1856.] 233 



scales, with a broad pentagonal one behind them ; a few small scales between 

 the large snpra-orbitar plates four or five in number and the supraciliary 

 ridge ; five or six narrow quadrangular supra-labial plates, the fourth the longest ; 

 a long and smooth plate below the orbit, in front of it five others, the second, 

 counting from the nostril, the highest, the first immediately below the nasal 

 plate ; beneath these plates and above the supra-labials a row of smaller plates; 

 eyelids covered with granulations; mental plate triangular, five or six inferior 

 labials ; 36 teeth in the upper jaw, the seven or eight posterior tricuspid, the 

 others pointed, conical, the anterior quite small; 40 in the lower, the twelve last 

 tricuspid; a row of small palatine teeth, one on each side ; tongue triangular, 

 smooth above, deeply notched posteriorly, very slightly so in front; tympanum 

 circular, of moderate size, somewhat depressed ; neck slightly folded upon its 

 sides; body moderately robust, covered for the most part with large scales 

 broader'than long, unicarinate, the carinae strongly developed ; the median 

 dorsal row larger than the others, tectiform ; extremities slender, covered with 

 carinated scales ; third and fourth fingers of equal length ; fourth .toe much the 

 longest ; tail cyclo-tetragonal at base ; no femoral and no anal pores. 



Coloration. Greyish white above, upon head, back and extremities brownish; 

 beneath of same color, except upon chin and throat and sides of abdomen, which 

 are of a beautiful pink red color. 



Dimensions. Length of head 8 lines ; greatest breadth 6 ; length of neck and 



body to vent 1 inch 8 lines ; of tail ; of humerus 5 lines ; of forearm 4 



lines ; of hand to extremity of longest finger 6 lines ; of femur 6 lines ; of tibia 

 7 lines ; of foot to extremity of longest toe 1 inch. 



Ilabitat. New Grenada. One specimen received from Philadelphia Museum 

 in exchange. 



Gen. Remarks. The genus above characterized differs from Sceloporus, among 

 other particulars in being destitute of femoral pores, in the presence of the row 

 of larger scales along the median line of the back, and in the scaling of the 

 head ; from Proctrotretus, in having carinated and not smooth scales upon the 

 abdomen, as well as in the two last mentioned particulars. In Ophryessa, in 

 Enyalius, Wagl., and in Microlophus, there is a larger row of scales along the 

 median line of the back, and in Dipso-saurus also, to which it has little or no 

 other resemblance ; but in Ophryessa the scaling of the head is quite different, 

 presenting numerous small and rough polygonal tubercles above ; the scales 

 upon the back are not so broad, and are much more strongly carinated. Ophry- 

 essa is a much larger animal, and has a well marked though not elevated crest. 



Gen. PROCTROTRETUS, Dumeril et Bibron. 



Char. Head subpyramido-quadrangular, more or less depressed, cephalic 

 plates moderate, polygonal, occipital in general not very distinct; palatine teeth ; 

 neck folded upon the sides, or entirely simple; tympanic membrane slightly de- 

 pressed ; body rounded or slightly depressed, covered with imbricated scales, 

 the superior carinated, the inferior smooth ; neither caudal nor dorsal crest ; 

 toes simple ; tail long and conical, or moderate, slightly depressed ; no femoral 

 pores ; anal pores in the males. D. & B. 



Proctrotretus niger, nob. 



Char. Of small size; color black or dark brown above. Scales of moderate 

 dimensions, quadrangular, strongly carinated, the margin of the scales distinct; 

 a fold upon the side of the neck, bifurcating anteriorly ; temples covered with 

 scales ; post-auricular regions with granulations, and sides of the neck with 

 small scales ; a single row of plates above the supra-labials ; posterior surface of 

 thighs granulated. 



Description. Head small, depressed, with a rather acute snout, covered above 

 with polj'gonal, unequal scales, not carinated ; immediately behind the rostral 

 are three plates, the two external much more extended transversely than the 

 middle ; behind these are three others, the two lateral more extended longitu- 

 dinally, and more narrow than the middle one ; exterior to these lateral plates, 



