190 APPENDIX F.— -REPTILES. 



the subquadrangular pattern has broken up the chain- work into isolated 

 portions, as in Ophibolus eximius or Grotalophorus tergeminus. The 

 intervals of the dorsal blotches are wide and darker in the middle, 

 while in C. atrox they are narrow, not linear, and unicolor. The sides 

 of the head present the usual light stripe from the posterior extremity 

 of the superciliary; it passes, however, to the angle of the jaw on the 

 neck, along the second row of scales above the labials. A second 

 stripe passes in front of the eye to the labials, widening there. A small 

 light vertical bar is seen below the pit, and another on the outer edge 

 of the rostral. On the superciliaries are two light transverse lines 

 enclosing a space nearly one-third of the whole surface. In C. atrox 

 there is a single median line. Sometimes, as in C. atrox, the single 

 blotches on the nape are replaced by two elongated ones parallel to 

 each other. 



Dorsal row of scales, 29; abdominal scutellse, 180; subcaudal ones, 

 27. Total length, 34 inches; length of tail, 4 inches. 



A specimen was collected the 5th of June in the Witchita mount- 

 ains. Another specimen of the same species was brought home from 

 the Cross-Timbers, Arkansas, by Dr. S. W. Woodhouse, and described 

 by Dr. Hallowell as new, under the name of Crotalus Lecontei, on the 

 ground that the anterior vertebral spots are not confluent. This we do 

 not consider as a sufficiently distinctive character, although we have 

 never seen a specimen with decidedly confluent markings. The notes 

 of Dr. Leconte, quoted by Dr. Hallowell, hardly apply to the present 

 species. 



The species was first discovered by Say, on Major Long's expedition to 

 the Rocky mountains, and has not since been seen until procured first 

 by Dr. Woodhouse, and then by Captain Marcy and the Mexican 

 boundary commission. It was found by the latter party in Western 

 Texas, where, however, it is rare. 



Plate I represents Crotalus confluentus of natural size. 



II. EUT-^ENDA, B. & Q. 



This genus is composed of numerous species, some of them quite 

 common, and known under the names of Riband, Striped, and Garter 

 snakes; inoffensive, like most of the North American snakes. They 

 mey be recognised by three light stripes on a darker ground, the inter- 

 vals between these stripes provided with alternating or tessellated 



