Stenodermatous Bat from Trinidad, 169 



Head and body (c.) 73 millim. ; ear, above crown, 9 ; fore- 

 arm 50 ( = 1-96 inch) ; tibia 19. 



Skull : basal length (c.) 20 millim. ; greatest breadth 16*8 ; 

 interorbital, breadth 6*2 ; palate, length 12*6, breadth outside 

 !^ 11-4, inside 'iLi 6-2. 



Teeth: uppercanines, verticallength 3"6, greatest horizontal 

 diameter 2*0, distance from tip of one to tip of the other 4*1 ; 

 front of canine to back of "— 9*8 ; front of !^ to back of 

 «^2 4.7 . transverse breadth of ^— 2'6 ; height of lower canine 

 3*3 ; front of canine to back of 573 10*3 ; front of „n to back 

 of ,-;r3 5-9 ; length of ;;rri 2*2, ,7^ 2*9, ,7^ 0-8. 



No detailed comparison of this new species with its allies 

 is necessary, as its dental formula (I.5, M. 3) at once separates 

 it from every other member of the group except the otherwise 

 very different Artiheiis 'persincillatus and Stenoderma achra- 

 dopliilum. 



In workmg out the relationships of this form, however, 

 several jjoints in connexion with the genera of the group have 

 arisen which seem to be worthy of mention. The number of 

 the molar teeth, a character elsewhere usually of generic 

 importance, here only seems to be of specific value, a fact only 

 recognized after the foundation of almost as many " genera " 

 or " subgenera " as there really exist species. Mr. Dobson, 

 in his invaluable ' Catalogue,' has practically adopted the 

 later views of Prof. Peters on the subject, and has wisely only 

 admitted such genera as are based on other characters than 

 those of the molars ; but some of the species appear to me to 

 be referred to the wrong genera owing to the principle of 

 ignoring the molars not being sufficiently rigidly carried out. 



In comparing the two genera Vampyrops and Chiro- 

 derma Mr. Dobson says of the latter : — " This genus is 

 undoubtedly closely allied to Vamjtyrops. .... The form 

 of the upper and lower first premolars is, however, very 

 different and peculiar ; the second molar in both jaws is larger 

 than any of the other teeth ; and in immature specimens a 

 well-defined cleft extends backward from the nasal opening 

 in the middle between the orbits." 



Now, in my opinion, this last character, that of the nasal 

 cleft, is the only valid distinction between the two genera, and 

 the statement by Prof. Peters that it closes up in old age is 

 simply due to his having wrongly attributed to Ghtroderma 

 an old individual of a species {Phyllostoma pusillum of Wag- 

 ner) really referable to VaiJi^jyrojJS, he at that time thinking 

 that the form and number of the molars was of more import- 

 ance than the presence or absence of the nasal cleft. 



