•'-544 Univi rsity of California Publications in Zoology [Vol. 10 



accrue from the smallness of the series involved, rather than to 

 lie of any deeper significance. 



From Snow Creek, up in the foothills three miles southwest 

 of Whitewater, there are thirteen specimens, including adults 

 and young. These are distinctly paler than the average of the 

 Cabezon and Banning series. All, in fact, are to be matched 

 from desertorum in seasonally comparahle pelage. In amount 

 of black dorsally and white ventrally, tint of yellowish In-own 

 laterally, and dorsal color of tail, we are unable to distinguish 

 them from desertorum. Also is this true in quality of pelage. 

 though the series is in worn breeding stage, and hence not so 

 soft as desertorum is in fresh fall pelage. In size some Snow 

 Creek examples are well toward the upper limit of the range 

 of variation in intermedia: the series averages large. Cranially 

 old adult males are still large, like the ones from Cabezon and 

 Banning, though not so large and long-snouted as intermedia 

 proper. The audital bullae remain small, but with evident varia- 

 tion. 



From Whitewater station, on the floor of the desert sloping 

 up toward San Gorgonio Pass, and only three miles from the 

 station at Snow Creek, there are nine, mostly young. These all 

 show the small size, pale coloration, and soft pelage of typical 

 desertorum. [See charts showing variation in measurements. 

 figs. \-c, which take account only of adults.] Cranially we 

 can see no difference from desertorum, except in audital bullae, 

 which are appreciably smaller. This difference, however, van- 

 ishes when selected examples of <l< si riorum are lined up with 

 the Whitewater crania in proper sequence; in other words, while 

 there is average difference in this respect, individual variation 

 (or the results of interbreeding) bring an overlapping or inter- 

 gradation. From intermedia and gilva from Banning, the White- 

 water crania are markedly distinguished by lesser bulk and 

 shortness of rostra and nasals. 



Unfortunately we have from Palm Springs, well out on the 

 floor of the desert, but one example. This in all respects, includ- 

 ing audital bullae, is quite typical of desertorum. It is note- 

 worthy that an obvious intergrade between des( rtorum and inter- 

 media has been described from Palm Springs. This is "Neotoma 



