REPTILES OF THE TRES MARIAS ISLANDS. 



69 



SEKPENTES. 



Boa imperator Daudin. 



This is tlie first record of this species from the Tres Marias. The 

 species is generally distributed through southern Mexico and Central 

 America. 



Scale rows 73. 



Litt of specimens of Boa imperator. 



Oxybelis acuminatus (Wietl). 



A common species occurring all through tropical America from 

 Guayinas, Mexico, south. 



List of specimens of Oxybelis acuminatus. 



Diplotropis diplotropis (Gunther). 



This species seems to be confined to western Mexico. It was not 

 collected by Mr. Nelson, but there are two specimens in the British 

 Museum collected by Forrer on the Tres Marias (Leptophis diplotropis 

 Boulenger, Cat. Snakes Brit. Mus., II, p. 110). 



Drymobius boddaerti (Seetzen). 



A common species distributed over tropical America. 



In No. 681 the fourth labials on both sides are divided horizontally, 

 so as to suggest a subpreocular. This is an adult male, and is uni- 

 formly colored above, without any markings. The adolescent specimens 

 are uniform above, with a few scales tipped with black; the anterior 

 part of the underside has square blackish spots. The two young ones 

 have above brown, dark-edged, squarish spots, separated by narrow 

 light-colored interspaces. They are marked underneath like the adoles- 

 cent specimens. 



No. C81, male ad. Scale rows, 17; ventrals, 183; anal, ; caudals, }ff ; 

 supralabials, 9. 



