114 synopses and descriptions. 



Ceotalus confluentus. 



Crotalus confluentus Say, 1823, Long's Exp. II, 48. 



Distinguished from atrox by the subdivision of the head-shields, a greater 

 shortening of the spots in the dorsal series, and the ashy colors. The num- 

 ber of spots and bands is increased. Internasals divided so as. to place 

 small plates between them and the nasals. Loreals two or one — the upper 

 being united with the small prefrontal. A single scale between the anterior 

 suborbital and the labial. Labials 14 — 17. Scales in 25 — 29 rows, outer 

 two or three smooth. Ventrals 178 — 1864-19 — 27, posterior subcaudals 

 bifid or entire. Spots in dorsal series 41 — 54. Young with the white lines 

 very distinct on the head. A lot of specimens from the same locality have 

 the rows of scales in 25, in 27, and in 29 rows. 



Specimen 2455 (Mus. Com]). ZooL), taken near "Ft. Hays, Kansas, by Mr. 

 J. A. Allen, has a supraciliary produced as in C. cerastes, two loreals on one 

 side and one on the other, and 29 rows of scales. C, pyrrhus, I am inclined 

 to think, was founded upon an individual variation. 



CROTALUS LUCIFER. 



Crotalus lucifer Baird & Girard, 1852, Proc. Ac. N. Sc, Phil., 177. 



Spots or rhombs broader than in atrox or confluentus. Colors generally 

 darker. The black band from the eye backward passes above the posterior 

 labials. Nasal and anterior labial frequently separated by small scales. 

 One or two scales between the anterior suborbital and the labials. Loreal 

 one, sometimes two. Internasals subdivided, separated by a row of small 

 scales from the nasals (sometimes from rostral also). Labials 13 — 16. 

 Scales in 25 (25—27?) rows. Ventrals 169—179+19—24, Spots and 

 bands 30—42. Hab. 



Crotalus exsul n. sp. 

 Comparatively slender; neck small; head large, broad behind, outline as 

 seen from above a suboval ; snout short, broad ; tail short. Eye moderately 

 large. Head covered with small imbricate striate scales; a pair of larger 

 ones in contact with the rostral and each other, another pair in contact with 

 the nasals, but separated by a pair of small prefrontals. A larger scale on 

 each side between supraciliary and postnasal. Supraciliaries large, striate. 

 Rostral higher than wide, subtriangular, rather pointed above. Anterior 



