60 JUnJSIOX OF AMERICAN MOLES— TRUE. 



has shed only on the head and breast, but new fur is elsewhere cou 

 cealed under the old. A female from Olancha, Owens Lake, Calif<jriiiii 

 (altitndo 3,700 fi-et), taken June 12, has new fur on the breast and head 

 and along the middle of the back. In a male from San Uernardiiio, 

 Cal., captured June 7, the change has gone a little further, involving 

 nearly the entire upper surfaces and the nnder surfaces as far as the 

 middle of the belly. It is rather surinising to Hnd that a male from 

 Alhand)ra, Los Angeles County, California, taken June 21, has not 

 changed at all, the new hair reaching up only to the middle of the old, 

 and this only on the back. 



INDIVIDUAL VARIATION IN Sf'APANI'S. 



There are two kinds of variation which maybe termed "individual," 

 one a congenital variation and the other ac(piired. Of congenital vari- 

 ation, there does not seem a great deal among the Pacific Coast moles. 

 A specimen of S. californuufi from Alhambra, California (a male), and 

 one from Cazadero (a iemale) have a small line or tawny-white mark on 

 the left side of the face. This probably represents incipient albinism, 

 and is congenital. 



Acquired variati(ms in color arise from staining by secretions, fading, 

 etc. Where these aflect the whole body, it is not always easy to deter- 

 mine whether they are accidental or seasonal. When the lower part 

 of the hairs, which are ordinarily pure plumbeous gray, is affected, it 

 may, I think, be sujiposed that the alteration is accidental and due to 

 external causes. Thus, three skins of ^'. cidifornicus from Alhambra, 

 California, exhibit large areas, on the back and elsewhere, of a bright 

 l)ron/y color, which color affects, to a certain degree,*the lower part of 

 the hairs, Avhich are far from being pure gray. A specimen of (S. ton-n- 

 sendi from Seaton, Oregon, taken October 5, shows a somewhat similar 

 suffusion over nearly the whole body, though it is less conspicuous, as 

 the Oregon moles are very dark-colored. In this instance the discol- 

 ored fur is old fur, the new fur appearing at its roots. 



Several specinjens small show tufts here and there of fur which is 

 whitish or tawny througliout, as is sometimes seen in ISadojt-s. These 

 spots do not seem to be due to age. 



The most noticeable individual variations in the skulls are those 

 which affect the teeth. These variations are few in nund)er and consist 

 in reductions of the normal number of teeth. Only four cases of this 

 kind are to be f(mnd anu>ng the skulls which I have examined. A skull 

 of /S'. caUforniciis from San Gabriel, California, lacks the first upper pre 

 molar on the right side.' One from Xicasio lacks the third upper inci 

 sor on tlie leftside, and another from the same locality lacks the second 



• It is not always possible to rtetermine the proper name of the missing tooth. 

 When a premolar is lacking, for example. Ihe remaining teeth frequently change their 

 normal position, so that no large hiatus is left. 



