1 92 Bulletin American Museum of Natural History. [Vol. XXII, 



Osgood, Assistant, Biological Survey, for kindly determining the 

 specimens of Peromyscus, nearly all of which have passed through 

 his hands in connection with his monographic revision of the group, 

 now nearly ready for the press. 



I. MAMMALS FROM SOUTHERN SINALOA. 



The Sinaloa collection was made in the extreme southern part 

 of that State, mostly within a radius of about a dozen miles from 

 Escuinapa (spelled Escuinada on some maps), which point was the 

 collector's headquarters and base of supplies. Most of the specimens 

 are hence labeled simply Escuinapa. His work was thus mainly 

 confined to a narrow coast strip extending from Rosario southward 

 totheTepic boundary, some fifteen miles south of Escuinapa. This 

 low strip of coast country "is covered with lagoons and rivers. It 

 has a heavy growth of mangroves, and is sparsely interspersed with 

 sandy knolls -and flat patches of higher ground covered with other 

 vegetation. East of the lagoons, for the five miles to Escuinapa, 

 and thence to the foothills of the Sierra Madre, is a long flat plain 

 covered mostly with thorny bushes, yuccas, and patches of high grass. 

 On this tract are scattered occasional ranches. Northwest of Escui- 

 napa the country is the same for several hundred miles. The same 

 character of country continues also southeast for seventy miles. . . . 

 East of Escuinapa rise small bushy hills, sparsely covered with 

 chapparal, mesquite, and other thorny bushes and trees. Twenty 

 miles directly east, the altitude is about 3000 feet, at sixty miles 

 5000-6000 feet, and at the boundary of Durango about 8000 feet. . . . 

 At 4000 feet, oaks first appear; at 5000 or 6000 feet there are grassy 

 hills, the valleys between being wooded, principally with large oaks. 

 Still higher, the oaks are mostly replaced by scattered groves of 

 large pines." 1 



During nearly a year (December 19, 1903, to November 9, 1904) 

 spent in this region, Mr. Batty exhaustively explored the immediate 

 vicinity of Escuinapa, from the coast lagoons and small islands 

 (Hacienda Island and Los Cabras Island) on the coast to the dry 

 plains and knolls to the eastward of the adjoining low coast plain, 

 the altitude ranging from sea level to 100 feet. Excursions were 

 made northward to Rosario (the type locality of a number of small 

 mammals collected by Mr. P. O. Simons in 1897), about twenty 



Compiled by Mr. W. De W. Miller from the collector's notes; see this Bulletin, Vol. XXI, 

 pp. 339, 34- 



