222 Bulletin American Museum of Natural History. [Vol. XIII , 



dactylinus, and very different in coloration. I. Geoffroy gives 

 (Mag. de Zool., 1840, Mamm., 29) the length of the head and 

 body of the Paris specimen as 350 mm. and the tail as 420 ; Dr. 

 Pelzeln states that Natterer's specimen measured, total length 

 2' 3", length of tail, 15^" ; Dr. Jentink's measurements of the 

 Leyden specimen are, head and body, 328 mm., tail, 406 mm. 

 The corresponding measurements of the type of D. peruanus are, 

 240 mm. and 320 mm. This example is an old female, while the 

 Natterer and Leyden specimens are males, but the difference is 

 apparently far too great to be merely sexual. 



6. Proechimys simonsi Thomas. This recently described 

 species is represented by a single specimen, an adult female, 

 which agrees perfectly with Mr. Thomas's description. 



" I obtained this specimen on a tract of level land on top of the 

 mountain range north of us. The land had been at one time 

 covered with timber, and was an ideal place for mammals, but 

 they proved to be very scarce, as this and No. 34 \jDidelphis 

 pernigra] were all I took during fourteen days with sixteen traps. 

 Its stomach was empty." H. H. K. 



7. Nectomys garleppii Thomas. Four specimens (3 males 

 and i female, all adult), collected Nov. i, 1899, and Jan. 3 and 

 7, and Feb. 20, 1900. 



The collector's measurements from the fresh specimens are as 

 follows : 



16058, $ , Head and body, 214 ; tail, 216 

 16057, $ , " " 241 ; " 242 

 15801, $, " " 240; " 230 



16059, $t " " 2535 " 242 



hind foot, 51. 

 Si- 

 54- 



57- 



The female is wholly destitute of molar teeth in both jaws, 

 and nearly all traces of their insertion have been obliterated by 

 the filling of the former root-cavities by bony deposit. 



" Taken in a pile of slide rock, caused by a landslide. It 

 feeds on a green berry that is common here." H. H. K. 



8. Neacomys spinosus (Thomas). Four specimens 2 

 adult males, i adult female, and i 'young adult' male Juliaca, 

 Nov. 8-13, 1899. In the adults the pelage of the ventral surface 

 is uniform whitish or yellowish white to the base, the tips of the 

 hairs suffused with buff, especially over the pectoral region. In 



