ON THE COMMON INDIAN SNAKES. 54,5 



The Gamma, or Common Brown Tree-Snake. 



( Dipsadomorphus trigonatus.) 



{Dipsas trigonata). 



Nomenclature. — ( a ) Scientific. — The generic name is from the 

 Greek " Dipsas", a species of snake, and " morphe" form, implying a 

 similitude in form to that of the Dipsas. Under the name Dipsas* 

 many snakes were included by the older writers, which modern her- 

 petologists consider separable into many distinct genera. The name 

 is now retained to designate the genus of the original snake to whicb 

 it was applied by Laurenti in 17G8, a South American species, viz., 

 Dipsas. bueephala. The other forms now considered distinct have 

 had to be rechristened, and among them the genus to which the 

 species under discussion belongs. 



The title now retained for it by Mr. Boulenger originated with 

 Fitzinger in 184o, and was applied by him to this species. It is 

 very doubtful, however, whether this name will stand, as the same 

 authority gave the name Boiga to the species irregularis of this 

 genus in 1826 as shown by Stejneger f recently. 



There seems little doubt that the name of the genus will have to 

 be changed to Boiga, but ] refrain from doing so here, as I follow in 

 Mr. Boulenger's footsteps in nomenclature in these papers. 



The specific name trigonatus is from the Greek " tri " three 

 " gonia " angle, and is applied to the peculiar markings on the body, 

 which often very obscure appear to me to much more resemble the 

 Greek letter * than triangles. The name was introduced by 

 Schneider for this species in 1802. 



* This name was evidently borrowed from the ancients who applied it to some snake 

 the identity of which is at the present day probabh not known. It was reputed to be 

 venomous andai-cording to some, one of the effects of its bite was an insatiable thirst (Gr. 

 " Dipsa" thirst), though Lucan makes it appear that it was the creature itself that was 

 afflicte-i with thirst. Thus in his Pharsalia written in the first century A. D. he alludes to 

 it on the occasion when Cato was leading his army across the desert. The passage has been 

 thus translated : 



And now with fiercer heat the desert glows, 



And midday gleanings aggravate their woes, 



When, lo ! a spring amid the sandy plain 



Shows its clear mouth to cheer the fai' ting train. 



But round the guarded bank in thick array 



Dire aspics roll d their congregated way, 



And thirsting in the midst the Oipsas lay. 

 t Proc. Biol. Soc. Washington, XV., 1902 p. 16. 



