350 



REPORT OF NATIONAL MUSEUM, 1893. 



'Fig. 1. 



DIAGRAMMATIC LATERAL 



VIEW OF THE HEAD OF 

 TRAUOPS. 



a Poison gland; b supra- 

 labial gland. 



(After Niemann.) 



true supralabial glaud, although both glands are eontaiued in the same 

 envelope of connective tissue, and he was able to trace the single duct 

 leading from the yellowish gland to the groove of the posterior elon- 

 gated fang. One of the species was Tragops prasinns, Wagler (the same 

 species with which Prof. Vaillaut experimented), and an inhabitant of 

 the East Indies, the other heiug Lepiodeira anun- 

 lata, (L.), from tropical America. Fig. 1 is a copy 

 of Mr. Niemann's schematic representation of the 

 arrangement in the former. Fig. 2 shows a sec- 

 tion of the grooved fang near its base, copied from 

 the same author. 



That, these snakes are not entirely harmless, 

 even to man, is evident from the very recent expe- 

 rience of Mr. J. J. Quelch, of Georgetown, British 

 Guiana,* who was bitten on the first finger by a large specimen of the 

 common red-white-andblack-banded snake, Eryihrolamprns venustlssi- 

 mus, driving its hinder grooved teeth three times- down into the flesh. 

 About half an hour after, the linger became much swollen at the place 

 and distinctly very painful. It was not till about four hours after- 

 ward that real relief was obtained, though the place 

 was tender for a much longer time. Another case 

 was that of the clerk in the Museum, who was bitten 

 on the finger by a young specimen of the. common 

 frog snake or Mattipi, Xenodon sererus, whose binder 

 enlarged teeth were driven deeply into the flesli, with 

 a result similar to that described in the case of the 

 other snake. 



It will be observed that while the snake by which 

 Mr. Quelch himself was bitten is a true opistoglyph 

 with grooved posterior fangs, the. one which caused 

 a similar result in the clerk, viz, the Xenodon, has 

 the enlarged posterior teeth solid and not grooved. 

 I would call attenti(m to the fact, however, that this 

 identical species is described by Duvernoyt as iiaving the yellowish 

 gland well differentiated. That the bite of the allied species, Xenodon 

 rliabdoceplwlus, did apparently have no unpleasant effect on Dr. Strad- 

 liiigl is not difficult of explanation in view of the fact that occasionally 

 the bite of even some of the most dangerous snakes has been ineffective, 

 but enough is said to show that the question is not an unreasonable one: 

 Is it essential for a truly venomous snake to possess grooved fangs? 



As a matter of fact, at the very moment of this sentence going to 

 press, the (piestion seems answered conclusively in the negative by the 

 experiments of Phisalix and Bertrand, who have shown that the saliva 



Fig. 2. 



CROSS ■ SECTION OF 



GROOVED FANG OF 

 TRAGOPS PRASINUS, 

 NEAR BASE. 



Enlarged, a I'oiaon 

 groove; 6 pulp t-avity. 



I .^fter Kiennnn. ) 



* Zooloiiist (3), XVII, .January, 1893, pp. 30-31. 



t Ann. 8c. Nat., xxx, 1833, pp. 14-15. 



X Referred to in Miss C. C. Hopley's, "Snakes, etc." 1882, p. 400. 



