CLASS GASTROPODA 
121 
umbilical region. Entire surface marked by numerous closely placed 
spiral striations. Aperture pyriform, posterior angle acute, columella 
almost straight, obliquely inserted, slightly revolute. Length, 5.7; diam¬ 
eter, 1.4 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 196221. Type locality, 
Banks Island, British Columbia. 
Range. Known only from type locality. 
Turbonilla franciscana Bartsch, 1917 
Proceedings of the United States National Museum, 52:645; PI. 42, fig. 2. 
Shell elongate-conic, flesh-colored, excepting a broad chestnut band 
which covers the median third of the last whorl. This dark band really 
consists of two chestnut-colored zones, the anterior of which embraces 
half of the band, while the posterior is equal to one-fourth of the width 
of the dark area, the two being separated by a zone of a little lighter 
shade which is as wide as the posterior zone. Nuclear whorls decollated 
in all the specimens seen. Post-nuclear whorl rather high between the 
sutures, feebly shouldered at the summit, and slightly constricted at the 
periphery. Early post-nuclear whorls marked by low, rounded, broad, 
almost vertical axial ribs which are wider than the shallow impressed 
spaces that separate them. On the later whorls the axial ribs become 
quite obsolete. On the first of the post-nuclear whorls there are eighteen 
of these ribs; on the second to fourth, twenty; on the fifth, they become 
decidedly feeble; and on the remainder they are not at all differentiated. 
In addition to the axial sculpture the surface of the shell is marked by 
very fine, wavy, closely spaced, spiral striations. Periphery of last whorl 
well-rounded. Base moderately long, well-rounded, marked by lines of 
growth and spiral striations comparable to those on the spire. Aper¬ 
ture broadly oval; outer lip thin, showing the color markings within. 
Columella curved, somewhat twisted, and slightly revolute; parietal wall 
glazed with a thin callus. Length, 6.8; diameter, 2 mm. (Bartsch.) 
Type in United States National Museum, No. 214435. Type locality, 
U.S. Steamer “Albatross” Station 5743, in 10-15^4 fathoms, San Fran¬ 
cisco Bay, California. 
Range. Known only from type locality. 
Turbonilla pedroana Dali and Bartsch, 1903 
Plate 52, figs. 12, 12a 
Memoirs of the California Academy of Sciences, 3: 279; PI. 2, figs. 3, 3a. (Arnold.) 
Shell elongate-conic, posterior two-thirds between the sutures light 
brown, anterior third and base darker, the two areas being separated 
by a still darker band. (Nuclear whorls decollated.) Post-nuclear whorls 
[419] 
