418 [October, 



The transverse bars are frequently broken up, particularly in front, and the 

 larger portions form perfect chevrons. 



The young are yellowish, with irregular dusky marks on the back and sides, 

 the larger ones being transverse ; none of them, however, are serrate, as in the 

 older animals ; instead of a rattle there is a small button at the end of the tail. 



Grows to the length of 8 feet ; one of this size had 9 rattles, whilst another of 

 5 feet had 14. Specimens of the rattles of these snakes have been shown con- 

 sisting of thirty joints ; these are fictitious, and made by taking the separate 

 " grelots" from different rattles and joining them together, for they may be fitted 

 in su'h a manner that the deception cannot be perceived. Had 1 not seen this 

 artificial junction made in my presence, I should have considered these long 

 " crepitacula" as really natural. 



The oak ridge rattle snake. 



Supra niger vel fuscus, serie dorsal i regular! rhomboidum magnorum, concate- 

 natorum, limbo albo, disco fusco, variegato ; subtus flavescens, nigro variegatus 

 et maculatus. 



Hab. In provinciis australioribus Caudisona terrifica Laurenti, p. 93. Cro- 

 talus rhombifer Daudin, vol. v. p. 325. Id. Latreille, vol. iii. p. 197. C. ada- 

 manteus, Palisot de Beauvois, Trans. Am. Phil. Soc, vol. iv. p. 368. Id. Hol- 

 brook, vol. iii. p. 17. C durissus Pennant, Arct. Zool.Suppl., p. 90. Id. Shaw, 

 vol. iii. p. 333, who confounds it with the C. durissus ; of both species furnish- 

 ing very good figures. Lacepede, vol. ii. p. 396. 



Above black or brown, with a row of large black or dusky rhomboidal spots 

 on the back, which on the limb or margin are whitish or yellowish, and on the 

 disc mixed with brown ; these rhomboids are connected together, so that the 

 animal appears to have two yellowish lines running down the back and mutually 

 crossing each other from right to left at certain intervals ; they gradually become 

 less distinct towards the tail until they vanish, some of the posterior ones 

 changing into transverse bands. The sides of those which are brown are marked 

 with two rows of dusky spots ; those which are black, of course, must want these 

 SDots. Tail with alternate bars of black and yellowish, or black and dusky. 

 Body beneath yellowish, mixed and spotted with dusky. Head very large, spot- 

 ted with paler, with two yellowish and three black or dusky stripe.s on each side, 

 sometimes entirely black, the top covered with small scales resembling coarse 

 shagreen. Rostral plate pen! angular, wider and rounded at the base; supernasal 

 plates two, small, a larger quadrangular space between the rostral and nasal ; 

 Ijehind the rostral is a large plate on each side, immediately behind these are 

 two others ; the palpebras are large, transversely striate ; antocular plate large. 

 Abdominal scuta 170 to 178 ; subcaudal 23 to 32, and 4 pair of scales at the base 

 of the rattle. 



Length 6 feet with 6 rattles. 



I come now to the conclusions which are to be drawn from the preceding re- 

 marks - and first, the so-called horridus,\\\e Boiquira and Cascarella of many 

 authors, is the durissus of Linnaeus. I place little reliance on references to en- 

 graved figures, as in many instances they are made in a very careless manner. 

 Thus,we find Linnceus quoting a figure in Seba's Museum, which does not tally with 

 descriptions of other authors quoted by himself; and Laurenti, an author in other 

 respects very cautious and accurate, refers to a figure in Catesby, of a serpent 

 with transverse bars, as representing one with rhombic spots. We are driven^^^ 

 it appears to me, into this dilemma: either the name o{ horridns must be stricken 

 out from acknowledged species, or given to that one' which is called by so many 

 durissus, or, we must call this last one horridus, and thus have the species with 

 two distinct names. For, as I have observed elsewhere, there can be no doubt 

 of the animal, so well described by both Liunoeus and Laurenti, beins^ durissus. 

 Secondly, as for the other species, which Palisot de Beauvois called adamanteus, 

 and which others have named rhomUfer, &c., whether it was known to Linnaeus 

 cannot now be proven, although, for my own part, I have no doubt but that he 

 confounded it with the South American species, or it may be the dryinas which 

 had lost its color. See Amanitatis Academicae, vol. i. p. 501, where he says 



