MUSEUM OF COMPARATIVE ZOOLOGY. 319 



Scala polacia n. s. 



Plate XVIII. Fig. 10. 



Shell grayish white, thin, cylindrical with abruptly sharpened apex, twelve 

 rounded whorls and numerous slightly elevated thin sharp varices; nucleus 

 translucent, white, polished, three-whorled ; subsequent whorls spirally sculp- 

 tured with ten to twenty slightly raised extremely fine flattened threads about 

 half as wide as their interspaces, uniformly distributed over the surface and of 

 uniform size; transverse sculpture composed by the fine sharp thin reflected 

 and anteriorly convex varices, numbering about twenty-eight on the last whorl 

 and slightly marked on their concave posterior faces by the extension of the 

 spiral sculpture; whorls and base beautifully rounded ; suture distinct but not 

 deep; lip not continuous over the body; line of the varices from one whorl to 

 another in most cases continuous, over the whorl arched forward a little; aper- 

 ture nearly circular, pillar very thin and not differentiated from the rest of 

 the margin. Lon., 7.25; of last whorl, 2.5; max. lat., 2.5 mm. 



Habitat. Lat. 24° 15' K, Lon. 82° 13' W., Station 5, off Cuba, in 229 fms., 

 soft ooze, bottom temperature 49°.5 F. 



But for the regularity of the varices and the fact that they are not crenulated, 

 this lovely little species might be referred to Cirsotrema. 



Scala formosissima Jeffrets. 



Plate XVIII. Fig. 11. 



? Scalaria formosissima Jeffreys, P. Z. S. 1884, p. 140, pi. x. fig. 10. 



Shell small, thin, elongated, with a brown opaque sculptured nucleus of 

 three and a half whorls and five and a half (or more) white normal whorls; 

 imperforate, but with a chink behind the inner reflection of the peristome; the 

 later whorls rounded, but with the periphery slightly flattened, giving a faint 

 angulation to the base and posterior aspect of the whorl; the earlier turns do 

 not show this; spiral sculpture between the sutures of some 8-12 flattened 

 strong riblets, with channelled interspaces which grow wider toward the aper- 

 ture but in general are narrower than the riblets; there are also some faint 

 spiral lines; the apical turn of the nucleus is smooth and slightly asymmetri- 

 cal, proportionally rather large and inflated, the remainder of the nucleus is 

 strongly marked with flexuous riblets extending from suture to suture; the 

 later whorls are marked with very fine transverse threads, hardly visible, and 

 with thin, short, sharp, somewhat oblique, numerous crenulated or finely 

 fluted varices, partly continuous with those of the preceding whorl and partly 

 intercalary; the margins of the varices, though nowhere spinous, are slightly 

 angulated in harmony with the above mentioned faint angulation of the last 

 whorl or two ; they become obsolete on the somewhat flattened base, which is 

 marginated by a slender elevated thread proceeding from the suture; the peri- 



