354 LOWER VERTEBRATES. 



and kill full-grown men by their powerful coils, though those reptiles are ordinarily 

 of a most timid nature, retreating on the least disturbance. The variations in -form 

 presented by the sub-order have their extremes in the short thick body of the Tortri- 

 cidse, or the bluntly terminated body of Silybitra, and the slender elongated form pre- 

 sented by many of the Uendrophidse. A few, such as the pythons and boas, and 

 some of the Erycidse, as well as the Tortricidse, have the pelvic limbs represented by a 

 pair of anal claws. 



The first to be treated, and, consequently, the lowest family of colubrifoiTU snakes, 

 includes a number of Asiatic underground forms, having many characters in common 

 with the Typhlopidse, united under the name Ukopeltid^, or shield-tails. The mem- 

 bers of this family have the cylindrical body passing without any visible constriction 

 into the short pointed head. The tail is abbreviated and often terminates abruptly 

 in a naked disc, or, in the genus Silybura, covered with keeled scales. The eyes are 

 very small, and the cleft of the mouth of inconsiderable width, and not distensible ; 

 the jaws are armed with but a small number of teeth. The shield-tails, it will thus be 

 seen, are adapted for an underground life, where they find larvise, worms, and ants' 

 eggs, of which latter they are very fond. Though seldom met with, they are very 

 abundant in numbers, and chiefly inhabit the island of Ceylon, though some forms are 

 found on the neighboring mainland. The genus Hhinophis includes several Cin- 

 ghalese species, characterized by having the nasal plates separated by the rostral ; 

 and the tail, which is shorter in the female, covered by smooth scales, and terminated by 

 a rough shield. M. oxyrhynchus reaches a length of fifteen inches, and is found in the 

 loam at a depth of two or three feet, as well as in ant-hills. R. punctatus, which 

 attains the length of nineteen inches, is the largest species. 



Of the genus ZTropeltis, only a single species, U. gixmdis, the largest of the family, 

 is known. It inhabits the mountains of Ceylon and is exti'emely rare. The genus 

 Silybura includes a number of species which have the scales of the abrupt tail 

 strongly keeled, and the supra^orbital and postocular shields confluent. S. macrolepis 

 is represented by a single Indian specimen measuring ten inches in length. Plecturus 

 has only two uninteresting forms. The final genus of the Uropeltidse contains but a 

 single species, Melanophidium wynaadense, which has the termination of the tail 

 armed with a rough horny point. The genus and species have been described from a 

 specimen captured at Wynaad at an elevation of 3,500 feet. 



The second family, ToKTKiniD^, or short-tails, have the short, blunt head depressed, 

 and not distinctly marked off from the body, which is protected by evenly laid, 

 smooth plates, those of the ventral side exceeding the others but little in size. The 

 eyes are small; the labials but six in number; and the teeth are few but stout. The 

 most noteworthy feature, however, is the rudimentary pelvis, which bears a pair of 

 small limbs which make their appearance each side of the base of the tail as 

 small claws. Members of this family are found in both hemispheres, where they pre- 

 fer the dry and sandy districts, burrowing near the surface for subterranean worms 

 and insects. Tortrix scytale is beautifully banded with black, and does not exceed two 

 feet in length. Its habitat is the valley of the Amazon, the natives often wearing it 

 as an animated neck-ornament. T. eryx inhabits southern Europe and Egypt. The 

 genus Cylindrophis is characterized by the absence of intermaxillary teeth. But three 

 species are known, two of which inhabit British India, where, being, like the other 

 members of the family, sub-terrestrial, they are seldom found. 



To the family Tortricida3 may be appended the genus Xenopeltis, to which some 



