2 72 



TWO NEW SNAKES FROM ASSAM. 



BY 



Major F. Wall, I.M.S., C.M.Z.S. 



(WITH A PLATE.) 



{Read before the Bombay Natural History Society on the 



25th July 1907.) 



Within a month I have had the good fortune to acquire two snakes 

 new to science. 



The first was one of four snakes which had been preserved in spirit 

 some years, and stowed away as rubbish in a godown. My written 

 appeal for snakes in the Dibrugarh Club brought these specimens back 

 to recollection. The habitat is almost certainly Tinsukia. 



Dipsadomorphus guincunciatus. 



This snake is a very typical Dipsadomorphus but differs from all 

 others previously described. The divided anal shield alone will distin- 

 guish it from all the other known Indian species. 



Description. — Rostral : Touches six shields, the sutures made with 

 the anterior nasals being one-fourth longer than those made with the 

 internasals. Tnternasals : Two ; suture between them three- fourths that 

 between the prefrontal fellows ; two-thirds the internaso-prfefrontal 

 suture. Prefrontals : Two ; thn suture between them subequal to the 

 prsefronto-frontal ; in contact with internasal, postnasal, loreal, pne- 

 ocular, supraocular, and frontal. Frontal : Touches six shields, the 

 fronto-supraocular sutures being about one-fourth longer than the rest. 

 Supraoculars : Length equal to breadth ; from half to two-thirds that 

 of the frontal. Nasals : Two subequal shields, touching the 1st and 2nd 

 supralabials. Loreal : One; rather higher than long. Prceocular : One, 

 barely reaching crown. Postoculars : Two. Temporals : Small scale- 

 like; two superposed anteriorly. Supralabials : Eight on the right side, 

 with the 3rd, 4th and 5th touching the eye. Nine on the left side with 

 the 4th, 5th and 6th touching the eye. Posterior sublinguals : Greater 

 than anterior ; in contact with the ftth, 6th and 7th infralabials ; in con- 

 tact with one another in front. Infralabials: The 7th is the largest of the 

 series, is rather broader than the posterior sublinguals, and in contact 

 with 3 scales behind. Costals : Two heads- lengths behind head J 9, 

 mid-body 19, 2 heads-lengths before vent 15. In the step from 19 to 

 17 the uppermost row is absorbed into the vertebral; from 17 to 15 the 



