62 Mr. O. Thomas on 



of the two first molars on their outer edge as a gauge, the 

 species may be arranged as follows : — 



A. First two molars 4*0 ram. and upwards. 



a . 4-4-4-s mm. (Central America.) 1. centralis. 



b. 4'0-41 mm. (Paraguay.) 2. occultus. 



B. First two molars less than 3-9 mm. 



a. Forearm about 46-48 mm. 



a'. Two molars 3'6-37mm. Brain-case swollen. 



(Paraguay.) 3. foster i. 



h '. 3 - 4-35 mm. Brain-case less swollen. 



a 2 . Colour darker and richer. (Brazil.) 4. nasutus. 



b 2 . Colour pale and dull. (N. Argentina.) . . 5. ancilla. 



b. Forearm 43 mm. (Amazonia.) 6. pamana. 



1. Promops centralis, sp. n. 



Size largest of the genus. Colour dark rich blackish 

 brown ; bases of hairs more prominently white than in the 

 next species. 



Forearm of type 54 mm. ; metacarpal of third finger 

 56 mm. 



Skull : greatest length from occiput to base of incisors 

 20*2 ; condyle to front of canine 19*3 ; maxillary tooth-row 

 8*3 ; m 1 and m 2 on outer edge 4*5. 



Hah. N. Yucatan, Central America. 



Type. Adult female. B.M. no. 94. 2. 5. 4. Collected by 

 G. F. Gaumer. Presented by Osbert Salvin, Esq. Three 

 specimens. 



2. Promops occultas, sp. n. 



Slightly smaller than P. centralis, the skull hardly smaller, 

 though there is proportionally more difference in the teeth. 

 Colour rather less rich brown, and with less white at the 

 bases of the hairs. 



Forearm of type 51 mm. ; third metacarpal 54*5. 



Skull: greatest length 20; condyle to. front of canine 

 18*8 ; maxillary toolh-row 7 - 9 ; m 1 and m 2 on outer 

 edge 4 f 0. 



Hob. Paraguay. Type from Sapucay. 



Type. Adult female. B.M. no. 2.4.11.24. Original 

 number 714. Collected Otli March, 1902, by W. Foster. 

 Two skins and two spirit-specimens. 



The great difference between this and the other Paraguayan 

 species, P. fasten', had not been previously noted owing to the 

 fact that, the Museum being well supplied with specimens 

 of P. fosteri, the skulls were left in the spirit-specimens, and 

 the skins were made into duplicates and have only now had 

 their skulls cleaned. 



