1856.] 231 



tail is round -in Sagrfei it is high and very much compressed, with a dorsal row 

 of larger scales. In acutus the scales upon the abdomen are indistinctly cari- 

 nated, in tropidogaster strongly; the scales upon the frontal region are smooth 

 in acutus, tricarinate in tropidogaster ; tbe supraciiiary ridges are closely in 

 contact in acutus, separated by two rows of scales in tropidogaster. But 

 although these species resemble each other much in color, the most marked 

 point of difference is in the toes, wbich are dilated in acutus, as they most com- 

 monly are in the genus Anolis, but not in tropidogaster. Angusliceps is 

 readily recognized by its small size and narrow head ; heterolepis, by its smooth 

 ventral scales and triangular markirgs, and the arrangement of scales upon the 

 temples, which are composed of granulations and larger scales, as in Sagraei. 

 The two median dorsal rows of scales in acutus are sensibly larger than the 

 others, and the two plates behind the mental, beneath the first and second or 

 pre-labials, broader than those which succeed them. 



After a careful comparison of the descriptions of the species in Dumeril and 

 Bibron, I do not find any which present the saujc characters as those given 

 above. Besides these, Mr. Gray has described seven species, viz. : A. occipi- 

 talis, porcatus, flavescens, lineatopus, stenodactylus, reticulatus, aeneus. Of 

 these the habitat of porcatus is Cuba ; that of aeneus, tropical America. Of the 

 species of which an account is given by me, the most remarkable is A. leuco- 

 cephalus, from the anomalous form of the plates upon the head and the scales 

 upon the body, those upon the sides contrary to what usually obtains, being 

 much larger than those upon the back and abdomen. 



Anolis alligator, Dum. et Bib. 



Char. Head resembling closely that of Alligator; supra-orbitar ridges closely 

 in contact; occipital pla'e in contact with the supra-orbitar ridge; scales upon 

 temples ot unequal size, with an anterior marginal row of larger scales; two or 

 three middle dorsal rows of scales larger than the others; small granules inter- 

 spersed between the scales upon tbe body ; ventral scales smooth ; no dorsal or 

 caudal crest; tail slender, slightly compressed at its middle ; color dark bluish, 

 with black maculaiions; a black spot beneath each axilla. 



Description. Head not elongated, stout, thick at base, front very slightly 

 ridged, with a depression in the middle, covered as well as the muzzle with 

 rough but not carinated scales ; rostral broad and narrow ; immediately behind 

 it two large quadrangular plates, with a smaller one between ; posterior to this 

 transverse row two longitudinal rows of quadrangular plates ; front covered 

 with polygonal plates of unequal size, many of them quite large; nostrils large, 

 subeircular, rather more than half a line from the extremity of the snout, situ- 

 ated within the continuation of the supra-orbitar ridge, at the anterior extremity 

 of a slight prominence ; supra-orbitar ridge composed of five large plates, rough, 

 but not carinated, with two smaller ones bebiud the anterior by far the largest; 

 the two ridges closely in contact; from five to eight or nine supra-orbitar plates 

 not carinated, separated from the supra-orbitar ridge by a single row of small 

 scales; occipital plate urceolate, with large scales laterally, smaller ones behind, i?i 

 contact in front with the supra-orbitar ridges; eight quadrilateral plates margin 

 the upper jaw on each side ; three rows of scales above the marginal plates, in 

 front of the orbit, the inferior the largest ; scales upon the temples of very unequal 

 size, with a distinct anterior marginal row of larger scales ; auricular openings rather 

 large, denticulated ; body rather stout, covered above with scales elevated in the 

 middle, but not carinated; the two or three middle rows a little longer than the others ; 

 scales upon the flanks smaller than those upon the back, but not granulated ; each scale 

 upon thz body is surrounded by very small and scattered granulations, resembling in 

 size, though not so closely approximated as in Varanus ; ventral scales smooth, larger 

 considerably than those upon the body, rounded posteriorly ; no crest upon neck 

 or back; tail longer than head, neck and body, thick at base, slightly compressed 

 at its middle, very slender except toward base, covered with carinated scales ; 

 above a large median row, almost smooth beneath, and of nearly equal size in 

 tho specimen examined, except five or six rows ou each side, about 5J lines 



