HERPETOLOGY OF PORTO RICO. 631 



Description. — Adult male. Mu.s. Comp. Zool. Cambr., Ma.s.s., No. 

 6167; Porto Rico; Dr. Stahl, collector. Top of head flat, with only 

 shallow depressions on prefrontal and occipital region, the scales 

 being rather small and roughly keeled and tuberculated, even those on 

 top of the snout, but especially those of the supraorbital semicircle 

 and frontal ridges; about nine enlarged supraoculai's, flat, keeled, and 

 in contact with the semicirculars; supraorbital semicircles separated 

 by about three scale rows from each other and from the occipital, 

 which is barel}" noticeable; scales surrounding the occipital depression 

 on the sides and behind rather large, flat, polygonous, each with a strong- 

 keel; six loreal rows, the scales composing the lower row next to the 

 supralabials largest; one row of large keeled suboculars; 7-8 supra- 

 labials to under the center of the eye; temporals flat, with a low 

 tubercle, all the scales of the sides of the head being more or less 

 rugose or wrinkled; ear-opening rather small, upright, oval; back and 

 sides covered with uniform scales tuberculated or keeled, separated 

 from each other by one or more rings of minute granules; on the 

 median line of the neck and back a series of about fifty triangular 

 spines forming a saw-tooth ridge scarcely connected with the caudal 

 crest; ventral scales about same size as dorsals, though more closely set, 

 but not keeled or distinct!}' tuberculated except on the flanks; scales 

 on chin and throat more elongate, distinctl}'^ keeled or tuberculated; 

 scales on upper side of fore limbs larger than dorsals, juxtaposed or 

 imbricate, keeled, becoming larger and multicarinate toward the hand; 

 scales on upper side of hind limb similar, though less sharply keeled; 

 scales on under side of femur slightly larger than ventrals, indis- 

 tinctly tuberculate; digital expansion well developed, about thirty- 

 three lamellae under second and third phalanges of the fourth toe; tail 

 strong!}' compressed, basal half with a high fin-like crest supported by 

 about fourteen bony "rays," the elongations of the neural spines of 

 the caudal vertebrae; scales covering sides of tail flat, keeled, those 

 on the fin between the "rays" elongate, three to four rows between 

 rays, about fourteen longitudinal rows on side of tail at the level of 

 the fifth ray from the base; gular appendage very large, with distant 

 rows of small tul)erculate scales on the naked skin, the edge being 

 rounded, thickened, and scaly; large postanal plates. 



Dimensionfi. '""»• 



Total length 402 



Snout to anus 126 



Anus to end of tail 276 



Snout to ear-opening 42 



Greatest width of head 24 



Fore limbs 59 



Hind limbs 96 



Tibia 34 



