YENEMOTJS SNAKES. 45 



with numerous teeth, wHch are lengthened, conical, thin and 

 pointed like a needle, and more or less bent backwards. 



In Dr. Giinther's first sub-order, that of Non-venemous Snakes, 

 the teeth are either entirely smooth, or only the last of the 

 maxillary series is provided with a faint longitudinal groove, 

 which is not intended to convey a virus into the wound, the 

 groove appearing rather to increase the strength of the tooth. 

 Many of them have long teeth in front of the jaws or of the palate, 

 but these are never grooved or perforated, and only serve to afford 

 a firmer hold on the living and struggling prey. 



" The structure of the venom-tooth is not the same in all 

 poisonous Snakes : in some it is fixed to the maxillary bone, which 

 is as long or nearly as long as in the non-venemous Snakes, and gene- 

 rally bears one or more ordinary teeth on its hinder portion. The 

 venom-tooth is fixed more or less erect, not very long, and its 

 channel is generally visible as an external groove. The poisonous 

 Snakes with such a dentition have externally a more or less 

 striking resemblance to the non-venemous Serpents, and on this 

 account they are designated as Venemous Colubrine Snakes, form- 

 ing our second sub-order." Two very distinct families are here 

 brought together — viz. the Elapidce (which comprises the Cobras 

 and many others), and the Hydropkidce (or Sea Snakes). 



" In the other venemous Snakes, composing the third sub-order, 

 the maxillary bone is extremely short, and does not bear any 

 teeth except an exceedingly long fang, with a perfectly closed 

 externally invisible channel in its interior. Although this tooth 

 also is fixed to the bone, the bone itself is very mobile, so that the 

 tooth, which is laid backwards when at rest, can be erected the 

 moment the animal prepares to strike. This tooth or fang, like 

 all the other teeth, is not only occasionally lost, but appears to be 

 shed at regular intervals. From two to four other venom-fangs 

 in different stages of development, destined to replace the one in 

 action, exist between the folds of the gum, and are not anchylosed 

 to the bone." The more characteristic venemous Snakes apper- 

 tain to this sub-order— viz. the two families Crotalidm (compre- 

 hending the Eattlesnakes, the Fer-de-lance, &c.) and Viperidce 

 (comprising the Vipers, Pufl'-adders, &c.). 



Let it be particularly borne in mind that the supposed distin- 



