354 Dr. A. Giintber on neiu Species of Snakes 



Xenodon irregularis. PI. V. fig. D. 



Similar in habit to X. severus. Head broad, rather depressed, 

 with the snout short ; eye of moderate size. Rostral broader 

 than high, reaching the upper surface of the snout; vertical 

 nearly as broad anteriorly as long ; occipitals small, somewhat 

 longer than the vertical. Loi'eal quadrangular, as high as long. 

 One elevated prseocular, reaching the upper surface of the 

 head; a second, minute one, below, excluding the third labial 

 from the orbit ; three or four postoculars. Seven upper labials, 

 only the fourth of which enters the orbit. There are about 

 seven temporals on each side, which are rather irregularly 

 arranged ; the foremost is the largest. Scales in nineteen rows, 

 one-grooved : those of the vertebral line are somewhat larger 

 than those on the sides; those of the six following series are 

 narrow, the remainder rhombic. Ventrals (147-)153; anal 

 bifid; subcaudals 36. 



An adult specimen from Para, 43 inches long (tail 5 inches), 

 is uniform brownish grey above ; each scale has a ivhite streak 

 along its outer margin, as in Ahcetulla irregularis; the lower 

 parts uniform whitish. Some very faint traces of ornamental 

 markings on the head are still visible. 



I consider a specimen from Demerara, 15 inches long (tail 

 3^ inches), as the young of this species, although it is differently 

 coloured. The head has nearly the same markings as a young 

 X. rhabdocephalus. Trunk with seventeen broad brown cross 

 bands, each with a black-and-white edge ; these bands are much 

 contracted in the middle of the back, and the three anterior are 

 entirely severed, forming three pairs of semicircular lateral spots ; 

 lower parts with scattered brown dots. 



Xenodon Neuwiedii. PI. V. fig. C. 

 Head but slightly depressed, rather broad behind, with the 

 snout of moderate length ; trunk not very stout. Eye of mo- 

 derate size. Rostral shield broader than high, just reaching the 

 upper surface of the snout ; vertical longer than broad, scarcely 

 shorter than the occipital ; loreal rather higher than long ; one 

 prseocular reaching to the upper surface of the head ; two post- 

 oculars ; eight upper labials, the fourth and fifth entering the 

 orbit; temporals 1 + 2. Scales in twenty-one series, those of 

 the vertebral line not larger than the others, those on the sides 

 much narrower than the outer ones ; most of the scales have a 

 very indistinct single apical groove. Ventrals 163-174; anal 

 bifid; subcaudals 56-67. Greenish or brownish olive, with 

 twenty or more very broad brown cross bands on the trunk, 

 each being about four times as broad as the interspaces. A more 

 or less distinct brownish band across the snout, and another 



