40 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Vertex obtusely truncated, slightly concave in the middle; base rounded; 
aperture not very narrow, dilated below, the outer lip projecting above 
the crown of the shell, a little arcuate and indexed in the middle; 
columella nearly straight, with a broad fold. Surface smooth, polished, 
shining, but covered with many impressed undulating lines, which are 
quite conspicuous. (Tryon and Pilsbry, Manual of Conchology.) 
Type in Boston Society of Natural History? Type locality, Westbrook, 
Maine. Described from a fossil. 
Range. Point Barrow, Aleutian Islands; circumboreal. 
Cylichnella diegensis Dali, 1919 
Proceedings of the United States National Museum , 56:300. 
Shell small, thin, cylindric, white, with a pale straw-colored peri- 
ostracum with reddish brown spiral lines on the base and near the apex; 
whorls involved, the apex exhibiting a funicular depression ending in a 
minute perforation; the surface smooth and polished except for faint 
incremental lines; aperture very narrow, the outer lip thin, straight, recurv¬ 
ing deeply around the apex, at the base receding and rounding into the 
simple, thickened pillar lip; body with a slight glaze. Length, 8; diameter, 
3.5 mm. (Dali.) 
Type in United States National Museum, No. 209071. Type locality, 
United States Fish Commission Station 4359, off Point Loma, San Diego 
County, California. 
Range. San Diego, California, to Cape San Lucas; Vancouver 
Island. 
Cylichnella attonsa Carpenter, 1865 
Plate 2, fig. 8 
Proceedings, Philadelphia Academy of Natural Sciences, 58. 
C. t. C. cylindrical aliter simillima; sed postice rotundata, haud umbili-, 
cata, vix lacunata, labro regulariter incurvato. Long., .38; lat., .15. 
(Carpenter.) 
“Rounded off at apex.” (Carpenter.) 
Shell elongate, cylindrical; sides straight; white with a light-colored 
epidermis; with a tracing of orange around the outer edge of the inner 
lip. Aperture very narrow for two-thirds of the length, and widening out 
below. Columella slightly twisted; sculpture -consists of fine hair lines 
running concentrically around the shell. (Oldroyd.) 
Type in Philadelphia Academy of Natural Sciences. Type locality, 
Puget Sound. 
Range. Puget Sound to San Diego, California. 
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