpals unusually long ; interfemoral strongly haired. 

 Forearm 45-46*8 mm. 



A. aztecus and toltecus. — A. aztecus has no closer known relative 

 than A. toltecus. As in this latter species cusp 7 of m^ (and m") 

 is largely developed, the maxillary width of the skull propor- 

 tionately large, the number of molars |-. But the skull is in 

 every respect slightly larger and more heavily built, the teeth a 

 little larger. The external dimensions are greater ; in the 

 smallest available specimen of A. aztecus the forearm is 6 mm. 

 longer than in the smallest A . t. toltecus. in the largest specimen 

 3"3 mm. longer than in the largest A. t. toltecus. The metacarpals 

 are unusually lengthened ; in A. toltecus the indices of the third, 

 fourth, and fifth metacarpals are, respectively, 912, 898, and 

 923; in A. aztecus 946, 928, and 954; the first phalanx of 

 the third digit is of the same length as in A. toltecus, but the 

 second phalanx so much lengthened as to be more than \^ the 

 length of the first ; also the second phalanx of the fourth digit is 

 proportionately longer than in A. toltecus (compare wing-indices, 

 on p. 310). AH these modifications of the wing-structure make, 

 of course, a proportionately longer wing; in A. toltecus the 

 indices of the three principal digits are 2037, 1516, and 1419, in 

 A. aztecus 2088, 1565, and 1442." 



The interfemoral is very short (as in A. toltecus) and unusually 

 strongly haired, as is also the upper side of the tibia. 



Colour. — The general colour of the fur, in all the four specimens 

 examined, is quite as in the dark-coloured phase of ^. t. toltecus 

 (above p. 298). Facial stripes very indistinct or completely 



