358 REPORT OF NATIONAL MUSEUM, 1893. 



The difference is well whovvii in the accoinpiiiiyiug figures, wliicli also 

 bring out several of the structural characters referred to above.* 



A formal though condensed account of the natural hisloiy of the 

 ElKpidw occurring within the United States is here presented. 



(ienus ELAl'S.t Schneider. 



The Coi;ai, Snakks. 



1801. — Flaps, ScHNKiOKR, Hi.st. Ain]ihili.. ii (]>. 289).— Gi'NTHKK. Proc Zoo]. 

 Soc, Loud., IS.'J;!, ]). 84. 



Postfrontal bone wanting; internasal plate not reaching labials; two 

 nasals; no loreal; subcaudal shields (urostcges) divi<led; eyes very 

 small, pupil a short vertical ellipsoid. 



The snakes of this genus are cylindrical, rather elongate, but with 

 short tail, and characterized by bright colors of red, black, and often 

 yellow, forming rings. In many of the exotic species the black rings 

 are arranged in threes, while in the North American species those of 

 the body are equidistant. The scales are smooth and iridescent. 



The exact number of species can not be given at present on account of 

 the uncertainty of the status of many of the described forms, but at 

 least twenty inhabit the New World, of which only two occur north of 

 Mexico. 



While the poison apparatus of the rattlesnakes and their nearest 

 relations has been studied very minutely, that of the genus Elaps has 

 been sadly neglected, as has been, in fact, its entire anatomy. Drs. 

 Matthes and Voigthiender have given short and superficial accounts 

 of U 1(12)8 fulvius, from which i I make a few abstracts: The functional 

 fang in Elaps fulvius is followed by reserve fangs of the same struc- 

 ture as the functional one, but successively smaller. The functional 

 fang is solidly united to the maxillary bone, being directed backward 

 at a permanent angle of about 45° with the latter. Although com- 

 paratively smaller than the fangs in the crotalid snakes, that of Elaps 

 is large enough to distinguish it at the first glance as dilicrent from 

 the solid teeth of the palate and of the lower jaws. In front, at the 

 base of the fang, tlie opening of the canal is distincly visible, and on 

 the convex, or anterior, surface of the fang a shallow groove. The 

 terminal slit, being the lower opening of the canal, is situated slightly 

 on the outer side of the fang. 



As already stated there are found in the United States only two well 

 defined species of Elaps, but these are so sharply defined that they may 

 be told apart at a glance, by the following characters: 



* The brilliant colors of all these snakes fade soon in alcohol ; the red becomes j-ray- 

 ish or light brownish ; the yellow grows pale, often ((uite white j and the deep black , 

 often bluish, turns a dull brown. 



t From iAatp (elaps), a Greek name for a snake. 



t Denkschr. Naturw. Gesell. Isis, 1860, j))!. 52-59, and p. 64. 



