1908.1 



DH. KXUD ANDERSEX ON BATS. 



253 



Diagram showing the percentage of individuals, in the races of Artibeus Jamaicensis, 

 in which the angular emargination between cusps 5 and 7 of m^ (former place 

 of m^) (1) is quite, or almost, as pronounced as in anj^ A. j)lanirostris (upper 

 curve), (2) has almost, or quite, disappeared (lower curve). 



Tragus. — In most individuals tliere are 4 or 5 quite small 

 serrations on the outer margin of the tragus, above the median 

 projection ; the serrations may be sharp, but as a rule they are 

 more or less rounded off, rather often reduced to inconspicuous 

 nodules ; very often the number is reduced to 3 (generally by 

 obliteration of the lower ones), rarely to 2, and still more rarely 

 all serrations are almost obliterated, the margin from the median 

 projection to the tip of the tragus being practically simple. There 

 is every transition between these stages, and they occur in all 

 races. 



Nose-leaves. — According to Dobson A. jamaicensis (A. persjn- 

 cillatus in his 'Catalogue') is "at once distinguished" from 

 A. planirostris by having the front margin of the horseshoe 

 " completely bound down to the muzzle, in some individuals even 

 confluent with its integument," whereas in A. planirostris the 

 margin is " free, separated from the muzzle, straight, unnotched." 

 This character is thoroughly untrustworthy. First, in the same 

 geographical race of A . jamaicensis, often in individuals obtained 

 on the same spot, all transitions can be found, from a horseshoe 

 with the front margin as fi'ee as in any planirostris, to a horse- 

 shoe with the front margin completely continuous with the 

 integument of the muzzle, as shown in the table, p. 254 (based 

 exclusively on specimens preserved in alcohol). Second, in 

 A. planirostris the front margin is, as a rule, more or less fi-ee, 

 but individuals occur in which it is so completely bound down as 

 to be almost confluent with the integument of the muzzle. — The 

 front margin of the horseshoe is often simple, sometimes more or 

 less crenulate ; the crenulations extend not rarely over the whole 

 of the lateral margins, sometimes even over a smaller or greater 



