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Show 66 REPTlLIA. All these venomous speci· es, wh ose mode of pro. duction is we 11 k nown, bri'ng "llo rth living young • ones,• as their egg•s da re hatched without being laid, from which Circu~stance ~s. e-rived their common name of Vipers, a contractiOn of VIVIpa-ro~~ nomous serpents with insulated fangs have externa~ cha- racters very s.u m.1 a r t o those of the preceding ones, but 1n the reater number the jaws are very dilatable, a~d the ton~ue gv ery extensi'b l e. The posterior po. rtion of their · hhe a·d bemg broad, generally gives th_em a. f~rociOus aspect, whic IS a par~ tial indication of their dispositiOn. They form t~o great ge CROTALUS and V IPERA, the second of wluch has been nera, h' h variously subdivided, and some smaller ones w IC group around them. CROTALus, Lin.(l) Rattlesnakes are pre-eminently conspicuous for the intensity of the·t r venom. A s m· Boa ' there are transverse simple plates .u nder the body and tail; but their most distinguishing character 1s the rattle which terminates the tail. It is formed by several scaly cor-t loosely fitted into each other, wkich move and produce the pe-nceu lsia r noise from which they receive the.i r name w h enever they crawl or shake that part of the body. The number of these cornets increase with age, an additional one being always found after each moult. There is a little round indentation or pit beh.ind each nostril.( 2) All the species whose habitat is well ~scertamed are f~om America. The danger resulting from the bite of these noxious reptiles is in proportion to the warmth of the climate or of the sea· son. their natural disposition, however, is tranquil, and they are ra· the; slow and heavy in their motions, never biting unless provoked, or to kill the prey on which they feed. Although the Rattlesnake never ascends trees, its principal foo.d consists of birds, squirrels, &c. It has long been supposed that It possesses the faculty of rendering them pow~rless by its breath, or even of charming them, as it is called, by wh1ch they are com~ell~d to leap into its mouth; this, however, is not so, and the reptile m (1) Crotalus, from "p6rrtJ.?..OV. (2) See Russel and Home, Phil. Trans. 1804, pl. iii, p. 76. OPHIDIA. 67 question seizes its prey while under the agitation and te1·ror produced by its appearance. ( 1) In most of the species there are scales on the head sin; ilar to those on the back. Grot. horridus, L.; Catesb. II, xli, is the species most common in the United States; brown, with irl'egular blackish transverse bands. That of Guiana, Grot. durissus,(2) Lucep. II, xiii, 2, has lozenge shaped spots edged with black, and four black lines along the top of the neck; both species are equally to be dreaded, as death speedily follows a wound from their fangs. They are sometimes found six feet in length. The head of some species is furnished with large plates.( 3) We should approximate to the Rattlesnakes the TRIGONOOEPllALus, Oppel.-BoTHROPs, SPix,-CoPHIAs, Merr. Distinguished ·from them by the want of a rattle, but having the same pits behind the nostrils, and being equally venomous. The sub-caudal plates in some of them are simple, as in the Rattlesnake, their head being covered with plates to behind the eyes; their tail terminates in a small horny spur. ( 4) Such is Golub. tisiphone, Shaw; Catesb. II, xliii and xliv. Brown, clouded with spots of deeper bl'own. In others the sub-caudal scales are double, and the head is covered with scales similar to those on the back.( 5) Such among others is Trig. lanceolatus, Opp. ;( 6) Serpent jaune des .!lntilles, Lacep. II, v. 1. (The Lance-headed Viper.) The most dange•·ous (1) See Barton, Memoir on the power of fascination attributed, &c. Philad. 1796. (2) These names of durissus and horridus have been variously applied to these two species. (3) It is this subdivision which furnished M. Gray with his genus CRoTALOPHO· Rus, and M. Fitzinger with that of Caudisona. The Crot. miliaria, L. Catesb. II, Ilii, belongs to it. N.ll. The C. lwrridus or the Diamond Rattlesnake, the C. durissus or the Banded Rattlesnake, and the C. miliaria or the Ground Rattlesnake, a smaller species, but the most dangerous of the three, all inhabit the United States. The most com· mon is the durissus; the miliaris, although furnished like the others with an apparatus of three or four cornets at the end of the tail, can make no noise with them. The plates on the head are arranged as in the genus Coluber. .11m. Ed. (4) They are the TisiPHONE of Fitzinger. (5) In the work of M. l~itzinger this division is called CRASPEDOCEPHALus; all the BoTnRoPs, Spix, pl. xix-xxiii, belong to it . . (6) This species inhabits Brazil, and most probably oth~ parts of South AmerIca; I am even inclined to think it is the Souroucau of Spix, pl. xxiii, wqich he eonsiders the Crot. mutua or lachuie. \ |