the Lower Amazons. 277 



41. (Ecomys tapajinus, Thos. 



3 . S. 22, 23. Island of Marajo. 



c? . S. 138. Villa Braga, R. Tapajoz. 



$ . 8. 87. Manacapuni, R. Solimoes. 



? . M. 20. Monte Alegre, near Santarem (0. Martins). 



42. Proechimys goeldii, Thos. 



c?. S. 92 ; ? . 90, 91. Acajutuba, Rio Negro. 

 S . 94, 95 ; ? . 93. Manacapuni, R. Solimoes. 

 Five molar laminae are frequently, if not invariably, present 

 among - these specimens. 



43. Cercomys laurentius, Thos. 

 c?. L. 42. Serra do Castello, Ceara (F. Lima). 



44. Echimys armatns, Geoff. 

 <J . 144, 145. Villa Braga, R. Tapajoz. 



45. Lonchothrix emilice, Thos. 

 Supra, p. 114. 



cC. 142. Villa Braga, R. Tapajoz. Type. (B.M. 

 no. 20. 6. 4. 1.) 



This remarkable animal, the prize of the collection, has 

 already been described, but I include it here to make the list 

 complete. 



46. Isothrix bistriata negrensis, subsp. n. 



$ . 89. Acajutuba, Lower Rio Negro, near its mouth. 



Nearly allied to /. b. orinoci, and agreeing with it, as con- 

 trasted with true bistriata, in the presence of marked light 

 postauricular patches and the shortening of the median light 

 crown-patch, which ends opposite the middle of the ears 

 instead of being continued down the nape ; the nape is there- 

 fore blackish all across instead of being divided in the centre. 

 Differing from orinoci by the general colour being strongly 

 suffused with ochraceous, the rump much more ochraceous 

 than the body, the ear-patches buffy instead of whitish, the 

 median crown-patch distinct and buffy instead of being 

 whitish and only vaguely indicated, and by the under surface 

 being strong ochraceous buffy throughout. Tail with the 

 basal two-fifths dull ochraceous instead of a quarter or less. 



•Skull quite as in bistriata and orinoci. 



