REPTILES OF THE PACIFIC COAST. 35 



found in the San Francisco markets. In each instance 

 the market-men told me that the turtle had been sent in 

 with fish from the San Joaquin River near Stockton, 

 California, but, when questioned, could not state pos- 

 itively that the lot had not come from Oregon or Wash- 

 ington. 



Genus 3. GOPHERUS. 



Xerobaies, Agassiz, Coutr. Nat. Hist. U. S., I, 1857, p. 446 (types 

 polyphemus nud berlandieri) . 



The shell is very broad and higli. The plastron is 

 immovably united to the carapace by a broad bridge. 

 There is a ridge along the middle of the alveolar surface 

 of each side of the upper jaw parallel to the cutting 

 edge, except in front, where there is a longitudinal ridge 

 at the symphysis. The internal openings of the nostrils 

 are between the eyes. The limbs are club-shaped, the 

 fore limbs flattened, without webs. The skin on top of 

 the head is divided into scales. There is but one supra- 

 caudal plate. 



3. — Gopherus agassizii (Cooper). Desert Tortoise. 



Xerobates agassizii, Cooper, Proc. Cal. Ac. Sci., II, 1863, p. 120 

 (type locality mountains of California near Fort Mojave); 

 True, Proc. U. S. Nat. Mns., IV, 1881, p. 437. 



Testudo agassizii, Boulenger, Cat. Chelonians Brit. Mus., 1889, p. 

 156. 



Gopherus agassizii, Stejneger, N. A. Fauna, No. 7, 1893, p. 161. 



Description. — Shell broad and deep, often flattened 

 above, its margin serrate all around, except in worn 

 specimens, and usually more or less rolled upward over 

 limbs. Growth-center of each plate smooth, but usually 

 surrounded by beautifully ribbed shell. Vertebrals five, 

 last largest and widest. Costals four, first longest, sec- 

 ond and third about equally high, last smallest. Nuchal 

 not much narrower than long. Marginals eleven and a 

 half on each side, last pair being united to form a 



