CLASS GASTROPODA 
113 
vertical axial ribs. Later whorls increasing more rapidly in diameter, less 
elevated between axial ribs, which become decidedly enfeebled as they ap¬ 
proach the summit. There are almost 40 axial ribs upon the first, 34 upon 
the second, 30 upon the third, 25 upon the fourth, 20 upon the fifth to 
eleventh, and 22 upon the penultimate whorl. Intercostal spaces mere 
lines, on the first whorl, on the later ones shallow impressed areas of about 
half the width of the ribs. Sutures well-marked. Periphery of the last 
whorl inflated. Base short, well-rounded, posterior portion marked by the 
very feeble extensions of die axial ribs; the anterior smooth, excepting the 
very fine and exceedingly closely spaced spiral striations, which cover the 
entire surface of the shell. Aperture subquadrate; posterior angle obtuse; 
outer lip thin, showing the external sculpture within; columella slender, 
slightly twisted. Length, 7.2; diameter, 2.2 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 152751a. Type locality, 
off San Pedro, California. 
Range. San Pedro to San Diego, California. 
Turbonilla pugetensis Bartsch, 1917 
Plate 51, fig. 4 
Proceedings of the United States National Museum, 52 :647; PL 44, fig. 4. 
Shell small, elongate-conic, wax-yellow with a broad band of pale 
brown which extends posterior from the periphery, gradually fading into 
the general lighter color. Nuclear whorls and early post-nuclear turns 
decollated in all our specimens; those remaining feebly shouldered at the 
summit, flattened in the middle, becoming considerably contracted and 
rounded toward the suture, marked by broad, well-rounded, slightly pro- 
tractive, axial ribs which become somewhat enfeebled and expanded to¬ 
ward the summit. Of these ribs 16 occur upon all of the turns remaining 
excepting the last, which has 18. Intercostal spaces shallow, about as wide 
as the ribs. Suture moderately contracted. Periphery of the last whorl 
well-rounded. Base somewhat inflated, well-rounded, marked by the feeble 
continuations of the axial ribs, which become evanescent before reaching 
the middle of the base and numerous very fine spiral striations, which are 
also present on the spire. Aperture broadly oval; posterior angle acute; 
outer lip thin, showing the external sculpture within; inner lip decidedly 
oblique, slender and somewhat revolute; parietal wall glazed with a very 
thin callus. Length, 4; diameter, 1.5 mm. (Bartsch.) 
Type in United States National Museum, No. 268754. Type locality, 
Northwest Point, Elliot Bay, Seattle, Washington. 
Range. Puget Sound, Washington. 
[411] 
