282 bulletin: museum of comparative zoology. 



Pleurotomella (Pleurotomella) esilda Dall, n. sp. 



Shell fusiform, the spire longer thau the aperture, chalky, apical ly eroded, with 

 a pale gray, very thia periostracum and about five remaiiiiug 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 frout 

 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 hues 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 3S°.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 Dall. 



Plate 14, figure 10. 



Pleurotomella sufusa Dall, Proc. U. S. Nat. Mus., 1889, 12, p. 308, pi. 12, fig. 10. 



U. S. S. " Albatross,'* station 2807, near tiic Galapagos Islands, in 812 fathoms, 

 ooze, bottom temperature 38°.4 F. U. S. N. Mus. 92,533. 



Pleurotomella (Pleurotomella) parella Dall, n. ep. 



Plate 14, figure 4. 



Shell large, thin, elongate-fusiform, wliite with a very thin translucent perios- 

 tracum, and about eight whorls exclusive of the (h)st) nucleus; spire rather 

 acute ; suture slightly a])prcsscd, whorl in front of it polished and slightly con- 

 stricted; margin of the whorl licrc and tlicre obscurely plicate by the incremental 

 lines ; surface of the fasciole here and there marked by obscure, irregular, short, 

 oblique, fiuc ridges nt right angles to the lines of growth ; in front of the fasciole 

 are (on tlic; penultimate whorl fourteen) low, feeble, protract ivcly oblique ribs, with 

 much wider shallow interspaces, hardly reaching the suture in frout on the spire 



