no. 1829. M0LLU8K8 OF THE GENUS ACLIS— BARTSCH. 437 



Sutures very strongly constricted. Periphery of the last whorl and 

 the moderately long base well rounded, marked like the spire. 

 Aperture with the posterior angle obtuse (outer lip fractured; ante- 

 rior portion of the columella lost); parietal whorl covered with a 

 moderately thick callus which joins the columella with the posterior 

 angle of the aperture. 



The type (Cat. No. 82973a, U.S.N.M.) was dredged by Doctor Rush 

 in 150 to 200 fathoms, off Fowey Rocks, in Florida Straits. It has 

 eight whorls and measures: Length 2.9 mm. (if the aperture were 

 complete the shell would probably measure 3 mm.), diameter 1 mm. 

 This form is nearest related to A. hermudensis Dall and Bartsch, but 

 can be separated from it at once by its much greater size as well as 

 detail sculpture. 



ACLIS BERMUDENSIS Dall and Bartsch. 



Plate 59, fig. 4. 



Aclis hermudensis Dall and Bartsch, Proc. U. S. Nat. Mus., vol. 40, 1911, p. 278. 



A figure of this species, which has been already described, is added 

 for purposes of comparison. 



ACLIS VERRILLI, new species. 

 Plate 59, fig. 6. 



Shell acicular, yellowish-white. Nuclear whorls four, well-rounded, 

 with strongly impressed sutures, smooth, forming a slender apex to 

 the spire. Post-nuclear whorls well-rounded, appressed at the 

 summit, sculptured by six feeble, poorly denned, somewhat irregular 

 spiral threads and numerous incremental lines, the combination of 

 the two lending the surface of the spire a feebly malleated sur- 

 face. In addition to the above sculpture the surface is marked with 

 irregularly disposed varical lines. Sutures strongly impressed. 

 Periphery of the last whorl well rounded. Base moderately long, 

 well rounded, narrowly umbilicated, marked by seven feeble and 

 irregularly placed spiral lines, its surface having the same aspect 

 as that of the spire. Aperture rather large; somewhat effuse ante- 

 riorly, posterior angle somewhat obtuse; outer lip patulous, columella 

 oblique, slightly curved and strongly revolute. 



The type (Cat. No. 44811, U.S.N.M.) has eleven whorls and meas- 

 ures: Length 4.6 mm., diameter 1.7 mm. It was dredged by the 

 U. S. S. Fish Hawk at station 894 in 365 fathoms, bottom tem- 

 perature 40°, off Marthas Vineyard, Mass. One specimen (Cat. 

 No. 44808, U.S.N.M.) from U. S. S. Fish Hawk station 892, 

 487 fathoms, off Marthas Vineyard. One specimen (Cat. No. 44809, 

 U.S.N.M.) from station 1093, 349 fathoms, bottom temperature 40°, 

 off Marthas Vineyard. Two specimens (Cat. No. 78161, U.S.N.M.) 

 from station 2710, 984 fathoms, southeast of Nantucket. One speci- 



