368 University of California Publications in Zoology [Vol. 12 



431) that the tail is "above sepia, beneath white", has no founda- 

 tion in fact, as the specimens show the regulation two dark stripes, 

 one above and one below, with an intervening white stripe on each 

 side. It is rny impression that the specimens from Sites are a trifle 

 lighter than those from Ukiah, especially in the face, but the shade 

 of difference is so slight that I should call them both calif ornicus and 

 simply say that individuals from Sites show a tendency toward an 

 extreme of light coloration for the species. 



Habitat. — As far as the present geographical distribution of 

 Dipodomys c. trinitatis shows, the stock form may have originally 

 worked up over the comparatively low divide from the head of the 

 Sacramento Valley and then differentiated, because of approximate 

 isolation, spreading in like manner to the north and east. George 

 Knowles stated that kangaroo rats occur at Hay Fork, Trinity 

 County; but as far as our present material goes we have no other 

 actual record than those from the two localities at which we col- 

 lected specimens. 



At Helena we trapped for Dipodomys on the north side of the 

 Trinity Eiver near its junction with the north fork. For a short 

 distance above this junction small sandy flats extend back from 

 the banks of the river, due partly to hydraulic mining carried on 

 in earlier days. With this exception the river runs through a nar- 

 row, rocky canon, so that it would seem as if Dipodomys had here 

 found a very limited area siiited to its needs. The area of our 

 trapping did not cover over half a mile, and was confined altogether 

 to the north bank. "We crossed the river at one point, about a mile 

 above the junction, but although there was a sandy flat there and 

 conditions seemed to be ideal for Dipodomys, we found no signs 

 of them whatever. Where we did trap them, sign was plainly to 

 be seen, consisting of burrows and the tracks of the animals. The 

 prints of the hind feet showed at intervals of about twenty inches, 

 directed to or from clumps of bushes, or around them. These 

 bushes were manzanita and willow, and under them we set our 

 traps. The holes were filled up with sand, evidently by the ani- 

 mals. Trapping was more likely to be successful when done near 

 these holes, even though they did not look as though recently used. 

 Many of the Dipodomys secured had succeeded in filling their cheek 

 pouches full of oatmeal before being caught. 



Our trapping area at Scott River was not much more extensive 



