CLASS GASTROPODA 
109 
somewhat overhanging, decidedly contracted toward the periphery from 
the anterior fifth of the exposed part; almost flattened posterior to this, 
and closely appressed at the summit, separated by strongly marked sutures. 
Ribs about 18 upon all the turns, almost vertical, moderately elevated, 
rounded in the middle, decidedly flattened and widened at the summit, 
disappearing at the periphery. Intercostal spaces not depressed below the 
general surface, a little wider than the ribs. Periphery and the moderately 
long base well-rounded, smooth, excepting the fine spiral striation which 
covers the entire surface of the shell. Aperture subquadrate, posterior 
angle acute; outer lip thin, showing the color bands within; columella 
slender, oblique and slightly revolute. Length, 5.4; diameter, 2.1 mm. 
(Dali and Bartsch.) 
Type in United States National Museum, No. 126660. Type locality, 
Port Simpson, British Columbia. 
Range. Port Simpson to Victoria, British Columbia. 
Turbonilla taylori Dali and Bartsch, 1907 
Plate 52, figs. 7, 7a 
Proceedings of the United States National Museum, 33:499; PI. 44, fig. 9. 
Shell very regularly elongate-conic, purplish-brown. Entire surface 
marked by numerous, closely placed, minute, spiral striations. Nuclear 
whorls small, depressed, helicoid, smooth, scarcely at all immersed, having 
their axis at a right angle to that of the later turns, the sides not projecting 
beyond the outline of the spire. Post-nuclear whorls quite high between 
the sutures, only slightly contracted toward the periphery and very weakly 
beveled at the appressed summits, marked by low, broad, retractive axial 
ribs, which are much more numerous and less strongly defined on the early 
whorls than on those succeeding. There are about 36 on the second, 30 
upon the third, 24 upon the fourth, and 26 upon the antepenultimate post- 
nuclear turn. On the last whorl they become irregular and irregularly 
spaced, showing senility. The ribs become flattened and less strongly de¬ 
fined toward the summit and the periphery, disappearing at the well- 
rounded periphery. Sutures well-marked. Base short, inflated, rounded. 
Aperture suboval, somewhat effuse anteriorly; posterior angle acute; outer 
lip thin, white edges, chestnut-brown within except at the very base, which 
is white; columella slender, twisted, and slightly revolute anteriorly. 
Length, 6.5; diameter, 1.9 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 196210. Type locality, 
Departure Bay, British Columbia. 
Range. Port Simpson to Vancouver Island, British Columbia. 
[ 407 ] 
