104 PHRYNOSOMA DOUGLASSII. 



lines; of tail, beyond the vent, I5 inches; of thigh, 7 lines; of leg, 7 lines; of tarsus 

 and toes, 7 lines; total length, 4 inches 10 lines. 



Habits. Mr. Bell* says, on the authority of Mr. David Douglas, who observed 

 it in its wild state, that, "like most others of its tribe, it is very nimble during the 

 summer months, and it is then difficult to capture it; but in April, when it first 

 makes its appearance, or in October, before it retires to its winter habitation, 

 being at both seasons weakly, it is easily taken. At such seasons the traveller 

 is constantly annoyed by them during the night, seeking shelter from the cold 

 under his blanket, and is frequently under the necessity of removing these little 

 intruders on his rest. It takes up its abode in the holes made by a species of 

 Lepus, Arctomys, (Arctomys Richardsonii,) which are alternately occupied by 

 them and several species of Coluber, which resort there for the purpose of 

 preying on these Agamse, (Phrynosomae,) and on the marmots." 



He further states, on the same authority, its food to be coleopterous insects 

 and vegetable substances, as the Purschia, Artemisia, &c.; • but Mr. Nuttall, an 

 accurate naturalist, informs me that he has frequently observed these animals, 

 during a residence of many months in the country about the Oi'cgon river, and 

 that their only food is insects. 



Geographical Distribution. The Phrynosoma Douglassii is abundant in the 

 sandy plains south of the river Oregon, and chooses for its residence the banks 

 of streams that are covered with the Purschia tridentata, Artemisia, Salvia, &c. 



General Remarks. Mr. T. Bell gave the first description of this animal in 

 the Transactions of the Linnsean Society of London, and accompanied it with a 

 tolerable figure, in which the short knobs about the head, instead of long spines, 

 as in the other Phrynosomse, are well represented. The individual from which 



* Trans. Linn. Soc. Loncl., vol. xvi. p. 106. 



