NATURAL SCIENCES OF PHILADELPHIA. 2G5 



renchoa Wied. Boie, Wagler, Giinther 1. c. p. 174. Dipsas Weigelii Schleg. ii. 



p. 278. Fitz. Syst. Rept., p. 27. 



One sp. Near Isalco, San Salvador. Capt. J. M. Dow. 



Our specimen has the preoculars united, which peculiarity appears to be 

 not uncommon. The dorsal spots connected by a narrow, often irregular 

 brown vitta. 



Tripanurgus Fitz. Type T. leucocephalus. 



Systema Reptilium. 1843, p. 27. 



157. T. leucocephalus Fitz. Coluber leucocephalus Mikan. Col. com- 

 pressus Oppel. Dipsadomorphus comprcssus Fitz. Dipsas leucocephalus Schleg. 

 Lycognathus leucocephalus Dum. & Bibr. Eudipsas leucocephalus Gthr. 

 One sp. V ? 



Dipsas Laurenti. Type D. I n d ic a. 



Specimen Synopsis Reptilium, p. 89, 1768. Dipsadomorus, Petalognathus et 

 Leptognathus Dum. & Bibr. vii. pp. 463, 477, 1854. Leptognathus Giinther, Cat. 

 Brit. Mus., p. 177, 1858. Pholidolccmus Sibynomorphus et Sibynon Fitz. Syst. 

 Rept., 27, 1843. 



The genus Dipsas has been variously understood and defined by herpetolo- 

 gical authors. As four distinct groups have been designated by this name, in 

 order to avoid further confusion we have employed it for that to which it was 

 first applied. In the Synopsis Reptilium of Laurenti, which bears date 1768, 

 the name was first proposed, with an appropriate " character," and D. I n d i c a 

 Laur. was indicated as the typical and only species. In 1852 Dumeril made 

 the same species the type of his genus Dipsadomorus, and in 1858 Giinther 

 placed it in Leptognathus Dum. We next find the genus Dipsas characterized 

 at length by Boie in his invaluable contribution to herpetology, in the Isis von 

 Oken for 1827, and D. cenchoa assigned as the type. This species is the 

 Himantodes of Dumeril, 1852. In the Regne Animal, 1829, we find the genus 

 as proposed by Laurenti retained, and of all modern authors Cuvier is the 

 only one who does so. In 1830 the Naturlich System der Amphibien of Wagler 

 appeared. Here Dipsas dendrophila Rein, is considered typical of the 

 genus ; and in this he is followed by the great ophidiologist Schlegel, in the 

 " Essai," in 1837. The group of which this species is a typical example was 

 named Triglyphodon by Dumeril in 1852, but is the Roiga of Fitzinger, 1826. 



Fitzinger, in the Systema Reptilium, 1843, cites Dipsas cenchoa, 

 ("Weigelii") as the type of the genus, following Boie. Phillippo de Phillippi, 

 in the Catalogue of Serpents in the Museum of the University of Pavia, 1849, 

 follows Wagler and Schlegel. 



In the Prodrome de la Classification des Reptiles Ophidiens, vol. xxiii.of the 

 memoirs of the French Academy, 1852, and afterward in the Erp. Generale, 

 Dumeril considers Dipsas trigonat a the type of the genus. In 1843. 

 Fitzinger proposed Dipsadomorphus for the same species. Finally, in 1858, in 

 the Catalogue of Colubrine Snakes in the British Museum, Dr. Giinther places 

 D. multimaculata first among the species, and so characterizes the genus 

 as to be nearly coextensive with Triglyphodon, Dumeril, including also 

 Himantodes of the latter. 



Believing the genera of Dipsadinas as defined by Giinther, to be, on the 

 whole, more natural than those of other authors, we have adopted them here, 

 simply employing the name Dipsas for that called by him Leptognathus, and 

 Boiga for his Dipsas. 



158. D. nebulata Boie, 1. c. Coluber nebulatus Linn. 1754, Col. variegati/s 

 Hallow. Proc. Acad. Nat. Sci. Phila. ii. p. 244, 1845. Dipsas nebulata Schleg. 

 Essai, ii. p. 275. Sibynon nebulata Fitz. 1. c. Petalognathus nebulatus Dum. & 

 Bibr., 1. c. Leptognathus nebulatus Giinther, 1. c. 



One specimen. Surinam, Dr. Hering. 



One " " Dr. Colhoun. 



Two " Near Caraccas, Mr. Ashmead 



I860.] 17 



