OPHIDIA. 67 



question seizes its prey while under the agitation and terror pro- 

 duced by its appearance. (l) 



In most of the species there are scales on the head sin ilar to 

 those on the back. 



Crot. horridiis, L.j Catesb. II, xli, is the species most com- 

 mon in the United States; brown, with irregular blackish trans- 

 verse bands. That of Guiana, Crot. durissus,{2) Lacep. 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 



Trigonocephalus, 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 Rat- 

 tlesnake, their head being covered with plates to behind the eyes; 

 their tail terminates in a small horny spur. (4) Such is 



Colub. tisiphone, Shaw; Catesb. II, xliii and xliv. Brown, 



clouded with spots of deeper brown. 



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 .Antilles, Lacep. 



II, V. 1. (The Lance-headed Viper.) The most dangerous 



(1) See Marion, Memoir on the power of fascination attributed, Sec. Phllad. 1796. 



(2) These names of c^umsMS and /jornc^us have been variously applied to these 

 two species. 



(3) It is this subdivision which fui'nished M. Gray with his g'enus Chotalopho- 

 Rus, and M. Fitzinger with that of Caudisona. The Crot. miliaris, L. Catesb. II, 

 xlii, belongs to it. 



N.U. The C. fiorrtdus or the Diamond Rattlesnake, the C. durissus or the Banded 

 Rattlesnake, and the C. miliaris 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 appa- 

 ratus 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, .im. Ed. 



(4) They ai"e the Tisiphone of Fitzinger. 



(5) In the work of M. Fitzinger this division is called Craspedocephai,us; all 

 the BoTiiHOPS, Spix, pi. xix — xxiii, belong to it. 



(6) This species inhabits Brazil, and most probably other parts of South Amer- 

 ica; I am even inchned to think it is the Souroucou of Spix, pi. xxiii, wliich he 

 considers the Crot. mutus or lachesis. 



