372 LOWER VERTEBRATES. 



feeds on insects, such as grasshoppers and crickets. Helicops, though a tropical 

 genus, is represented in Florida by Allen's JIeKco2}s, a form which, because of the 

 peculiar structure of the tail, stands well up, and perhaps should lead the genus. 

 Abastor ei-ythrogrammus, the so-called hoop-snake, though it possesses none of the 

 remarkable qualities attributed to this monster of tradition, is an abundant species in 

 the south. Though preferring damp and marshy ground, it never voluntarily takes to 

 the water. Farancia abacura, inhabiting the south from the Carolinas to Texas, is a 

 closely related form, though it is more sliy and, consequently, ajsparently less abundant. 

 It lacks the longitudinal dorsal ornamentation, and below is of a deep red color. It is 

 called horn-snake by the negroes. 



The family of desert-snakes, Psammophidje, are chiefly inhabitants of tropical 

 Africa, and are not very well known. In some points of structure they resemble the 

 Dryophidse, though members of this latter family can always be distinguished by 

 their green coloration, and by their horizontally placed pupil : the desert-snakes are, 

 moreover, provided with a pair of long maxillary teeth. Psammophis eleyans is long 

 and slender, though the other members of the family are stout, and adajited for a 

 terrestrial life. P. pidoerulentus is a most repulsive reptile; its undefined ornamenta- 

 tion, swollen lips, and large, hidden fangs, give to it, on examination, a most venomous 

 aspect. It is a small species, inliabiting southern Asia, and the neighboring islands. 

 Ccelopieltis lacertina inhabits Egypt. 



The HoMALOPsiD^ includes fresh-water snakes, which sometimes swim down the 

 rivers to the sea, and in general structure resemble the truly marine snakes, Hydrophi- 

 dae, with which they have sometimes been classified. They have the nostrils so placed 

 upon the tip of the snout as to enable them to breatlie without protruding but a small 

 portion of the head from the water. They prey on fisli and crustaceans, often lying 

 in wait, their prehensile tails being entwined around some submerged branch ; in cap- 

 tivity, however, they generally refuse all nourishment and soon die, otherwise they 

 would make extremely interesting pets, being gentle and harmless. It is stated that 

 the act of parturition is performed in the water, the known species being viviparous. 

 The most interesting form is Herpeton tentaculatum, a species which, though often 

 figured, is extremely rare, a single specimen having been unique for more than half a 

 century, and now the species is only rarely seen in herpetological collections. It 

 inhabits the southeastern portion of Asia, where it is occasionally found in muddy 

 water, its tentacles serving as organs of touch. These rostral appendages are as long 

 as the snout, and are covered with scales similar to those of the loreal region. 



Hypsirkina is characterized by its smooth scales and united frontal plates. The 

 species, about six in number, are restricted in their distribution to the East Indies. 

 Cantor gives an interesting description of a specimen of // enhydris, which he suc- 

 ceeded in keeping for a considerable time in captivity. " Members of this species may 

 be seen in rivers as well as in irrigated fields and estuaries, jn-eying upon fishes, which, 

 however, it refuses in a state of captivity. It is of timid and peaceful habits. A 

 large female, after having been confined upwards of six months in a glass vessel filled 

 Avith water, brought forth eleven young ones. Shortly after the parturition she ex- 

 pired, under a few spasmodic movements; and also two of the young ones died in the 

 course of about two hours, after having, like the rest, shed the integuments. In 

 length they varied from six inches to six and two eighths. The living nine presented a 

 most singular appearance ; they remained a little way below the surface of the water, 

 coiling themselves round the body of an adult male which was also kept in the vessel, 



