218 American Seas bells 



axial ribs, except for a rather strong, rounded varix behind the outer hp. Last 

 whorl with about a dozen or so Hght-brown, spotted, spiral threads over a 

 background of light yellowish gray. 3 to 5 fairly large teeth on the inside of 

 the outer lip, Siphonal canal short, sealed over in adults. Periostracum thin, 

 fuzzy, grayish with mauve-brown undertones. Interior of aperture light 

 mauve-brown, usually with a whitish, spiral band on the middle of the body 

 whorl. O. stearTisi Hemphill is the same. Very common in rocky rubble and 

 on wharf pilings. 



Ocenebra circumtexta Stearns Circled Dwarf Triton 



Figure 49b 



Moss Beach, California, to Lower California. 



% to I inch in length, spire V^ the length of the shell. Characterized by 

 very strong, rough spiral cords (15 on the body whorl, 6 on the whorls 

 above). Under a lens the cords are seen to consist of arched, crowded, raised 

 axial lamellae. The cords are often cream-white with the interspaces black- 

 brown. Axial ribs wide, low, rounded and 7 to 9 per whorl. Some specimens 

 are banded or have large, red-brown spots. A white form of this species was 

 unnecessarily named citrica Dall. A very abundant species on rocks at low 

 tide to 30 fathoms. 



Ocenebra poulsoni Carpenter Poulson's Dwarf Triton 



Plate 24k 



Santa Barbara, California, to Lower California. 



1 % to 2 inches in length; a sturdy shell with a semi-gloss finish. 8 to 9 

 nodulated, rounded axial ribs per whorl crossed by numerous very fine, 

 incised spiral lines and 4 or 5 larger, rounded, raised spiral cords. The latter 

 make nodules on the ribs. Siphonal canal narrowly open. Periostracum thin, 

 grayish or brownish and smoothish. When the periostracum is absent, the 

 shell is glossy-white with numerous, fine spiral lines of dark- to yellow- 

 brown. Aperture white. An exceedingly common species found in nearly 

 every region on rocks and wharf pilings. 



Genus Pterorytis Conrad 1862 

 Pterorytis foliata Gmelin Foliated Thorn Purpura 



Plate 24h 



Alaska to San Pedro, California. 



2 to 3 inches in length, with 3 large, thin, foliaceous varices per whorl 

 which are finely fimbriated on the anterior side. Numerous spiral cords are 

 rather prominent and of various sizes. Siphonal canal closed, its anterior tip 

 turned up and to the right. Base of outer lip with a moderately strong spine. 



