150 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
Turbonilla periscelida Dali and Bartsch, 1909 
Plate 56, figs. 6, 6 a 
Bulletin 68, United States National Museum, 119; PI. 11, figs. 6, 6a. 
Shell pupiform, milk-white, shining. Nuclear whorls small, two, form¬ 
ing a depressed helicoid spire, whose axis is at right angles to that of the 
succeeding turns, in the first of which it is about one-half immersed. Post- 
nuclear whorls flattened, slightly contracted at the sutures, appressed at 
the summit, with a strong, sloping shoulder which extends over the 
posterior fourth of the space between the sutures, marked by strong, 
vertical axial ribs, of which about fourteen occur upon all the whorls. 
These ribs become flattened and decidedly expanded on the shoulder. 
Intercostal spaces about three times as wide as the ribs, shallow, smooth. 
Sutures slightly contracted. Periphery of the last whorl somewhat attenu¬ 
ated, base well-rounded, smooth. Aperture oval; somewhat effuse an¬ 
teriorly; posterior angle acute; outer lip re-enforced by three, broad, 
internal spiral lirations, two of which are posterior to the periphery and 
the other immediately below it; columella decidedly twisted and somewhat 
revolute; re-enforced by the base, provided with a very strong, oblique fold 
at its insertion; parietal wall covered by a thin callus. Length, 3.2; 
diameter, 1 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 163266. Type locality, 
United States Bureau of Fisheries Station 2901, off Santa Rosa Island, 
California. 
Range. Known only from type locality. 
Subgenus Bartschella Iredale, 1917 
Turbonilla laminata Carpenter, 1856 
Annals and Magazine of Natural History, series 3, 396. Bulletin 68, United States 
National Museum; PI. 12, fig. 16. 
D. testa satis elevata, rufo-fusca, fasciis pallidioribus interdum cincta; 
anfra. nucl. ii, helicoideis, valde decliviter sitis, margines spirae subrectos 
haud superantibus; norm, viii., subrotundatis, suturis impressis; costis 
spiralibus rotundatis, in spira iv, aliisque suturalibus vix rotundatis, 
interstitiis minoribus impressis; super eas laminis rantiantibus acutiori- 
bus circ. xxx, circa basim rotundatum tenuiter continuis, liris spirali¬ 
bus basalibus circ. viii, obtusis, columellan versus subflexuosam obsoletis; 
peritremate continuo; labio appresso. Long., .25; long, spir., .18; lat., .07 
poll. (Carpenter.) 
[448 ] 
