NATURAL SCIENCES OF PHILADELPHIA. 105 



longer than broad, triangular, with rounded angles, separated by two plates 

 from those bounding supraorbital region. One series of interorbitals. Su- 

 praoculars in three series, five in the interior largest. Internasals, two series 

 of four, each followed by two pairs. Scales of the collar but little larger than 

 those anterior ; gular scales equal. A narrow entire suborbital. Eight supe- 

 rior labials, bounded above by two series of similar plates. Eight oblong 

 inferior labials. Symphyseal larger, followed by two trapezoid infralabials. 

 A scapuloinguinal dermal fold on each side. Extended posterior extremity 

 reaching anterior border of ear orifice. Tail broad and depressed at base, 

 slender and slightly compressed, less than twice the length of the head and 

 body. Total length, 21" 4'"; tail 13" 6'"; body 5" 5'"; from collar to 

 end of muzzle, 2" 3'". 



Color above sea-green ; a narrow black cross-band separates the nuchal 

 from the dorsal region ; a broader black band, which presents a convexity 

 anteriorly, crosses the latter anterior to its middle. Between these, some in- 

 distinct undulatory bands, three similar on the posterior dorsal region, fol- 

 lowed by numerous caudal annuli, which become very broad. Beneath, 

 bluish green, darkest on the gular region ; tail and femora beneath yellow. 



Habitat. Cape St. Lucas. From Mr. Xantus' valuable collections. Smith- 

 sonian, No. 6302. 



Sceloporus zosteromus Cope, sp. nov. 



Scales large, strongly keeled, slightly denticulate, in ten longitudinal rows 

 on rump and nape, and eighteen to twenty transverse between those points. 

 Lateral scales larger than abdominal, not granular above and before shoul- 

 der. Auricular scales much longer than those adjacent. Cephalic shields 

 smooth ; prefrontal longer than broad, single ; supraoculars in one series, 

 transverse, posteriorly in immediate contact with superciliary series. Ab- 

 dominal scales emarginate, accumulated on the posterior gular region, where 

 many are tricuspid. Hind limb extended, reaching orbit. 



Length from muzzle to vent, 9" 7 /// ; from muzzle to axilla, 4" 3'" ; hind 

 foot, 3". 



(J 1 Above bright olivaceous, with a reddish longitudinal dorsolateral band 

 on each side, crossed medially by numerous indistinct brown bars, often 

 obsolete. Under surface and sides of tail yellowish. Anterior face of femur, 

 groin, a large spot anterior to brachium, a broad band connecting the latter 

 with the former, and the latter of each side, across posterior gular region, 

 black, which shade into blue on the sides and throat. Chin light-green. 

 Brachium black in front. In younger specimens the prebrachial spot often 

 does not connect with the lateral abdominal band. 



Habitat. Cape St. Lucas. From the collection of Jno. Xantus, Esq. 



A species to be compared with the S. c 1 a r k i i , which is found in Texas 

 and Arizona. The latter has a shorter prefrontal plate, greater size, and dif- 

 ferent coloration. 



Cyclura (Ctenosaura) hemilopha Cope, sp. nov. 

 Ctenosaura sp., Baird, Proc. A. N. S., 1859, p. 300. 

 Breadth just anterior to orbits <yjual to length from line connecting those 

 points to end of muzzle. Rostral plate twice as broad as high, upper outline 

 an arc. Seven premaxillary teeth ; maxillaries (in one specimen) 21, of which 

 six are conic, the third longest, and very few of the remainder more than tri- 

 cuspid. Crest highest on the nape, where it is composed of high compressed 

 processes ; on the anterior fourth of the back they become reduced to a me- 

 dian series of compressed scales, which are undistinguishable behind the 

 middle of the back. Dorsal scales flat ; tibials and antebrachials slightly 

 keeled. Tail cylindrical, the whorls with very strong spines, separated by 

 one series of scales. Foot short, sole not spinous. Length from end of 

 muzzle to gular fold, 6" 5'" ; from mastoid to mastoid, 3" ; from edge of 



1863.] 



