COLUBER PORPHYEACEUS. 239 



each with a yellow centre and a narrow yellow margin; irregular black spots along the 

 sides. Head with black cross bands : one across the anterior frontals and the first upper and 

 second lower labials ; a second runs across the fronto-vertical suture, and passes through the 

 eye to the lower jaw ; the third is V-like, and occupies the crown of the head ; another 

 black spot on the suture between the fifth and sixth upper labials ; belly with numerous 

 black cross bands, generally interrupted in the middle. 



This beautiful species is an inhabitant of the island of Chusan; the largest specimen I 

 ive seen is 2 J 

 on Plate XX. 



have seen is 28 inches long, the tail measuring 5 inches. Three views of the head are given 



Coluber porphtraceus. (Plate XX. fig. I.) 



Coluber porphyraceus, Cantor, Proc. Zool. Soc. 1839, p. 51. 



Psammophis nigrofasciatus, Cantor, I.e. p. 53 (young). 



CoroneUa callicephalus, Gray, Ann. ^ Mag. Nat. Hist. 1853, xii. p. 390. Bhjth, Journ. As. Soc. 



Beng. xxiii. 1855, p. 289. 

 Coluber caUicephalus, Gilnth. Colubr. Snakes, p. 92. 



Body and tail of moderate length ; head narrow, oblong, scarcely distinct from neck ; 

 snout rather long. Rostral as broad as high; anterior frontal truncated in front, rather 

 broader than long, its anterior margin being shorter than its posterior. Vertical very large, 

 rather longer than broad, six-sided, with an obtuse angle in front and a right angle behind, 

 and with the lateral margins convergent ; occipitals considerably longer than broad, obliquely 

 truncated behind. Loreal rather longer than high ; one prseorbital, extending on to the upper 

 surface of the head, in contact with the vertical ; two small postorbitals ; temporals elongate, 

 1+2, the anterior in contact with the lower ocular only. Eight upper labials, the fourth 

 and fifth entering the orbit. The anterior chin-shields in contact -ndth four lower labials. 

 Scales smooth, without apical groove, in nineteen series. Ventrals scarcely extending upwards 

 on the sides, 189-211 ; anal bifid ; subcaudals 56-70. Each maxillary is armed with sixteen 

 teeth equal in size. Brownish olive above, with about twenty-two very broad, darker, black- 

 edged cross bands ; a narrow black streak commences behind the middle of the trunk, and 

 runs along each side of the back to the tip of the tail. Crown of the head with a black 

 median longitudinal streak ; a second runs from behind the orbit to the first cross band. 

 Belly uniform whitish. In the young the cross bands are entirely black, edged with white, 

 reaching downwards to the belly. 



This very fine species appears to be confined to Khasya and Assam ; our largest specimen 

 is 29 inches long, the tail measuring 5^ inches. Two views of the head are given on 

 Plate XX. 



I have examined a coloured drawing of Cantor's Coluber porphyraceus, and the typical 

 specimen of his Psammophis nigrofasciatus. both being preserved in the Museum of the 

 University of Oxford. 



