VIPERA.] REPTILIA OPHIDIA. 297 



reous brown, tinged with green : at the back of the head a double lunulate 

 spot, of a bright yellow colour, behind which is a double one of black, 

 larger and more triangular: two rows of small black spots disposed longi- 

 tudinally down the middle of the back, besides which are some larger 

 ones on the sides, uniting to form short transverse undulating bars : 

 throat, and beneath the neck, yellowish white ; abdomen, and under sur- 

 face of the tail, dusky blue, mottled in some places with yellowish white ; 

 edges of the abdomen with a series of yellowish white spots. 



A common species ; met with in woods and hedges, as well as in 

 marshes. Is particularly abundant in the fens of Cambridgeshire, where 

 it sometimes attains a large size. Often takes to the water, especially 

 when alarmed ; and swims easily : will occasionally remain at the bottom 

 for a considerable time. Feeds on frogs, mice, insects, &c. Is oviparous. 

 Eggs from sixteen to twenty in number, often deposited on dunghills, 

 or under hedges. Hybernates during Winter : reappears in March, or 

 early in April. When irritated, voids a foetid substance. 



(5.) N. Dumfrisiensis, Flem. Brit. An. p. 156. Coluber Dum- 

 frisiensis, Sow. Brit. Misc. p. 5. pi. 3. Loud. Mag. of Nat. 

 Hist. vol. ii. p. 458. (Copied.) 



An obscure species, of which little is known. Said to be particularly 

 characterized by having ' ' the scales of the back extremely simple, not 

 carinated : plates on the belly one hundred and sixty-two : scales under 

 the tail about eighty. Of a pale brown colour, with pairs of reddish 

 brown stripes from side to side, over the back, somewhat zigzag ; with 

 intervening spots on the sides." Sow. Only one specimen known, which 

 was discovered by T. W. Simmons, near Dumfries. According to 

 Sowerby's figure, which is said to be of the natural size, its length does 

 not exceed three or four inches. Probably an immature variety of the 

 common species. 



GEN. 6. VIPERA, Daud. 



7- V. communis, Leach. (Common Viper.) Three 

 plates on the upper part of the head, larger than the 

 surrounding scales ; dorsal scales carinated : a series of 

 confluent rhomboidal black spots down the back. 



V. communis, Leach, Zool. Misc. vol. HI. p. 7. Flem. Brit. An. 



p. 156. Vipera, Ray, Syn. Quad. p. 285. Coluber Berus, Turt. 



Brit. Faun. p. 80. Viper, Penn. Brit. Zool. vol. m. p. 26. pi. 4. 



no. 12. Common Viper, Shaw, Gen. Zool. vol. HI. p. 365. 



pi. 101. 



DIMENS. Length from one and a half to two feej ; rarely more. 

 DESCRIPT. {Form.) Shorter, and, in proportion to its length, thicker, 

 than the Natrix torquata. Head depressed, widening behind the eyes ; 

 neck somewhat contracted; gape as long as the head, slightly ascending 

 posteriorly ; jaws very dilatable ; two rows of fine teeth on the palatines, 

 but none on the maxillaries, besides the poison-fangs: body gradually 

 increasing in thickness to about the middle of the entire length, from 

 that point scarcely diminishing to the vent, beyond which it tapers quite 

 suddenly : tail very short, not one-ninth of the entire length, terminating 

 in a sharp point : upper part of the head covered with small squamous 

 plates, different from the imbricated scales of the back ; of these plates 

 three are larger than the rest, one situate in the middle between the 

 eyes, the two others immediatelv behind the first : dorsal scales imbri- 



