(524 ZOOLOGY— REPTILES AND BATRACH1ANS OF ARIZONA. 



by a narrow interval. Abdomen with subquadrate black spots opposite the 

 former and their intervals. 



07. Gyalopium canum. Cope. 



Plate XVIII, Fig 2, 2a 

 Gyalopion canum, Cope, Proc. Acad. Nat. Sci. Pliila., 1800, 243. 



Gyalopium canum, Con;, Proc. Acad. Nat. Sci. Pliila., 1S60, 310. — Id., Check-List, 

 1875, 30. 



Prefrontals triangular, not larger than preoculars. Postoculars of equal 

 size. Anterior border of vertical not angulated. Occipitals as broad as long, 

 truncate posteriorly. Superior labials 7, eye over third and fourth. Interior 

 labials 7, fourth largest. Geneials one pair, very short. Scalesin 17rows,nearly 

 square. Gastrosteges, 130; one anal; urosteges,28. Total length, 7^ inches; 

 tail, 11 lines. Above brownish-gray, crossed by .">1 irregular transverse 

 brown bands : these are from one to three scales wide on the back, and extend 

 to the o-astrosteires ; anteriorlv they exhibit a tendency to divide into a dorsal 

 and two lateral scries of spots; 8 transverse spots on the tail; first spot on 

 the neck large, produced medially to the occipitals. A brown band extends 

 from one angle of the mouth to the other across the occipitals, involving the 

 tip of the vertical; another brown band commences on the upper borders 

 of the lower labial shields, passes through the eve, and crosses the anterior 

 parts of the superciliaries, and vertical and posterior parts of postfrontals 

 and rostral. Dirty yellowish beneath, and upon the first row of scales. — 

 Descr. orig. 



"It is an extraordinary serpent, resembling, at hist sight, a diminutive 

 Heterorhn", and was discovered at Fort Buchanan, Ariz., by Dr. B. J. D. 

 Irwin, l\ S. A. 



(is. Sonora semiannulata, Bd. & Gir. 



Sonora semiannulata, Bd. & Gir., Cat. N. A. Rept., 1853, 117 (type of genus.) — Bd., 

 C S. & Mcx. Bound. Surv., ii, pt. ii. 1850, Reptiles, 21, pi. 10, f. 3.— COPE, 

 Proc. Acad. Nat. Sci. Pliila., 1S66, 310.— Id., Chock-List, 1S75, 30. 



Sonora and Southern Arizona. Not seen by me. 



CO. Chionactis occipitalis, (Hallow.) <'<>pr. 



il. OCCIPITALIS. 



Rliino&toma occipitale, Hallow., Proc. Acad. Nat. Sci. Pliila., vii, 1854, 05. 

 Lamprosoma occipitale, Hallow., Proc. Acad. Nat. Sci. Pliila., viii, 1850, 310. — Kenn. 

 apud Bd., U. S. & Mex. Bound. Surv., ii, pt. ii, 1850, Reptiles, 21, pi. 21, f. 1. 

 Chionactis occipitale, Cope, Proc. Acad. Nat. Sci. Phila., 1866, 310. 



