41. SONORA 



or greenish white, unmarked except on the tail, where the 

 dorsal dark markings may be extended across the urosteges 

 more or less obsoletely. 



Length to anus...... .171 194 228 230 260 



Length of tail 44 44 54 56 



Remarks. — In coloration this snake is more or less inter- 

 mediate between 5. episcopa and 5. occipitalis. Its trans- 

 verse black bars cause it to resemble the latter, while the 

 tendency toward lateral lines recall the former species. The 

 snout is very different from that of S. occipitalis but is like 

 that of 5. episcopa. S. semiannulata may be said to be prac- 

 tically 5. episcopa with black dorsal cross-bars. Its colora- 

 tion reminds one in many ways of that of Rhinocheilus 

 lecontei. 



Distribution. — Originally described from Sonora, this 

 little snake has since been taken in Texas, Kansas, Arizona, 

 Utah, and Nevada. 



Arizona specimens have been recorded by Cope from 

 Fort Whipple, Fort Verde, Prescott, and Fort Mohave, and 

 I have seen others from the Huachuca Mountains, Cochise 

 County, and Cave Creek, Maricopa County. 



In Utah, it has been taken at Rockville, Kane County, 

 and near St. George, Washington County. 



In Nevada, one was captured at Pyramid Lake, Washoe 

 County, and one at Rhyolite, Nye County. 



Habits. — Nothing is known concerning the habits of this 

 little snake. The specimen from Pyramid Lake was found 

 under a rock on a rise above the southwest shore of the Lake. 



