Vol. VIII] VAN DENBURGH AND SLEVIN— GARTER-SNAKES 223 



Remarks. — This is the common garter-snake of the north- 

 west coast. It is of small size. The largest specimen exam- 

 ined measures 590 mm. to base of tail. The head is small, not 

 so distinct from the neck as in other races, and the labials are 

 reduced in number. 



The coloration is very variable. The dorsal line frequently 

 is absent or developed only on the neck. The lateral lines also 

 may be absent. Specimens may be heavily spotted or without 

 any marking, either lines or spots. The dorsal line usually is 

 yellow but may be red, and there often is red elsewhere in the 

 coloration, as on the gastrosteges. The lower surfaces often 

 are dark, and the coloration everywhere may be very dusky. 



Specimens with heavy spotting and dark pigmentation of the 

 gastrosteges resemble T. o. vagrans, but usually may be easily 

 distinguished by their scale characters. 



Specimens showing no dorsal line resemble T. o. couchii, but 

 here again the scale characters are quite different. 



The closest relationship of this subspecies undoubtedly is 

 with T. 0. atratns, yet there can be no doubt as to the subspecific 

 distinctness of the two forms. The differences in the number 

 of superior and inferior labials, scale-rows and gastrosteges 

 should be sufficient aid toward their correct determination, and 

 the general appearance usually is quite different. Certain 

 specimens, however, are so nearly intermediate in one or more 

 of their characters that students might differ in opinion as to 

 their identity. Such specimens, as set forth under head of T. 

 o. atratns, show real geographic intergradation. So far as 

 specimens examined by us show, this intergradation occurs 

 only in Del Norte County, California, where the ranges of the 

 two forms meet and perhaps overlap slightly. Many of the 

 specimens from this county are typical of either one or the other 

 subspecies, — ordinoides or atratus, — and most of the inter- 

 grades seem to be nearer to the latter type than to the former. 

 South of Del Norte County no tendency toward T. o. ordinoides 

 has been observed in T. o. atratns, unless it be that the rather 

 frequent absence of the dorsal line in specimens from Hum- 

 boldt and Mendocino counties may be so regarded. 



Ruthven considered two preoculars to be a character of 

 much importance in T. o. ordinoides. Our figures show that 



