940 REPORT OF NATIONAL MUSEUM, 1898. 



Eye small, diameter twice in length of muzzle. Preorbital narrower 

 above, not extending above lower margin of superciliary; loreal twice 

 as long as liigb. Prefrontals and internasals much broader than long; 

 frontal slightly angulate in front, longer than broad; parietals rather 

 elongate, subtruncate behind. Postorbitals subquadrate, temporals 



1-2. Postgeneials minute, Superior labials 



seven, all higher than long, eye over third and 



fourth. Scales in fifteen rows, all broader 



than long. Tail four and two-fifths times in 



total length, which is 10.25 inches. Below 



immaculate; tail completely six-annulate. 



y. 239 Another specimen in the U. S. National Mu- 



chionactis EPiscopus isozoNus seum from Kockville, Kane County, Utah, 



Cope. from Mr. A. L. Siler, indicates a variety. 



^^•^- The bodv is longer than in the type, and is 



rort Whipple, Arizona. j^ twcuty-fivc black bars between 



Cat. No. 11417, U.S.N. M. J J 



these, and on top of muzzle vermdion, below 

 yellow. Scuta 167|, 52. In two specimens the top of the head is black ; 

 in another it is like the general ground color. In the same specimen 

 the dorsal bars are very faint. 



Cat. No. 11417; upper labials, 7; gastrosteges, 167 + 1; urosteges, 52; rows of 

 scales, 15. 



Urosteges in other specimens, fifty-one, fifty-two, fifty-three. 



I bave a specimen from Prof. W. T. Cummins from the Tule Canyon 

 in the Staked Plain of Texas. 



I suspect that the Sonora semiannulata of Baird and Girard was estab- 

 lished on an abnormal specimen of this species. That specimen is 

 remarkable in having the .superciliary plate divided symmetrically on 

 each side by a suture, which cuts off a ])]ate whose apex reaches the 

 parietal, and which Baird and Girard term a third postocular. The 

 muzzle was somewhat wrinkled, so as to produce folds of the integu- 

 ment. This led to the mistaken belief that the nasal is divided. 

 Omitting these two characters, there remains only a slightly more 

 protuberant rostral plate, which is not more, in my opinion, than an 

 individual peculiarity. The coloration is identical with that of the 

 C. e. isozonus. More specimens will be necessary to settle the question 

 definitely. Should the identification here suggested prove necessary, 

 the name of the species will stand as Ghionactis semianmilatus, with the 

 subspecies episcopus, torquatus, and semiannulatus. 



This form is further variable. In Cat. No. 1409G the number of gastros- 

 teges and urosteges is less than in the C. e. isozonus; the nasal and 

 loreal plates are of different shapes, and the rostral is more prominent. 

 The color is also difi'erent. Otherwise the plate and scale forms are the 

 same. 



The rostral is narrower when viewed from above, and is more pro- 

 duced both forward and backward. The nasal is produced backward 



