46 Bulletin American Museum of Natural History. [Vol. XX, 



mens (topotypes), Volcan de Irazu, Feb. 23 and 24, and 

 March 1-6. 



Nine adult males : Total length, 163 (155-174); tail verte- 

 brae, 86 (83-96); hind foot, 19 (18-20). The largest specimen 

 of the series is a female, the collector's measurements being: 

 185, 96, 20. As this species was described from a single skin 

 and skull from Volcan de Irazu, this series of topotypes with 

 flesh measurements helps to complete the description. The 

 type proves to represent the adult condition of the species. 



14. Akodon irazu, sp. nov. 



Type, No. 18128, ? ad., Volcan de Irazu, Feb. 23, 1902; M. A. Car- 

 riker, Jr. 



Smaller, with relatively smaller ears, than either Akodon teguina or 

 A. xerampelinus Bangs, with the upper parts lighter and more yellow- 

 ish brown, and the under parts buffy brown instead of cinnamon 

 brown. A. teguina is even darker and more blackish than- A. t. apricus. 



Total length (type), 125; tail vertebrae, 50; hind foot, 17. The 

 type is an old female with the teeth much worn. Six adult topotypes : 

 Total length, 132 (121-140); tail vertebrae, 51 (50-53); hind foot, 17.3 

 (17-19). 



Skull (type), occipi to-nasal length, 22; basal length of Hensel, 17; 

 zygomatic breadth, 11.5; mastoid breadth, 10; in terorbital breadth, 

 4; length of nasals, 8.3; palatal length, 8; upper toothrow, 4; lower 

 jaw, condyle to base of incisors, n. 



Represented by 8 specimens, collected on the Volcan de Irazu, Feb. 

 23 and 24, and March 36. 



This species is readily distinguished from its nearest allies 

 by its smaller size and paler coloration, as indicated above. 



15. Macrogeomys heterodus (Peters). One specimen, Sa- 

 banilla, near San Jose", July 2. 



Total length, 228; tail vertebrae, 58; hind foot, 37. General colora- 

 tion above, very dark seal brown, with scattered, long, bristly, whitish 

 hairs, most numerous and rather conspicuous on the sides; no white 

 mark on the head; lower parts soiled grayish white, sharply denned 

 against the dark color of the dorsal surface; tail short, naked; feet 

 nearly naked, apparently brownish flesh color in life; claws short and 

 weak, in comparison with those of M. cherriei and allied forms. 



1 6. Lepus (Tapeti) gabbi (Allen). Three specimens, two 



