MUSEUM OF COMPAKATIVE ZOOLOGY. 325 



TTaliitat. Barbados, in 100 fins. 



Tliis shell has a (lidcrcnt aspect from the European species, but when the 

 dilVerences are formulated, us above, they do not sound very important. I 

 presume it to be distinct. 



Aclis egregia n. s. 



Plato XVIII. Fie 12. 



Shell thin, not polished, whitish, rather acute, eleven-whorled ; whorls 

 neatly rounded, with distinct but not open or channelled sutures; nucleus 

 smooth, translucent, a little pinched or turned up; the first three or four whorLs 

 nearly smooth, the next two or three with about twenty somewhat irregular 

 costac which are more prominent posteriorly; the subsequent whorls are nearly 

 smooth, except for rather coarse lines of growth, with occasional faint indica- 

 tions of costai; spiral sculpture none or very little; aperture pointed behind, 

 somewhat produced in front, completed by a thin callus on the body; margins 

 hardly thickened, that of the columella slightly reflected, forming a deep chink 

 but no umbilicus; without teeth, plaits, or folds of any kind. Operculum and 

 soft parts unknown. Lon. of shell, 13.0; of aperture, 4.0; max. lat. of shell, 

 4.7 mm. 



Habitat. Station 228, off" St. Vincent, in 785 fms., fine gray sand and ooze, 

 bottom temperature 39°. 5 F. Station 163, off Guadeloupe, in 769 fms., fine 

 sand, bottom temperature 39°. 75. 



This species is very large for a true Aclis, and may possibly belong to another 

 group, but agrees in all particulars with the European A. supranitida and 

 others of the group, wath which I have compared it. In the absence of the 

 soft parts, some doubt must remain on the subject. 



Aclis nucleata n. s. 



Plate XVIII. Fig. 7. 



Shell white, polished, shining, elongated, with a blunt apex and minutely 

 perforate base; whorls eleven and a half, less inflated and more uniform in size 

 than in A . egregia ; nucleus immersed, oblique, much larger than in the last 

 species ; sculpture indistinct, consisting of irregular indefinite transverse very 

 slightly elevated ridges crossed here and there by obscure spiral lines, the 

 whole only visible under a lens and giving the surface a slightly malleated as- 

 pect; suture slightly appressed, distinct, not deep; aperture much as in the 

 last species but not quite so much produced anteriorly ; pillar thin, lightly re- 

 flected part way over a very minute axial perforation; outer lip thin, sharp, 

 very little callus on the body between the posterior corners of the aperture. 

 Lon. of shell, 9.3; of aperture, 2.25; max. lat. of shell, 3.0 mm. 



Habitat. Station 230, off" St. Vincent, in 464 fms., gray ooze, bottom tem- 

 perature 41°.5 F. 



