262 



CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Variation. — The loreal is 1 — 1 in all our specimens. The 

 preociilars are 1 — 1 in all. The postoculars are 3 — 3 in two, 

 3 — 4 in two, and 4 — 4 in two. The temporals are 1+3 — 1+3 

 in four, 1+2—1+2 in three, and 1+3—2+3 in one. The 

 supralabials are 8 — 8 in twelve, 7 — 8 in one. The infralabials 

 are 10 — 11 in four, and 10 — 10 in two. The scale-rows are 

 21—19—17 in ten, 21—21—17 in one, 23—23—17 in one, 

 and 21 — 26 in one. The gastrosteges vary in number from 

 149 to 162, males having from 157 to 162, females from 149 

 to 159; the average in six males is 160.5, in eight females, 

 154.9. The urosteges vary from 63 to 79, males having from 

 77 to 79, females from 63 to 67 ; the average in two males is 

 78, in four females, 64.7. These variations are shown in full 

 in the following- table of scale-counts. 



Remarks. — IMarcy's Garter-snake may usually be distin- 

 guished at a glance 1)y its postoral crescents and the position of 

 its lateral line. The dorsal spots of certain specimens resemble 

 those of certain specimens of T. o. vagrans, but usually are 

 larger. The gastrosteges ordinarily lack the dark markings 

 which are so constant in T. o. vagrans, but frequently are 

 marked with black laterally. The posterior genials usually 

 are longer than the anterior. 



Our specimens from Tucson were caught in mud puddles on 

 the desert a mile or more from the river. 



