18 University of California Puhlicatious in Zoology [Vol. 21 



those that live in. the tule marshes along streams. Specimens from 

 Butte Creek and Chambers Ravine are not typical aestuarinus, but 

 are apparently intergrades with mariposae. Those from Snelling can 

 best be referred to as intergrades between mariposae and aestuarinus. 

 The original description of " Arvicola edax" was published by 

 Le Conte (1853, p. 405) as follows: 



2. Arvicola edax. . . . 



Hob. In California. 



Body short and thick. Hair plumbeous black [= underfur?], above and on 

 the sides tipt with shining brown mixed with black, beneath tipt with grey. 

 Head short, blunt, ears round, not entirely concealed under the fur, hairy within 

 and without, antitragus large, semicircular. Feet covered with short, shining 

 gray hair, thumb, tubercle, with a short, very blunt nail. Tail moderate, hairy, 

 above, dusky beneath, grey, with a slight tinge of brownish. 



Length as before, in. 5.5; head 1.4; ears .5; foreleg 1.3; hind leg 1.5; tail 1.5. 



4701 

 This description fits the type specimen (no. -^^^ U. S. Nat. Mus.), 



but is so broad that it does not definitely place it with what has been 

 currently known as edax. In skinning and preparing the type speci- 

 men the base of the skull was cut away, as was often done in former 

 days so as to remove the brains. The type was an immature indi- 

 vidual, but contrary to the statement of Bailey (1900, p. 38) it is not 

 of the large swamp race. The dentition agrees in every respect with 

 skulls of the same age from Monterey and other places within the 

 range of what is here regarded as calif ornicus. The skull itself agrees 

 much more closely with skulls of the same age from the coast south 

 of Walnut Creek than it does with those of "edax" [= aestuarinus]. 

 The skin possesses no characters by which it can be distinguished from 

 fresh skins from Monterey. Other individuals from the coast south 

 of San Francisco have feet the same size as those of the type of edax. 

 The measurements of the type as given by Le Conte, but converted 

 into millimeters, are : total length, 139.7 ; tail, 38 ; Avhile the dried foot 

 now measures 23.1. 



Dr. T. S. Palmer in conversation with the present writer informed 

 him that Le Conte secured his specimens from George Horn and 

 William Gambel. Dr. Horn is known to have collected at Fort Tejon 

 while Gambel collected at Monterey and Los Angeles. Neither the 

 skin nor the skull of the type of edax agrees with either hernensis 

 (the race represented at Fort Tejon) or neglectus (the race at Los 

 Angeles), but both agree with the central coast form calif ornicus, 

 particularly with specimens of it from Monterey. For this and other 

 reasons cited above, the writer believes it necessary to place edax in 

 the synonymy of calif ornicus. as elsewhere indicated. 



