132 University of California Publications in Zoology [ VoL - 10 



differs from it in much smaller size throughout, particularly 

 small hands and narrow rostrum, and in browner color. Re- 

 sembles Scapanus anthonyi 3. A. Allen (1893, p. 200; see also 

 True, 1896, pp. 53, 57, pis. 1-3) in small size, but differs from it 

 in paler coloration, slightly different dimensions, narrower 

 cranium in interorbital region, extremely narrow rostrum, and 

 in presence of all four upper premolars. 



General Remarks : In dentition all of the available material 

 of the new form shows the condition normal in latimanus, save 

 that in one (no. 2733) one upper unieuspid on the left side is 

 wanting, apparently the canine. In all, the first upper premolar 

 is much reduced in size, and the unicuspidate teeth are irregu- 

 larly spaced, in these respects as well as in others, differing 

 decidedly from Scapanus townsendi of the northwestern corner 

 of California. 



So far as we are aware, the only specimen of S. anthonyi 

 thus far obtained in any collection from Lower California is the 

 type. This specimen is described and figured in greatest detail 

 by True (1896). There are some discrepancies in the measure- 

 ments as given by Allen (1893, p. 200) and True (1896, p. 67), 

 but discounting these, there remain sufficient differences in 

 proportions of the cranium to provide alone an adequate basis 

 for separation of occult lis from anthonyi. 



The new form is fifteen per cent smaller than latimanus. 

 The individuals examined are remarkably uniform in all respects. 



1 2 



Pig. 1. Eight hand of Scapanus latimanus latimanus (Bachman), 5; 

 no. 3859; La Honda, San Mateo County, California. X 1.33. 



Fig. 2. Eight hand of Scapanus latimanus occultus, new subspecies, $; 

 no. 2089; Strawberry Valley, San Jacinto Mountains, California. X 1.33. 



