192 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Thamnophis sirtalis concinnus (Hallowell) 

 Northwestern Garter-Snake. 



Diagnosis. — Squamation similar to that of T. s. parietalis. 

 Gastrosteg"es and urosteges average fewer than T. s. infernalis. 

 Coloration usually darker than in either T. s. parietalis or T. s. 

 infernalis. 



Type Locality. — Oregon Territory. 



Synonyms. — Eutcenia pickeringii Baird & Girard, 1853 ; type 

 locality Puget Sound. EutcEnia sirtalis trilineata Cope, 1892; 

 type localities "Port Townsend, Oregon", and Fort Benton, 

 Montana. Eutcenia sirtalis tetratcunia (part?), Cope, 1875, no 

 locality, and 1892, Puget Sound, Washington. 



Range. — The coast region of British Columbia, Washington, 

 Oregon, and California south to San Francisco Bay, intergrad- 

 ing toward the south and east in California with T. s. infernalis. 

 In the far north, probably ranging east to Idaho, or possibly 

 Montana. 



We have examined specimens of Thamnophis sirtalis con- 

 cinnus from the following localities : — 



1. Lillooet River Valley, British Columbia. 



2. Union Bay, Bayne Island, B. C. 



3. Vancouver Island, B. C. 



4. Alberni Valley, Vancouver Island, B. C. 



5. Blue Lakes, Twin Falls Co., Idaho. 



6. Weiser, Washington Co., Idaho. 



7. San Juan Islands, Washington. 



8. Lake Crescent, Clallam Co., Wash. 



9. Darrington, Snohomish Co., Wash. 



10. Seattle, King Co., Wash. 



11. Quiniault, Chehalis Co., Wash. 



12. Melbourne, Chehalis Co., Wash. 



13. Longmire, Pierce Co., Wash. 



14. Pierce Co., Wash. 



15. Pullman, Whitman Co., Wash. 



16. South Bend, Pacific Co., Wash. 



17. Holcomb, Pacific Co., Wash. 



18. Olney, Clatsop Co., Oregon. 



