126 [August, 



which is directed backwards. The tail underneath is provided with black patches 

 similar to those in H. texana. 



Locality. Found with the preceding species. 



HoLBRooKiA PROPiNQUA, B. and G. This species, very closely allied to H. 

 mactilata, is most readily distinguished by a more slender form of body and a 

 more elongated tail. Another character is found in the possession of a more 

 depressed and protruding snout. On the sides of the abdomen there are some- 

 times two, but generally three, black patches, whilst in H. maculata these con- 

 ditions are reversed. 



Localities, Between Indianola and San Antonio (Texas.) We possess one 

 individual of the same species, collected by R. H. Kern, Esq., in a more south- 

 westerly locality. 



HoLBRooKiA MACULATA, G. Specimens of this species were obtained on the 

 boundary line between San Antonio (Texas) and El Paso del Norte, thus extend- 

 ing greatly its geographical range. 



Crotaphytus Gambelii, B. and G. Of the size, shape and general appear- 

 ance of G. Wislizenii, from which however it can be readily distinguished by 

 the larger scales both on the back and belly. The head is likewise more ovoidal ; 

 at any rate the plates which cover its surface are larger, especially on the occipi- 

 tal region. The scales on the sides of the head are larger than in C. Wislizenii, 

 especially those of the temporal region. The general distribution of color is 

 the same as in C Wislizenii; the only difference consists in the absence of the 

 small yellowish white dots spread all over the body of the latter species. The 

 transverse yellowish markings appear also to be more conspicuous. 



Locality. Not precisely known; collected by the late Dr. Wm. Gambel 

 during his last visit to California. Specimens also in the Academy of Natural 

 Sciences. 



CROTAPHYTUS DORSALis, B. and G. A small and very characteristic species. 

 The snout is short, truncated or rather rounded, giving to the head a much greater 

 resemblance to that of C. collaris than to that of either O. Wislizenii or C. 

 Gambelii. The scales are proportionally larger than in any of the known species 

 of the genus. Along the dorsal line, a row of still larger and carinated scales, 

 constitutes another very distinctive mark between this species and the others, its 

 congeners. The tail seems rather compressed and is one and a half times the length 

 of the body. The ground color nbove is bluish brown with crowded yellowish- 

 white subcircular spots. The tail is alternately serai-annulated with bluish- 

 brown and yellowish-white. The lower part of the body is unicolor, except 

 under the head, where there are several narrow and oblique bluish streaks. 

 Locality. Desert of Colorado, California. Collected by Dr. John L. LeConte. 

 This species, according to the notes of Dr. LeConte, in running, carries its 

 body very high above the ground, with the tail frequently elevated over the back, 

 somewhat like a squirrel. It runs with very great swiftness, over the sand, 

 making for its hole whenever pursued. 



Uta ornata, B. and G. This species maybe distinguished from U. Stanshn- 

 riana, of which it has the general appearance, by a dorsal space covered with 

 five or six rows of scales larger than those on the sides of the body. Along the 

 middle of the sides there exists one row of small scutollac imitating the lateral 

 line in lishes. The ground color is reddish-brown with transversely elongated 

 black patches all along the upper part of the body and tail. The belly is uni- 

 color in the female, whilst it is blue in the male. 



Localities. On the Rio San Pedro (Texas) and province of Sonora. Speci- 

 mens of the same species were collected by Dr. John L. LeConte at San Diego 

 (Cal.) and San Francisco (Cal.) 



ScELOPORUs PoiNSEXTii, B. and G. Sc. torqnatus var. B. Wiegm.? This 

 species, although more intimately related to Sc. torqnatus than to any other of 

 the same genus, is nevertheless easily distinguishable from the latter by the form 

 and structure of the scales on the middle region of the back, which are subcircu- 



