SNAKES OF THE GENUS PITUOPHIS 171 



In both the extremes of variation and the average, the number of 

 ventrals shows a rather marked decrease from south to north (fig. 

 74). while the tail length shows a decided tendency to increase over 

 the same territory (fig. 77). The labials and oculars (fig. 76) remain ex- 

 tremely constant throughout the range of the form, exhibiting in each 

 case a very slight tendency toward decrease in number from south to 

 north. No evidence of geographic variation in the number of dorsal 

 spots seems to exist (fig. 78), and the averages for the different regions 

 considered lie between 54 and 59 for the body spots, and between 69 

 and 76 for the total number. 



The observable sexual variation may be summarized as follows: 

 The scale rows average slightly higher in females than in males; ven- 

 trals vary from 217 to 249 (average 233.0) in males from 214 to 259 

 (average 238.3) in females; caudals 57 to 71 (average 65.4) in males, 

 54 to 67 (average 59.2) in females; supralabials, infralabials, and 

 preoculars average slightly higher in females than in males, while 

 postoculars are slightly higher on the average in males; body spots 

 average 57.7 in males, 55.4 in females; tail spots average 17.3 in males, 

 15.2 in females; tail length forms 0.129 to 0.166 (average 0.145) of the 

 total length in males, 0.115 to 0.159 (average 0.135) in females. 



One specimen from Salt Lake City, Utah (A.N.S.P. No. 10387), is 

 abnormal m the presence of two frontals. 



Range. — This snake ranges from the eastern desert regions of Cali- 

 fornia throughout the States of Utah and Nevada to western Colorado, 

 and north to Idaho and the western parts of Oregon and Washington. 

 Specimens have been examined from the following localities: 



California: Fresno County, Dunlap, Mercey Hot Springs, Fresno; Imperial 

 County, Brawley; Inyo County, Coso Valley, Shoshone, Owens Valley, Lone 

 Pine, 10 miles south of Owens lake, Shepard Canyon in Argus Range, Sur- 

 prise Canyon in Panamint Mountains, Jackass Spring in Panamint Moun- 

 tains; Kern County, Wheeler Ridge, Isabella, Edison Station, 8 miles north- 

 east of Bakersfield, Walker Pass; Mono County, Benton; Riverside County, 

 Mecca, Palm Springs; San Bernardino County, Victorville, between Hinchley 

 and Barstow; San Luis Obispo County, Palo Prieta Canyon. Other California 

 specimens bore the labels "Lone WiUow Springs" and "Wild Rose Springs," 

 localities that could not be found, and the indefinite record "Colorado River." 



Nevada: Clark County, Virgin Valley, opposite Fort Mohave in southeast Nevada; 

 Elko County, Carlin; Esmeralda County, Palmetto Mountains; Humboldt 

 County; Big Creek in Pine Forest Mountains, Thousand Creek, south fork of 

 the Humboldt River, Winnemucca; Nye County, Round Mountain; Ormsby 

 County, Carson City; Washoe County, Pyramid Lake; White Pine County, 

 Piermont (or Pyrmont, 75 miles east of Eureka). Other specimens had the 

 indefinite records "Peavine Creek in Toyabe Range" and "Truckee River." 



Utah: Beaver County, Beaver Creek Hills; Grand County, Thompson, Moab; 



Juab County; Millard County, 20 miles northwest of Delta, 30 miles north of 



Delta, 8 miles northeast of Delta, Fillmore, Kauosh; Salt Lake County, Salt 



Lake City, Fort Douglas; Uinta County, near Jensen, White River, Ouray 



136423—40 12 



