CLASS GASTROPODA 
191 
Type. Margarita (Turcicula ) imperialis Dali, 1881. 
Distribution. Atlantic, eastern Pacific, and Japanese seas. Fossil: 
Tertiary of the Pacific coast of North America. 
Turcicula bairdii Dali, 1889 
Bulletin, Museum of Comparative Zoology, 18:377. Dali, Proceedings of the United 
States National Museum, 12:346; PI. 7, fig. 3. 
Dali named this species and described the soft parts in Bulletin, 
Museum of Comparative Zoology, 18; the shell was described in the 
Report on the Voyage of the “Albatross” 
Shell large, turbinate, elevated, thin, inflated, with four and a half or 
five whorls, of which the last is much the largest; surface apt to be eroded, 
but where perfect covered with an extremely thin, dense, vernicose, pale 
apple-green epidermis; whorls inflated; suture deep, not channeled; apex 
moderately pointed; spiral sculpture of (1) numerous fine, faint, rather 
irregular scratches or impressed lines; (2) sparse, slightly elevated, re¬ 
volving bands which are usually more or less nodulous, the nodules when 
prominent being sharp and laterally flattened as if pinched up; of these 
there are on the upper whorls usually three series between the sutures, of 
which one at the periphery is the most prominent and persistent, the next 
one behind it, halfway between the periphery and the suture, being the 
least marked; on the base the cinguli are six or seven in number, becom¬ 
ing narrower toward the axis, smaller than those behind the suture, with 
smaller, less prominent, rounder, and more numerous nodules; there is 
some variation in number and strength of all the cinguli, but that on the 
periphery is the most prominent and constant; the whorls are particularly 
round and inflated above and below, so that the outline of the aperture is 
often nearly circular; interior of the aperture brilliantly pearly, a thin wash 
of callus on the body; the outer lip very slightly thickened and distinctly 
reflected In the adult; pillar thin, simple, arching roundly into the curve 
of the base without any interruption, angle, or tooth; axis imperforate; the 
external sculpture showing through the thin shell. Altitude, 50; maximum 
diameter, 42 mm. Maximum diameter of operculum, 18 mm., with about 
12 whorls. The operculum is externally polished, smooth, and deeply 
concave; the inner side presents a minute, central, rounded, elevated point; 
the margin is very thin but entire. 
Type in United States National Museum. Type locality, U.S.S. “Alba¬ 
tross” Station 2839, off San Clemente Island, California, in 414 fathoms, 
sand; bottom temperature not registered. 
[ 793 ] 
