144 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
flattened, more or less regular and evenly retractive axial ribs, of which 
about 22 appear upon the third, 26 upon the fifth and 40 upon the seventh 
whorl. On the penultimate and antepenultimate whorls they are more or 
less irregular in form, number, and spacing. Intercostal spaces much nar¬ 
rower than the ribs. The spiral sculpture consists of eight deep, quite regu¬ 
larly spaced lines of pits, which are very pronounced in the intercostal 
spaces and on the sides of the ribs, but do not appear to cross their sum¬ 
mits except on the penultimate and last whorl. Sutures well-defined, 
simple. Periphery and base of the last whorl evenly rounded, the latter 
ornamented by the prolongation of the axial ribs and quite a number of 
continuous well-impressed spiral lines with faint spiral striation between 
them. Aperture suboval, somewhat effuse anteriorly, posterior angle ob¬ 
tuse (outer lip fractured, very thick) ; columella strong, slightly curved, 
and strongly revolute, with a weak, very oblique, internal fold near its 
insertion; parietal wall and umbilical region covered by a weak callus. 
Columella and extreme anterior portion of the aperture white. Length, 
13.5 ; diameter, 3.7 mm. (Dali.) 
Type in United States National Museum, No. 74000. Type locality, 
Monterey, California. 
Range. Known only from type locality. 
Subgenus Mormula A. Adams, 18o4 
Turbonilla regina Dali and Bartsch, 1909 
Plate 56, fig. 1 
Bulletin 68, United States National Museum, 112; PI. 11, fig. 1. 
Shell very large, elongate-conic, slender, pale-chestnut. (Nuclear whorls 
decollated.) Post-nuclear whorls well-rounded, appressed at the summit, 
moderately constricted at the periphery, marked at irregular intervals by 
strong varices and by very regularly narrow, low, rounded, slightly pro- 
tractive, axial ribs, of which 16 occur upon the first and second, 18 upon 
the third, 22 upon the fourth, 24 upon the fifth to seventh, 30 upon the 
eighth and ninth, 36 on the tenth, 40 on the eleventh and the penultimate 
whorl. Intercostal spaces about one and one-half times as wide as the ribs, 
marked by six well-incised spiral lines, which extend strongly upon the 
sides of the ribs and weakly over them; the space between these lines is 
marked by numerous exceedingly fine, spiral striations. Sutures constricted. 
Periphery of the last whorl slightly angulated, marked by an incised spiral 
line. Base short, well-rounded, marked by the feeble continuations of the 
axial ribs and numerous very fine, closely spaced, wavy, spiral striations. 
Aperture rhomboidal; posterior angle obtuse; columella strong, almost 
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