SCIURIDA—CYNOMYS LUDOVICIANUS. 897 
‘Dogs’ in any portion of the Red River Basin, and the probability is that the 
animal has made little if-any settlement so far eastward in this latitude. I 
found some small colonies, however, at various points in the Milk River 
region, which may really be the limit of dispersion to the northward. The 
most extensive establishment was in a tolerably fertile depression of the 
prairie just east of Frenchman’s or White Earth River, about lat. 48° 
30’, and not far from the mouth of Milk River. The owls, Speotyto hypogea, 
rattlesnakes, Crotalus confluentus, and horned frogs, Phrynosoma douglassi, 
are also inhabitants of the same area, though never seen in the Red River 
water-shed. These four animals, and the Sage Cock, Centrocercus urophasi- 
anus, are almost diagnostic of the Missouri Basin as distinguished from that 
of the Red River.” 
At the southward, according to Lieutenant Abert, as quoted by Audubon 
and Bachman, this animal “does not hibernate, but is out all winter, as lively 
and as pert as on any summer day”. Gregg also states that he had good 
authority for the statement that they are always abroad in winter during fine 
weather. According to Lewis and Clarke, however, ‘as soon as the frost 
commences, they shut themselves up in their caverns, and continue till the 
spring opens”. Say also says that “they pass the winter in a lethargic sleep”, 
defending themselves from the inclemency of the season ‘by accurately 
closing up the entrance of the burrow”. This is doubtless a mistake, as, in 
January, 1872, I met with them in Northwestern Kansas as active on bright 
sunny days as in summer, they only retiring for a few days at a time during 
the severest weather. Further northward, where the climate is more severe, 
they are doubtless less active in winter than further southward, retiring to 
their burrows for longer periods. 
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