216 American Seashells 



Thais canaliculata Duclos Channeled Dogwinkle 



Figure 48b, c 



Aleutian chain to Monterey, California. 



I inch in length, moderately globose, its spire higher than that of emar- 

 ginata, but lower than that of lamellosa. Columella arched, flattened below. 

 Characterized by about 14 to 16 low, flat-topped, closely spaced, spiral cords 

 on the body whorl. Suture slightly channeled. Color white or orange- 

 brown, often spirally banded. Moderately common on rocks and mussel beds. 

 Do not confuse with lima from Alaska. 



Thais emarginata Deshayes Emarginate Dogwinkle 



Figure 48a 



Bering Sea to Mexico. 



I inch in length, with a rather short spire and with globose whorls. 

 Aperture large. Columella strongly arched, and flattened and slightly con- 

 cave below. Sculpturing variable, but characteristically with coarse spiral 

 cords, usually alternatingly small and large. Cords often scaled or coarsely 

 noduled. Exterior yellow-gray to rusty-brown, often with darker, narrow 

 spiral bands. Interior and columella light- to chestnut-brown. Exceedingly 

 common in many places along the coast where there are rocks. 



Thais lima Gmelin File Dogwinkle 



Figure 486 



Alaska and Japan to northern California. 



I to 2 inches in length, very similar to ca7ialiculata, but with 17 to 20 

 round-topped spiral cords, often smooth, sometimes minutely fimbriated. 

 Cords often alternate in size. Color whitish or orange-brown, rarely banded. 

 Common intertidally. Compare with canaliculata. 



Genus Ocenebra Gray 1847 



Tritonalia Fleming 1828 may also be used as a name for this genus, al- 

 though Ocenebra would seem to be the wiser choice and will probably be 

 the final choice. Ocinebra is a misspelling. 



Ocenebra interfossa Carpenter Carpenter's Dwarf Triton 



Figure 49a 



Alaska to Lower California. 



/4 to % inch in length, spire half the length of the shell; light-gray in 

 color, delicately sculptured. 8 to 1 1 axial ribs on the body whorl crossed by 

 about a dozen strong, microscopically scaled spiral cords. The surface is 



