36 CALIFORNIA ACADEMY OF SCIENCES. 



single supracaudal plate. Plastron large, extending for- 

 ward beyond the carapace, notched posteriorly and 

 sometimes anteriorly. Gular plates smallest, sometimes 

 united, covering a narrow process of the plastron, which 

 may be level or curved upward. Pectorals very much 

 smaller than abdominals, with shortest median suture, 

 except sometimes that of anals. Abdominals largest, 

 with longest median suture. Humerals larger than 

 femorals. Anals little longer than gulars. Axillary 

 and inguinal plates well developed, latter varying from 

 two to six, not extensively wedged in between abdom- 

 inals and marginals. Head rather elongate, not very 

 wide, covered above with flat scales larger anteriorly 

 than posteriorly. Upper jaw not hooked, margins 

 nearly straight, irregularly but finely serrate. Skin of 

 neck with flattened granules. Anterior limbs large, 

 heavy, much expanded laterally, covered in front and 

 externally with large, hard, smooth scales, and provided 

 with five stout claws.* Posterior limbs not compressed, 

 covered around the edge of the circular sole with large 

 scales, and provided with four stout claws. Tail very 

 short, slender distally. 



The carapace is brown or horn-color, usually relieved, 

 especially near the centers of the plates, with yellow. 

 The head and limbs are brown. The plastron is yellow, 

 shaded with brown along the edges of its plates. 



Length of carapace 215 260 285 310 



Length of plastron 210 265 285 300 



Width of carapace 160 212 2.30 240 



Width of plastron 148 184 210 209 



Distribution. — The Desert Tortoise is known only 

 from the desert portions of southeastern California, 

 southern Nevada, and probably Arizona.! It has been 



*In one specimen the outer three claws of the right foot are united. 

 t Cox, Am. Nat., XV, 1881, p. 1003. 



