342 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



A half-grown male (No. 20,536, U.S.N.M.), taken at Monument No. 

 66 (Lang's Ranch), in the Animas Valley, had acquired the winter coat- 

 ing to the posterior half of the body as early as July .">. This illus- 

 trates the importance of excluding young individuals when studying 

 seasonal changes of pelage in mammals of warm countries. 



Remarks. Four specimens from Belen, on the Rio Grande, in 

 Texas, have remarkably long tails, with considerable terminal black 

 on them. They are a good step from typical C ludomcianus toward 

 ( '. mexicanus. 



Habits and local distribution. — Capt. John (i. Bourke, V. S. A., 

 in an account of the Arizona Flora and Fauna." writing of the region 

 about ( )ld Camp Grant, on the San Pedro River, Arizona, says: 



And so with the animal life; the deer, of the strange variety called "the mule;" 

 the coyotes, badgers, polecats, rabbits, gophers, but not the prairiedog, which, for 



some reason never underst 1 by me, does not cross into Arizona, or, to be more 



accurate, does just cross over the New Mexican boundary at Fort Howie, in the 

 southeast [Cynomys ludovicianus arizonensis], and at Tom Ream's ranch, in the Moqui 

 country, in the extreme northeast [Cynomys gunnisoni]. 



In the year L885 I observed immense colonics of Arizona prairie- 

 dogs in the region contiguous to the Southern Pacific Railroad in 

 southeastern Arizona, extending as far west as the town of Benson, 

 on the San Pedro River. Other colonies were located in the region 

 about the junction of the Gila and Salt rivers, also in the Sulphur 

 Spring Valley. For miles the burrows of these animals are thickly 

 scattered over the plains south of the Pinaleno Range or Sierra Bonito, 

 where the soil is clayey and better suited to the habits of this animal 

 than the loose sand of most of Arizona. Here the "dogs" fairly rev- 

 eled and overran the country. As we rode amongst them their sharp 

 barking was incessant and their tameness surprising. \Ye had no 

 difficulty in obtaining as many specimens as we desired, as they were 

 easily killed with shotguns, although, from the form of their burrows, 

 many rolled out of reach before we could secure them. The burrows 

 descend at first obliquely for two or three feet, then make a sudden 

 bend in the opposite direction, so that, even when shot dead, their 

 rotund bodies will double tip and roll down the incline past the tingle 

 out of reach simply by force of gravity. We found that a shot deliv- 

 ered from exactly in front of the animal as it sat at the top of its 

 mound with head and shoulders above the rim of earth that formed 

 a breastwork around it. would almost always kill it instantly. A 

 good many occupied-burrows bad no mounds whatever around them. 

 1 saw three adults enter a single burrow, and Dr. Paul Clendennin, 

 l'. S. A., who accompanied me, killed two at once that were barking 

 together in the same hole. 'White-necked ravens (( brvus cryptolt ucus) 



"On the Border with Crook. 2d ed., 1892, p. 9. 



