156 3. IGUANID/E 



sdso have pink sacs beneath the throat which are not "in- 

 flated," but are sometimes drawn down by muscles con- 

 nected with the hyoid apparatus. The pink throat sacs are 

 present in only three of the males in the series at hand. 

 The underparts (with the exception of the two black wedges 

 and the blue and green patches of the males) are white and 

 not yellow as in specimens taken at Barstow, farther west. 

 The tail bands number four in one, six in three, seven in 

 three, and eight in 1 1 specimens. The anterior three or 

 four of the ventral tail spots are sometimes entirely blue, 

 and the posterior bands are often margined with blue 

 below." 



Ruthven describes the coloration of specimens collected 

 near Tucson, Arizona, as follows: "There are some dif- 

 ferences in color but not much variation in color pattern 

 among the Tucson specimens of CalUsaurus ventralis. In 

 the darker specimens the ground color above is brownish 

 ash relieved by small spots of light yellow or white. These 

 light spots may be rather distinct or nearly obscured. The 

 head is yellowish brown. There is nearly always a row 

 cf rounded dark spots on either side of the vertebral line, 

 and often a series of indistinct, partially confluent blotches 

 on the sides, that are quite distinct in the young. The 

 lateral blotches are continued on the base of the tail as a 

 dark horizontal shading, that may be broken up into spots 

 which fuse with those of the dorsal series. The latter 

 series are continued onto the tail, the adjacent spots of each 

 row becoming confluent and intensified in color distally, to 

 form about six broad, dark brown or black cross bars. The 

 fore limbs and thighs are generally indistinctly spotted, 

 and the legs and hind feet cross-banded, with darker. On 

 the posterior side of the thigh there is a light yellowish line 

 which is bordered below by a distinct dark band, and above 





