in the Collection of the British Museum. 23 



Herpetodryas occipitalis. 



Gunth. Ann. & Mag. Nat. Hist. 1868, i. p. 420. 



The example from which I described this species was 

 young, and showed a varied coloration, like many other spe- 

 cies of this genus in their young state. The adult (3 or 4 feet 

 long) is of a uniform dull greenish-olive coloration, this colour 

 extending over the outer fourth of the ventral shields. Middle 

 of the ventrals uniform yellowish. 



Herpetodryas tetratcenia. 



Scales in seventeen rows, all keeled, with the exception of 

 the outermost. Venti-als 150, not keeled ; anal bifid ; sub- 

 caudals 127. Head moderate ; eye rather large. Rostral 

 just reaching the upper surface of the head ; anterior frontals 

 obtusely rounded in front, about half the size of posterior. 

 Vertical as long as the snout, but shorter than the occipitals, 

 which are subtruncate behind. Loreal as high as long ; ante- 

 ocular extending to the upper surface of the head, but not 

 reaching the vertical ; two narrow postoculars. Nine upper 

 labials, the fourth, fifth, and sixth of which enter the orbit. 

 Body greenish olive, with four black longitudinal bands : the 

 bands of the dorsal pair occupy three series of scales outwards 

 of the vertebral series ; they commence behind the neck as a 

 double series of spots, which are soon confluent ; the scales 

 composing its anterior half are black with a narrow white 

 margin, and entirely black posteriorly ; on the tail the two 

 bands are confluent into a single band. The lateral band is 

 narrower, occupying the meeting edges of the second and 

 third outer series ; it commences as a linear, subinterrupted, 

 zigzag tract in the anterior half of the trunk, but soon becomes 

 broader, and is continued to the end of the tail. Upper parts 

 of the head and neck uniform greenish olive ; a broad black 

 band along the side of the head, through the eye. The colour 

 of the side extends for some distance on the ventral shields, 

 which have anteriorly a black transverse margin, interrupted 

 in the middle. 



One specimen from Bogota, purchased. Entire length 

 30 inches, tail 12 inches. 



Philodryas psammophideus. PI. IV. fig. A. 



Habit slender ; head narrow ; eye of moderate size, with 

 round pupil. Rostral shield as high as broad, reaching to the 

 upper surface of the snout ; anterior frontals two thirds the 

 size of posterior. Vertical narrow, much longer than the 

 snout, and as long as the occipitals. Loreal region not 



