MUSEUM OF COMPARATIVE ZOOLOGY. 189 



Alston's determinations it is evident that specimens he refers to H. longicaudatus 

 present consideraljle variations in color, in the length and hairiness of the tail, 

 etc., and may or may not have white-edged ears. In view of this fact a con- 

 servative course seems the only advisable one in the present instance. 



I may here add that some months since (before the appearance of Mr. Al- 

 ston's revision of the group) I submitted the specimen to Dr. Coues, who 

 considered it as undescribed (an opinion I then fully shared), and returned 

 it with the above-given description and MS. name. 



21. Thomomys talpoides umbrinus (Rich), Coues. Southern Pocket 



Gorniiii. 



Two specimens, San Luis Potosi. " Abundant. Very troublesome in the 

 sugar fields." 



The specimens collected by Dr. Palmer extend the known range of the 

 species much to the southward (some 10° of latitude) and eastward of pre- 

 viously recorded localities (Espia and Santa Cruz, State of Sonora). 



22. Lepus sylvaticus, Bachm. Wood Hare ; " Gray Rabbit." 



Six specimens, from the vicinity of San Luis Potosi. The series includes 

 both young and adult. 



" Everywhere abundant. Brought into the towns by the mule-load." 



23. Lepus callotis, Wagler. Mexican Hare ; "Jackass Rabbit." 

 Eleven specimens, including a series of young examples, from San Luis 



Potosi. 



" Abundant everywhere ; more common even than the smaller species [L. 

 sylvaticus] and forms an important source of food." 



24. Tatusia novemcincta (Linnc). Armadillo. 



There is a single carapace in the collection from the Tierra Calienta of the 

 State of San Luis Potosi, where, according to Dr. Palmer, the animal is not 

 uncommon. 



25. Didelphys . 



Parras, two specimens (skins and skulls in spirits), apparently about half- 

 grown, of a species not yet determined. The ears are entirely white ; there are 

 three prominent black stripes on the face, and the long hairs of the dorsal sur- 

 face are black, imparting this color to the whole dorsal aspect. 



