History of British animals - University of Guam Marine Laboratory

156 REPTILES. OPHIDIA. Natrix.135. On the character derived from the number of scales either of the bellyor tail, no reliance can be placed ; so variable are they on individuals of thesame species.Gen. III. NATRIX. Snake.— Destitute of poison-fangs.Four regular rows of imperforateteeth above, and two below.3. N. torquata. Ringed Snake. — Head with nine largescales ;Neidr fraith, Neidr y tome nydd.—Common in England ;dorsal scales oval, with a mesial ridge.Hydrus, Sibb. Scot. 28 Nat. torq. Ray, Syn. Quad. 334—Coluber Natrix,Linn. Syst. i. 380. Perm. Brit. Zool. iii. 33—Collared Viper,Lac. Ov. Quad. iii. 34G E, Common Snake ; S, Water Snake ; W,rare in Scotland.Length from 3 to 4 feet. Back dusky-brown, with two black stripes ofspots running the whole length, crossed by numerous irregular spots. Bellydusky, with a bluish tinge; a spot of yellow, and another triangular one ofblack on each side the neck. Head depressed ;muzzle rounded ; the largescales in four rows, the first and second of two each ; the third of three, andthe fourth of two ; seventeen scales on each jaw. Scales of the sides smalland smooth. Belly variegated black, white, and bluish ; the plates of the bellyabout 120 ;pairs of the tail 53, or even CO. Eggs 18 to 20, deposited in dunghillsor hot-beds. Feeds on ants, frogs, and mice. Becomes torpid duringthe winter. Easily tamed. Frequents marshy places, and enters the wateroccasionally.4. N. Diimfrisiensis. Dumfries-shire Snake.— Dorsal scalesdestitute of a mesial crest.Coluber Dum. Sower. Brit. Misc. tab. iii." Plates on the belly, 1 62. Scales under the tail about 80. This coluber seemsto be entirely new, and was discovered by T. W. Simmons, near Dumfries. Asonly one specimen has been seen, we cannot say much with regard to its usualsize. The figures are pretty accurately drawn, as to the size of the specimen(about 5 inches). The scales of the back are extremely simple, not carinated.It is of a pale colour, with pairs of reddish-brown stripes from side to side,over the back, somewhat zigzag; with intervening spots on the side." Thisis all the information which has yet been acquired concerning this species.There is no mention made of the large scales on the head, though they arerepresented in the figure, and intimate that this cannot be the young of thecommon viper; while the smooth dorsal scales indicate that it is a distinctspecies from the ringed snake. In the last character, it agrees with the smoothviper, Col. Austriacus of Gmelin, a species common in Germany and France,of which it may probably be only a variety.Gen. IV. VIPER A. Viper.— Maxillary bones with poisonfansrs,btit no common teeth. Scales behind the vent divided.Neck narrow. Head destitute of plates.5. V. communis Common Viperor Adder.— Dorsal scalesoval, carinated ; inferior lateral ones suhangular and plain.