DALL: MOLLUSCA AND BRACHIOPODA. 243 
Cylichnella (Cylichnium) pizarro Datt, n. sp. 
Plate 11, figure 1. 
Shell small, subcylindric, blunt behind, with the spire immersed, showing only 
a minute apical perforation; yellowish white with a thin, translucent polished peri- 
ostracum ; inner lip with a thin wash of callus; outer lip behind appressed toward 
but not quite touching the apex of the last whorl, gyrate, laterally straight, the 
lateral profile gently, convexly arcuate; margin thin, simple, slightly produced 
and excavated in front, and passing with but a hardly perceptible angle into the 
short straight pillar; over the latter is a wash of callus, but behind it no umbilical 
chink ; sculpture of fine, close, spiral lines, microscopically punctate, and tending 
to arrange themselves in pairs; near the shoulder of the whorl are six or seven 
much stronger subequal and nearly equidistant spirals, apparently not punctate ; 
inner lip quite smooth and the pillar unarmed; axis not pervious. Lon., 9.75; 
max. lat., 5.0 mm. 
U.S. 58. “ Albatross,” station 3392, off the Gulf of Panama in the Pacific, in 
1270 fathoms, bottom temperature 36°. 4 F. U.S. N. Mus. 123,079. 
The form of this species is not unlike that of Cylichna crispula Watson, from 
North Australia, but the latter is a very much smaller shell, has the outer lip 
more produced behind the apex, and the aperture in front more contracted. 
Cylichnella (Cylichnium) atahualpa Datzt, n. sp. 
Plate 11, figure 2. 
Shell small, elongate, white with a pale yellowish periostracum which shows 
reddish brown in the incised sculpture; the aperture as long as the shell, the 
general form attenuated toward the extremities, especially in front, but moder- 
ately convex near the middle of the whorl; spire entirely concealed, the summit 
forming a shallow funnel, owing to the gyration of the posterior margin, about 
half of which is occupied by a deep rounded sulcus; apex imperforate but with a 
reflected edge of callus on the body, forming a chink at the bottom of the funnel ; 
exterior polished, smooth except for faint lines of growth, but with a very few 
fine incised punctate lines close to the anterior and posterior margins of the shell ; 
body with a thin callus with a brown line at the outer edge; outer lip thin, sharp ; 
aperture narrow, deeply sulcate at each end; pillar simple, gyrate but not pervi- 
ous, short and thick, with a little callus reflected upon it. Lon., 9; max. diam., 
4 mm. 
U. 8. 8. “ Albatross,” station 3354. Gulf of Panama, in 322 fathoms, mud, 
bottom temperature 46° F. U.S. N. Mus. 123,081. 
Bullarvidae. 
BULLARIA RarinesQue. 
Bulla Linné, Syst. Nat., 1758, ed. 10, p. 725; 1767, ed. 12, p. 1181; not of Linné, 
op. cit., ed. 10, p. 427, nor of Muller, Prodr. Zool. Dan., 1776, p. 242. 
