SYNOPSES AND DESCRIPTIONS. 117 



CrOTALUS LEPIDUS. 

 Caudisona lepida Kenn., 1861, Pr. Ac. X. Sc., PM., 206. 



"Head ovoid, tapering to the nose, which is very narrow, pointed, and 

 much depressed. Nostril very small, circular, and placed near the point of 

 the nose in about the middle of a single nasal. Two elongated frontals 

 (internasals) in contact, extending behind the nostrils. Supraciliaries and 

 other large plates smooth. Rostral subtriangular, broader than high, the 

 apex turned back slightly upon the crown. Upper preorbital small, and 

 separated from the postnasal by the width of two larger plates. Labials 

 rather large, 12 above, 10 — 12 below. Color of head yellowish ash." 



"By the smoothness and size of the plates and absence of the horn, it 

 will at once be distinguished from C. cerastes." Two heads from Presidio 

 del Morte and Eagle Pass were described. Species of doubtful position. 



CROTALUS TIGRIS. 

 (Kenn.) Baird, 1858, U. S. and Mex. Bound. Survey Rept., 14, pi. IV. 



Slender; head small, depressed. Supraciliaries and frontals smooth. 

 Four frontals, six postfrontals (does this mean a pair of internasals, a pair 

 of prefrontals and dissected frontal and parietals?) Two rows of scales 

 between suborbitals and labials. Labials 14 above, 13 — 14 below. Series 

 of scales 21 — 23, very slightly carinated. 



Color yellowish ash above, with rather small, indistinct dorsal brown 

 blotches anteriorly; two posterior thirds of body banded with brown. 

 (Kennicott.) Deserts of Gila and Colorado. 



Two internasals. Two prefrontals. Two shields between the supracil- 

 iaries, separated somewhat in front by a triangular shield; behind these 

 irregular scales or small shields. Labials 10, a small shield separating the 

 fourth and fifth from the eye. Series of scales 21. Ventrals 1604-21. 



Brownish, with seven series of spots, median larger, confluent posteriorly. 

 A dark band from the lower border of the orbit above the angle of the 

 mouth. (C. intermedius.) Mexico. 



Crotalus triseriatus. 



Wagler, 1830, Syst. Amph., 176. 



A pair of internasals. Four or more prefrontals. Frontal region covered 

 with scales or small polygonal plates. Labials 12 — 14. One to two scales 



