40. THAMNOPHIS 795 



181. Thamnophis sirtalis concinnus (Hallowell) 

 Northwestern Garter Snake 



TropidonoU4s concinnus Hallowell, Proc. Acad. Nat. Sci. Phila., Vol. 



VI, 1852, p. 182 (type locality, Oregon Territory). 

 Eutainia pickeringii Baird & Girard, Cat. N. Amer. Rept., Ft. i, Serp., 



1853, p. 27 (type locality, Puget Sound); Girard, U. S. Explor. 



Exped., Herp., 1858, p. 150, pi. XIII, figs. 14-20; Lord, Naturalist 



Vancouver Island, Vol. 11, 1866, p. 306 (part). 

 Eutainia concinna Baird & Girard, Cat. N. Amer. Rept., Ft. i, Serp., 



1853, p. 146; Lord, Naturalist Vancouver Island, Vol. II, 1866, 



p. 306. 

 Eutcsnia sirtalis tetratania Cope, U. S. Explor. Surv. W. looth Merid., 



Vol. V, 187s, P- 546 (part); Cope, Proc. U. S. Nat. Mus., Vol. 



XIV, 1892, p. 664 (Puget Sound, Wash., and Pitt River, Cal.) 



(part); Cope, Report U. S. Nat. Mus., for 1898, igcxD, p. 1080 



(part). 

 Eutania sirtalis concinna Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, 



p. 664; Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 1081. 

 Eutania sirtalis pickeringii Cope, Proc. U. S. Nat. Mus., Vol. XIV, 



1892, p. 665, Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 



1082; Ditmars, Reptile Book, 1907, p. 238, pi. LXXII, fig. 2. 

 Eutania sirtalis trilineata Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, 



p. 665, ("Port Townsend, Oregon and Fort Benton, Mont.") 



(part?); Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 1083 



(part?). 

 Thamnophis parietalis pickeringii Van Denburgh, Occas. Papers, Cal. 



Acad. Sci., V, 1897, p. 204. 

 Thamnophis sirtalis concinnus Ruthven, Bull. U. S. Nat. Mus., No. 61, 



1908, p. 173; Stejneger & Barbour, Check List N. Amer. Amph. 



Rept., 1917, p. 103; Van Denburgh & Slevin, Proc. Cal. Acad. 



Sci., Ser. 4, Vol. 8, No. 6, p. 192; Smith, Copeia, 1920, No. 88, 



p. 102; Van Denburgh & Slevin, Proc. Cal. Acad. Sci., Ser. 4, 



Vol. XI, 1921, pp. 40, 45. 

 Thamnophis sirtalis parietalis Blanchard, Copeia, 1921, No. 90, p. 6. 



Description. — Head distinct from neck, flat topped, with 

 narrow, rounded snout. Temporal regions sometimes swol- 

 len in old specimens. Eye large. Rostral plate large, bound- 

 ed behind by internasal, anterior nasal and first labial plates. 



