SAURIA—IGUANIDAE— PHRYNOSOMA PLANICEPS. 593 



pearance. A certain slight means of defense which the "horns" may some- 

 times afford is shown by the nse they are put to when the animal is irri- 

 tated by poking with a finger or bit of a stick ; then the head is lowered, 

 the horns set forward, the back arched up, and the whole attitude becomes 

 ludicrously like that of a bull in miniature. The Horned Lizards show 

 special aversion to dogs ; on the approach of one, they raise themselves to 

 the full length of the legs, puff out the body, open the mouth, and hiss 

 audibly, altogether presenting quite a formidable front, Their food, in 

 confinement and otherwise,- consists chiefly of flies and other insects, which 

 they capture by a quick thrust of the fleshy tongue, lubricated with viscid 

 saliva. I have not observed the time of coition, nor the period of gestation; 

 but most of the females are found pregnant in July, and the young appear 

 in great numbers in August. The male is usually smaller than the female, 

 and of slenderer form. 



7. Phrynosoma regale, Gir. 



Phrynosoma regale, Gir., Herp. U. S. Exp. Exped., 185S, 40G. — Bd., U. S. & Mex. 



Bound. Surv., ii, pt, ii, 1859, Reptiles, 9, pi. 28, figs. 1-3. — Cope, Proc. 



Acad. Nat. Sci. Phila., IStiC, 310.— I,/., Check-List, 1875, 49. 

 " Plwynosoma Solaris, GRAY, Cat. Sauria Brit. Mus., 229." 



This large species, not noted by me, appears to inhabit more particu- 

 larly the desert portions of the Territory in the valleys of the Gila and 

 Colorado. 



8. Phrynosoma maccalli, (Hallow.) Cope. 



Anota WCalli, Hallow., Sitgreave's Exp. Zufii & Col. Riv., 1853, 127, pi. 10, (type of 



genus). 

 Doliosaurus mc'callii, Gir., Herp. U. S. Exp. Exped., 185S, 400.— Bd. U. S. & Mex. 



Bound. Surv., ii, pt, ii, 1S59, Reptiles, 9, pi. 28, tigs. 4-0. 

 Phrynosoma maccallii, Cope, Proc. Acad. Nat. Sci. Phila., I860, 310. — Id., Check-List, 



1875, 49. 



From the same region as the last, and, like it, not noticed by me. 



9. Phrynosoma planiceps, Hallow. 



Plate XXIV, fig. la, lb. 

 Phrynosoma planiceps. Hallow, Proc. Acad. Nat. Sci. Phila., 1S52, 178. — Cope, Check- 

 List, 1875, 49. 



This species has been added to the fauna of the Territory by Dr. II. (J. 

 Yarrow since the present paper was drawn up. 

 38 z 



