294 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



Cancellariidae. 

 CANCELiLARIA Lamarck. 

 Type Valuta reticulata Linne. 



Narona II. and A. Adams. 



Type C. mitraeformis Sowerby, not Brocchi. 



Cancellaria (Narona) exopleura Dall, n. sp. 



Shell small, slender, acute, witli five rounded whorls, a deep suture, a pilose 

 periostracum, whitish more or less banded spirally with reddish brown ; nucleus 

 defective, but apparently glassy, bluntly pointed and with about two whorls ; 

 subsequent whorls with (on the antepenultimate whorl fourteen) narrow, sharp, 

 low riblets, with wider interspaces, becoming relatively less prominent on the later 

 whorls ; these are crossed by from four to six narrow, subequal, distant, rounded 

 spiral threads, not nodulous at the intersections ; the last whorl is also furnished 

 with two or three prominent varices, irregularly disposed, beside the terminal 

 varix; these are thick and rounded; on the last whorl there are about fifteen 

 feeble spirals and some intercalary finer threads appear ; aperture slightly shorter 

 tlian the spire, semilunate, the outer lip reflected and thickened, with 9-10 denti- 

 cles internally, not continued into the throat; inner lip not callous; pillar with 

 two strong distant plaits, the canal wide, produced and recurved ; no operculum. 

 Length of shell, 26 ; of the last whorl IS ; of the aperture, 12.5 ; max. lat. 12 mm. 



U. S. S. "Albatross," station 2804, in Panama Bay, in 47 fathoms, muddy 

 bottom. U. S. N. Mus. 96,638. Also at Payta, Peru, Dr. Jones. 



This is nearest to C. clavatula Sowerby, from the same region, which is a 

 smaller sliell, with one less whorl, with fewer ribs (ten on the antepenultimate 

 whorl), which are rounded and much more prominent; the whorls in C clavatula 

 also increase more rapidly and have a tabulate aspect. 



Cancellaria (Merica) corbicula Dall, n. sp. 



riate 1, figure 4. 



Shell small, thin, milk-white, with a thin, pale yellow periostracum, and about 

 six whorls beside the blunt (decollate) nucleus ; form bulimoid, aperture nearly 

 equal to the spire in length; whorls evenly rounded, with a strongly marked 

 suture ; sculpture between the sutures of seven to nine flattish revolving threads 

 with slightly wider channelled interspaces ; these are crossed by numerous, sub- 

 rqually spaced, very narrow, low, slightly arcuate axial ridges, sliglitly nodulous 

 at the intersections ; there are also very numerous, prominent, incremental lines 

 iu the interspaces; aperture oval, outer lip thin, smooth, entire, reflected; inner 



