156 
REPTILES. OPHIDIA. 
Natkix. 
135. On the character derived from the number of scales either of the belly 
or tail, no reliance can be placed ; so variable are they on individuals of the 
same species. 
Gen. III. NATRIX. Snake. — Destitute of poison-fangs. 
Four regular rows of imperforate teeth above, and two be- 
low. 
3. N. torquata. Ringed Snake. — Head with nine large scales ; 
dorsal scales oval, with a mesial ridge. 
Hydrus, Sihb. Scot. 28 — Nat. torq. Ray^ Syn. Quad. 334 — Coluber Ma- 
trix, Linn. Syst. i. 380. Penn. Brit. Zoo\. iii. 33 — Collared Viper, 
Lac. Ov. Quad. iii. 346 -B, Common Snake; 5', Water Snake ; IV, 
Neidr fraith, Neidr y tome nydd. — Common in England ; rare in Scot- 
land. 
Length from 3 to 4 feet. Back dusky-brown, with two black stripes of 
spots running the whole length, crossed by numerous irregular spots. Belly 
dusky, with a bluish tinge ; a spot of yellow, and another triangular one of 
black on each side the neck. Head depressed ; muzzle rounded ; the large 
scales in four rows, the first and second of two each ; the third of three, and 
the fourth of two ; seventeen scales on each jaw. Scales of the sides small 
and smooth. Belly variegated black, white, and bluish ; the plates of the belly 
about 120 ; pairs of the tail 53, or even 60. Eggs 18 to 20, deposited in dung- 
hills or hot-beds. Feeds on ants, frogs, and mice. Becomes torpid during 
the winter. Easily tamed. Frequents marshy places, and enters the water 
occasionally. 
4. N. Dunifrisiensis. Dumfries-sbire Snake. — Dorsal scales 
destitute of a mesial crest. 
Coluber Dum. Sower. Brit. Misc. tab. iii. 
“ Plates on the belly., 162. Scales under the tail about 80. This coluber seems 
to be entirely new, and was discovered by T. W. Simmons, near Dumfries. As 
only one specimen has been seen, we cannot say much with regard to its usual 
size. 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 zig-zag ; with intervening spots on the side.” This 
is 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 are 
represented in the figure, and intimate that this cannot be the young of the 
common viper ; while the smooth dorsal scales indicate that it is a distinct 
species from the ringed snake. In the last character, it agrees with the smooth 
viper. Col. Austriacus of Gmelin, a species common in (Germany and France, 
of which it may probably be only a variety. 
Gen. IV. VIPERA. Viper, — Maxillary bones with poison- 
fangs, but no common teetb. Scales behind tbe vent di- 
vided. Neck narrow. Head destitute of plates. 
5. V. communis Common Viper or Adder.— Dorsal scales 
oval, carinated ; inferior lateral ones subangular and plain. 
