. 



the Loioer Amazons. 273 



renders the retention of Miller's genus Dirias advisable. No 

 intermediates occur, and I have seen a small Noctilio, with 

 skull scarcely larger than that of a large Dirias, showing the 

 fully developed Noctilio feet, so that the diminution in the 

 size of the feet does not go pari passu with that of the animal 

 as a whole. 



22. Dirias irex, sp. n. 



c? . 26, 28. Santa Julia, Rio Iriri, Rio Xingd. 



General characters as usual, but size less than in any- 

 known form. Colour of type dull brown above, buffy whitish 

 below; paratype wholly fulvous. 



Dimensions of type : — 



Forearm 53 mm. 



Head and body 65 ; tail 12; ear 22. Third ringer, meta- 

 carpal 47, first phalanx 12 ; lower leg and hind foot (c. u.) 33. 



Skull : greatest length 18 ; condylo-basal length 16 ; 

 condyle to front of canine 15'7 ; zygomatic breadth 13'4 ; 

 breadth of brain-case 11; palatal length S'6 ; front of canine 

 to back of «i 3 7. 



Hab. as above. 



Type. Adult male. B.M. no. 20. 7. 14. 29. Original num- 

 ber 26. Collected loth February, 1914, by Fraulein E. 

 Snethlage. 



This Dirias is markedly smaller than any member of the 

 genus hitherto known, its small size coming out especially in 

 the length of the tooth-row. Dirias minor, Osg.*, supposed 

 by him to be unusually small, appears from the measurements 

 to be of about the size of the majority of our Amazonian 

 specimens, some few only being larger. The two specimens 

 of D. irex agree precisely in the size of the teeth, but the 

 paratype is even smaller than the type in other respects. 



23. Molossus rufus, Geoff. 



c?. 48, 53; ?. 49, 50, 51, 52. Conceicao, Rio Moju, 

 near Para. 



24. Molossus obscurus, Geoff. 



c?.75; $.76,77. Acajutuba, Rio Negro. 

 ? . 131. Villa Braga, R. Tapajoz. 



25. Tadarida macrotis, Gray. 

 cJ . 33 ; ? . 32. Rio Iriri, Rio Xingii. 



* Noctilio minor, Osgood, /. c. 



