ON THE BATRACHIA AND REPTILIA OF COSTA RICA. 125 



62. Basiliscus vittatus, Wiegrn. Herpetologia Mexicana, p. 40, PI. 15, 1834. Corythseolus 



vittatus, Kaup, "Wiegmann. Basilisous, Dume*ril. Basiliscus nuchalis, Cope, Proceed. 

 Academy Philada., 1862, p. 181, (Southern form.) 



Drs. Wiegmann, Wagler, Kaup, and Gray have described only the female of 

 this species, and have established the genus Corythophanes on characters which 

 belong to the female sex only. Prof. Dumeril finds the male to possess the essen- 

 tial features of the genus Basiliscus, and I follow him in referring the species to 

 that genus, as the specimens of the Smithsonian collection abundantly demonstrate 

 the correctness of the view of the French herpetologist. The specimens from 

 Nicaragua and Costa Eica differ from those of the north in their smaller size and 

 larger dermal appendages. This variety I named B. nuchalis. The species ranges 

 north to Vera Cruz. 



Abundant. Numerous specimens from Sipurio. Mr. Gabb, like Dr. Sumichrast, 

 states that this species runs over the surface of the water whose shores it frequents, 

 like a spider. 



The species of the genus Basiliscus known to me differ as follows : — 



I. Dorsal and caudal rayed crests present. 



Two dermal head-crests, the anterior narrow ; both with large scales ; four rows 

 of interorbital scales ; yellow spots ; no longitudinal bands. B. plumifrons. 



One dermal head crest, with large scales ; one row of interorbital scales ; no 

 longitudinal bands. B. mitratus. 



One expanded head crest with small scales ; one row of interorbital scales ; no 

 longitudinal bands. B. guttulatus. 



One tassel-like head crest with small scales ; more than one interorbital row ; 

 no longitudinal bands. B. goodridgii. 



II. A dorsal, no caudal rayed crest. 



A single membranous head-crest covered with large scales ; two or three inter- 

 orbital rows ; one or two longitudinal light bands on each side. B. vittatus. 



III. Neither dorsal nor caudal rayed crests. 



A membranous head-crest of a horizontally elliptic form, covered with large 

 scales ; uniform green. B. seemannii. 



63. Basiliscus plumifrons, sp. nov. 



Represented in Mr. Gabb's collection by five male and one female specimens 

 in fine preservation. It is more nearly allied to the B. mitratus, Daud., than to 

 the B. goodridgii and B. seemanii of Gray, or the B. vittatus, Wiegmann. The 

 abdominal scales are smooth, and both back and tail support elevated crests 

 traversed by osseous rays. The head crest consists of a principal posterior portion 



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