1906.] Allen, Mammals from Western Mexico. 193 



miles north of Escuinapa at an altitude of about 500 feet; and to 

 Papachal (altitude 600 feet) and Elota (altitude 800 feet, and about 

 one hundred miles north of Escuinapa) . Very few mammals, however, 

 appear to have been taken at either of these points. In the spring 

 of 1904 (March 15 to May 20) an expedition was made to the foothills 

 of the Sierra Madre, nearly to the Durango-Sinaloa boundary, during 

 which 66 mammals were collected, as follows: Lavanilla, altitude 3000 

 feet, 2 specimens; Los Pieles, altitude 3500 feet, 14 specimens; Arroyo 

 de Limones, 30 specimens; Arroyo de Taquaco, altitude 4000 

 feet, i specimen; Juan Lisiarraga Mountain, altitude 5500 feet, 19 

 specimens. 



The bulk of the mammal collection from southern Sinaloa is thus 

 from a very circumscribed locality, and probably includes about 

 all the species found there, with the probable exception of a number 

 of species of Bats. It is thus of special interest as thoroughly repre- 

 senting the mammal fauna of a definite area, which thus becomes 

 available for comparison with other well-worked localities, as the 

 limited district in northwestern Durango explored by Batty in 1903, 

 and the nearer localities in northwestern Jalisco carefully worked 

 by him in 1905. A comparison of results shows that of the 40 species 

 (or 37, excluding the introduced species of Mus) obtained in north- 

 western Durango only one, the Gray Fox (Urocyon cinereoargenteus 

 scottii), is found in either southern Sinaloa or northwestern Jalisco, 

 and possibly a Nyctinomus. It is also shown that of the 41 species 

 and subspecies (39, excluding Mus} found in southern Sinaloa only 

 1 6 are included in the 60 species and subspecies taken in Jalisco, 

 although 3 others have representative subspecies in the two regions, 

 notwithstanding that the Sinaloa and northern Jalisco localities are 

 separated geographically by a distance of rather less than 200 miles. 



The Sinaioa collection is perhaps most remarkable in what it 

 lacks, since it contains no Spermophiles, no species of Wood Rat (genus 

 Neotoma), only one species of Skunk (genus Conepatus, Mephitis 

 and Spilogale being both absent), and no species of the family Geo- 

 myidae. None of these could well have been overlooked had they 

 been present. Species of Neotoma and Thomomys are, however, well 

 known to occur not far to the northward of Escuinapa. 



Mr. Batty evidently gave special attention to the larger mammals, 

 these being represented in large series, and are especially welcome as 

 giving unusual opportunity for the study of individual, seasonal, 

 and age variations in a number of species. There are, for example, 

 about 100 specimens of Nasua, nearly 50 of Procyon, 15 of Conepatus, 



[June, 1906.] 13 



