282 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Pleurotomella (Pleurotomella) esilda Datt, n. sp. 
Shell fusiform, the spire longer than the aperture, chalky, apically eroded, with 
a pale gray, very thin periostracum and about five remaming whorls; suture 
appressed with a slightly constricted anal fasciole in front of it and about sixteen 
subequal, low, rounded protractive ribs crossing the upper whorls from in front 
of the fasciole with subequal interspaces and, on the last whorl, ceasing rather 
abruptly near the periphery; these ribs are not particularly strong or abrupt at 
their beginning; spiral sculpture of six or eight faintly incised lines in front of the 
suture and on the fasciole, and beginning again on the base near the anterior ends 
of the ribs and continuous but not sharp over the base and canal; the band be- 
tween the two series includes the ribbed part of the whorl and is sculptured with 
irregular, more or less retractive, oblique, vermicular, more or less punctate mark- 
ings which override ribs and intervals with about the same strength as the spirals ; 
whorls moderately rounded, spire subacute; anal sulcus wide, shallow ; outer lip 
thin, simple ; body with a wash of callus extending also over the short, straight, 
obliquely truncate, slightly twisted pillar; canal short, wide. Lon. of five 
(decollate) whorls, 23.5; of last whorl, 16.0; of aperture, 11.0; max. diam. 9.7 mm. 
U.S. S. “ Albatross,” station 3395, Gulf of Panama, in 730 fathoms, rocky 
bottom, temperature 38°.5 F. U.S. N. Mus. 123,126. 
Not unlike the preceding in sculpture but larger, less compact, and with a dif- 
ferent minor sculpture. 
Pleurotomella (Pleurotomella) suffusa Datu. 
Plate 14, figure 10. 
Pleurotomella suffusa Dall, Proc. U. 8. Nat. Mus., 1889, 12, p. 308, pl. 12, fig. 10. 
U.S. 5S. “ Albatross,” station 2807, near the Galapagos Islands, in 812 fathoms, 
ooze, bottom temperature 38°.4 F. U.S. N. Mus. 92,533. 
Pleurotomella (Pleurotomella) parella Datt, n. sp. 
Plate 14, figure 4. 
Shell large, thin, elongate-fusiform, white with a very thin translucent perios- 
tracum, and about eight whorls exclusive of the (lost) nucleus; spire rather 
acute ; suture slightly appressed, whorl in front of it polished and slightly con- 
stricted; margin of the whorl here and there obscurely plicate by the incremental 
lines ; surface of the fasciole here and there marked by obscure, irregular, short, 
oblique, fine ridges at right angles to the lines of growth; in front of the fasciole 
are (on the penultimate whorl fourteen) low, feeble, protractively oblique ribs, with 
much wider shallow interspaces, hardly reaching the suture in front on the spire 
