CLASS GASTROPODA 
101 
Intercostal spaces about one-half as wide as the ribs, but little depressed 
below the general surface of the shell. Sutures somewhat constricted. 
Periphery of the last whorl well-rounded. Base short and somewhat 
inflated, marked by feeble extensions of the axial ribs. Entire surface 
of spirals and base crossed by numerous fine wavy, spiral striations. 
Aperture subquadrate, rather elongated, posterior angle obtuse, outer lip 
thin; columella rather long, slender, slightly sinuous. Length, 7.9; diame¬ 
ter, 1.7 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 160065. Type locality, 
San Pedro, California. 
Range. Known only from type locality. 
Turbonilla simpsoni Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 49; PI. 3, figs. 6, 6a. 
Shell elongate-conic, rather slender, bluish-white. Nuclear whorls two 
and three-fourths, depressed, heliocoid, having their axis at right angles 
to that of the succeeding turns, in the first of which they are about one- 
fourth immersed. Post-nuclear whorls well-rounded, marked by very 
strong, well-raised, almost vertical, axial ribs, of which sixteen occur 
upon all the whorls of the type. These ribs are strongest in the middle 
and slightly lower on the summit and periphery. Intercostal spaces deeply 
impressed, equaling the ribs in width, terminating a very little posterior 
to the suture. Sutures somewhat constricted. Periphery of the last 
whorl well-rounded. Base rather short, well-rounded. Entire surface 
of the spire and base marked by fine wavy, spiral striations. Aperture 
subquadrate, posterior angle obtuse; outer lip thin, showing the external 
sculpture within; columella short, slender, and oblique. Length, 6.7; 
diameter, 1.6 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 152750. Type locality, 
San Pedro, California. 
Range. Off Redondo to San Diego, California. 
Turbonilla profundicola Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 50; PI. 3, figs. 11, 11a. 
Shell elongate-conic, milk-white, shining. Nuclear whorls very small, 
two and one-half, depressed, helicoid, having their axis at right angles 
to that of the succeeding turns, in the first of which they are but slightly 
immersed. Post-nuclear turns well-rounded, very slightly shouldered at 
the summit, marked by gently protractively curved, low, rounded, well- 
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