308 U. S. NATIONAL MUSEUM BULLETIN 206 



panic ridge; a pair of prominent oval glands on each side of tlie anus; 

 ventral surface smooth except the lower and posterior surfaces of 

 thighs which are slightly granular. A slight skinfold across the 

 chest between the axillae. (No external vocal sac in the male, but 

 a prominent ridge on the tip of the snout.) 



Dimensions. — Head and body 25 mm.; head length 8.5 mm., width 

 9 mm.; femur 10 mm.; tibia 11 mm.; foot 10.5 mm.; hand 5.5 mm. 



Color in alcohol. — Dorsum faded to pale buff; a trace of sepia on 

 the canthus rostralis, and a narrow sepia line leaving the posterior 

 corner of the eye, passing above the tympanum, and breaking up on 

 the sides into a series of dots which continue to the groin; above 

 this a broad immaculate light stripe, of which the upper border is 

 again dotted with sepia vermiculations, fainter anteriorly; lateral 

 anal region with some sepia markings, and traces of crossbars on 

 upper surface of forearms, femur, and tibia, stronger on the last; 

 posterior femur faintly reticulated with sepia; ventral surface immacu- 

 late pale buff. 



Color in life. — Based on USNM 96943, immature cotype (in Lutz, 

 1926b, pi. 32, figs. 14, 15). Ground color of back and head clove 

 brown, lighter on canthus and tip of snout; a clove-brown lateral 

 stripe from tympanum halfway to groin, above it a wide, dorsolateral, 

 orange-vermilion, lateral stripe from eye to groin, and another nar- 

 rower middorsal one of the same color beginning between the shoulders 

 and widening in front of the anus; upper arm, elbow, and heel orange 

 vermilion; upper surface of femur and tibia dull sage green with dark 

 crossbars, feet and hands paler but similarly barred. 



Variations. — In six topotypes from the same series as the described 

 specimen, a fair degree of uniformity is observed in most characters. 

 The snout is uniformly blunt and romided when seen from above, 

 the difference in sex seeming to affect its length very slightly, al- 

 though in profile the males show a distinct transverse ridge that is 

 highly modified or lacking in females. The interorbital diameter is 

 from 1)^ to 2 times the width of the upper eyelid, while the nostril 

 may be midway between eye and tip of snout, or considerably nearer 

 to the latter. Head width and length (from posterior border of 

 tympanum) are usually equal, although the width is a trifle greater 

 than the length in the described cotype. The skin is usually very 

 smooth; in only one of the topotypes is there a faint suggestion of a 

 dorsolateral glandular line. 



Practically the same variations are met v/ith in specimens from 

 the States of Sao Paulo and Rio de Janeiro. Wherever the color 

 pattern still shows, every intergrade can be found from the strongly 

 striped form figm-ed as typical L. trivittatus by Dr. Lutz to a spotted 

 form without a trace of dorsolateral stripes (except perhaps for a dark 



