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



specimens collected at Boquete, and hence topotypes of Mr. 

 Bangs's Peromyscus cacabatus, or from the type and 4 topo- 

 types kindly sent me for comparison by Mr. Bangs. Nine 

 adult skulls from Irazu and vicinity (practically topotypes of P. 

 nudipes} do not differ appreciably in measurements or other- 

 wise from the 5 adult skulls of P. cacabatus received from Mr. 

 Bangs, the average difference in occipito-nasal length being 

 only .4 of a millimeter. The external measurements of 10 

 adults from the Irazu series compared with measurements of 

 a similar series from Boquete, recently published by Mr. 

 Bangs (Bull. Mus. Comp. Zool., XXXIX, 1902, p. 30), shows 

 that the total length is practically the same in the two series 

 (varying only about i mm.), but the Irazu specimens show a 

 greater tail length (by about 8 mm.), and a larger hind foot 

 (by about 2 mm.) than the Boquete specimens. This appar- 

 ent difference is doubtless due to different methods of measur- 

 ing, especially as respects the relative length of the tail. 



1 8. Tylomys watsoni Thomas. One specimen, adult male, 

 Boqueron, Oct. 31. 



19. Sigmodon borucae chiriquensis, subsp. nov. 



Type, No. 18789, $ ad., Boqueron, Chiriqui, Oct. 28; J. H. Batty. 



Similar to 5. boruccz, but darker and more heavily colored, the upper 

 parts being deep yellowish brown, varied with black instead of light 

 yellowish brown, and the underparts strongly buffy instead of white; 

 nose and sides of upper lip broadly ochraceous buff instead of pale 

 buff; bullae more pyriform and postpalatal opening much broader. 



Type, total length, 280; head and body, 175; tail vertebrae, 105; 

 hind foot (in dry skin) ,32; ear, 20. An adult female is a little smaller, 

 but has a longer tail (tail vertebrae, 115). 



Represented by 6 specimens, all from Boqueron, collected Oct. 12- 

 27. 



S. b. chiriquensis closely resembles in coloration S. toltecus 

 saturatus Bailey from Chiapas and Vera Cruz, Mexico, but 

 differs from it in cranial characters. It differs from 5. borucos 

 in color and cranial characters, as noted above, boruccz being 

 paler with a tendency to a grayish cast on the head and 

 anterior half of the body in slight contrast with the posterior 

 half, while in chiriquensis the coloration of the upper parts is 



