NOTES. 67 



4. Vibration of the Tails of S^iakes — In a recent Note {SpoUa 

 Zeylanica, Vol. VII., Part XXVIII., p. 207) Mr. Abercromby calls 

 attention to the habit of vibrating the tail indulged in by Lachesis 

 trigonocephalus. In this it is not alone, and the action has often 

 been noticed in the case of L. graminens ; amongst recent authors, 

 I think that Gadow calls attention to it in his book on " Mexico," 

 though the volume is not available here to verify the impression. 

 Gunther (Rept. Brit. India, p. 384) also notes that "they are 

 frequently not perceived until they prepare to dart, vibrating 

 the tail and uttering a faint hissing sound." In this connection 

 it is of interest to o'bserve that the snakes of this genus usually 

 have the tail modified in some special way, either brightly 

 coloured or peculiarly shaped. L. gramineus, indeed, derives one of 

 its synonyms {erythrurus) from the colour of its tail, the specimen 

 figured by Fayrer (Thanat. Brit. India, PI. XIV.) belonging to this 

 form, whilst in the case of the American L. mutus the tail terminates 

 in a long, tliin spine, whicli, as Dittmars (Rept. of the World, p. 339) 

 notes, suggests an ancestral relationship to the rattlesnakes. 



It is however a fact, as Mr. Abercromby remarks, that other 

 snakes, in nowise related to the Pit Vipers, share this peculiarity 

 of vibrating the tail. Quite lately my mali brought in a specimen 

 of Dipsadomorphus trigonatus which he had caught whilst clipping a 

 hedge — a, favourite haunt of this species ;. when placed on a bush 

 in a vivarium, the snake struck out valiantly at anything that 

 approached, at the same time vibrating its tail rapidly against a 

 flat leaf and producing quite a sharp rattling noise. A few months 

 ago I noticed the same thing in a specimen of Lycodon aulicus in 

 one of my cages ; when annoyed and on the defensive it repeatedly 

 quivered its tail very rapidly, so as to produce a distinct rattling 

 against the floor of its cage. 



T. BAINBRIGGE FLETCHER. 



5. On " Megaderma lyra." — Mr. Green's colony of Megaderma lyra 

 (see Spolia Zeylanica, Vol. VII., Part XXVIII,, p. 216) is possibly 

 an abnormally blood-thirsty one. Last year I had frequent 

 opportunities of observing this bat, as the bungalow in which I was 

 living had several empty rooms, and the bats used to fly in through 

 the open windows and suspend themselves from punkahs, &c., to 

 eat their prey. It is noteworthy that each bat has what is presum- 

 ably its own favourite perch, to which it brings all its larger prey 

 to eat. Inspection of the remains after the bats had been feeding 

 showed that their food had been almost entirely large Lepidoptera — 

 mostly Sphingids and large Noctuids, amongst which Ophideres 

 fullonica appeared a great favourite ; I saw no remains whatever of 

 any Vertebrates. The bats were quite bold, and often flew around 

 the lamps in the verandah catching moths in the air or from off the 



