SYNOPSES AND DESCRIPTIONS. 118 



Hab. North Carolina to Texas, and through varieties to California and 



Mexico, 



var. SCUTULATUS. 

 Caudisona bcuttoata Kenn., 1861, Pr. Ac. N. Sc, Phil., 207. 



Rattle and rostral plates as in C. heifer. Dorsal rows 25; superior 

 labials 16 ; 3 — 4 rows of inteorbital scales, bounded in front by two shields. 

 Yellow stripe from eyebrow above rictus oris. Yellowish-brown, with a 

 dorsal series of truncate, brown, yellow-edged rhombs; tail black-ringed. 

 {Kenn.) Arizona. 



Colors resembling somewhat those of C. adamanteits. About thirty dor- 

 sal rhombs. Rostral higher than wide, upper angle acute. Internasals and 

 prefrontals regular, without small scales or plates around them. A pair of 

 plates between the front portions of the supraciliaries and a pair of smaller 

 ones behind them. Anterior portion of the nasal twice the size of the 

 posterior. Two small loreals, one above the other. One or two rows of 

 scales between the labials and suborbitals. Scales in 25 series. Ventrals 

 172+21. Taken by Dr. Edw. Palmer near San Luis Potosi, Mexico. 



var. atrox. 



Crotalus atrox Beard & Girard, 1853, Cat Serp., pp. 5 and 156. 



Marked by bleached colors, shortening of the rhombs in the dorsal series 

 and increase in their number and tendency posteriorly to fuse with the 

 lateral spots. Sometimes the anterior infralabials are divided, forming a 

 small pair of submentals behind the mental. Labials 14 — 19. Scales in 

 25—27 rows (25—20). outer two or three smooth. Ventrals 179—186+ 

 29 — 24, one to several of the subcaudals paired. Hab. Texas to Mexico. 



Crotalus molossus. 



Crotalus molossus Baird & Girard, 1853, Cat. Serp., 10. 



Two internasals. Four prefrontals. A pair between the supraciliaries 

 in contact with each other and the prefrontals. Labials 18. Infralabials 

 17. Scales in 29 rows. 



Yellowish. With a dorsal series of rhombs similar to those of C. ada- 

 manteits, with the outer angle produced down the side as a vertical bar, 

 centers light, confluent anteriorly. Ventrals 187+25. New Mexico. 



Mem. — vol. n — 8. 



