342 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XIV. 



&c. In Amhhjceplmlus the same peculiarity is observed, and it appears 

 to me a family characteristic since all the species I have had access to, 

 elicit it. {li) In some of the genus Lycodon, notably aulicus, &c,, and 

 also in Trachischiu77i the rule is again infringed by the meeting of 

 the loreal with the internasals, and this is of particular importance in differ- 

 entiating between species in the former, 



(2) The loreal. — When a loreal exists, the prtefrontal always comes into 

 contact with it, but it is often absent, and leads to a variety of other relations, 



(3) Labials. — This is an unusual relationship. It may exist with the 

 presence of a loreal as an inconsistent occurrence in some Dryophis. In 

 some snakes where the loreal is absent, the prseErontals effect a contiguity 

 with certain labials, though it is far commoner in these cases to find the 

 pr^ocular meeting the nasals. In Blythia, Calamarla, and Aspklura this 

 feature appears to be of generic importance, and in Uropeltidce and Ilysiidce 

 a family peculiarity. 



(4) Prceoculai\ — When this scale is present, which is usually the case, it 

 always forms a suture with the prsefrontal, 



(5) The eye. — This relationship is most unusual, for, as a rule, the pra30cular 

 by meeting the supra-ocular effectually frustrates such a contingency ; how- 

 ever, sometimes the prsefrontal is permitted to contribute to the circumfer- 

 ence of the orbit. This occurs in some Lycodon, CallopMs hihronii, &c., where 

 it serves to diffeientiate between species, and also in Blythia, Cylindrophi>j, 

 Xylophis, Calamaria, and Aspidura, where it is equally valuable in charac- 

 terising genera, and in Amblycephalus constitutes a family feature. 



Posteriorly, the supra-ocular nearly always meets the posterior part of the 

 prsefrontal, but exceptions occur in Coluber oa'ycepholus, Lycodon aidicus, 

 &c,, of special importance, and in the genus Dryophis where contact 

 with the supra-ocular is denied by the meeting of the prteocular with 

 the frontal and also in Python and Zamenis diadema where a supernumerary 

 row of small scales frustrates the normal arrangement. 



The frontal is nearly always one of the posterior relations of the prte- 

 frontal, but exceptions occur in Python and Zamenis diadema where a 

 supernumerary row of scales prevents such contact. 



The following exampleswill demonstrate some of the numerous variations 

 in relationship this scale is subject to : — 



Calamaria. — Rostral, 1st and 2nd labials, prreoc,, supraoc., frontal, 

 Cylindrophis. — Nasal, 2nd and 3rd labials, eye, supraoc, frontal. 

 Blythia. — Internasal, 2nd and 3rd labials, eye, supraoc,, frontal, 

 Hydrophis. — Nasal, 2nd labial, prasoc,, supraoc,, frontal, 

 Zamenis diadema. — Internasal, nasal, two or three loreals, prseoc, super- 

 numerary prefrontals, 

 Hypsirhina enhydris. — Internasal, loreal, prceoc,, supraoc, frontal. 

 Lycodon aulicus. — Internasal, loreal, prteoc,, frontal. 

 Aspidura. — Internasal, nasal, 2nd and 3rd labials, prseoc, supraoc, 

 frontal. 



