MUSEUM OF COMPARATIVE ZOOLOGY. 331 



adult to have lost the peripheral keel on the last whorl. I have never seen an 

 adult of the var. ceglees, though my specimens are much larger than Miss 

 Bush's types. The greater size of N. splendidula probably entitles it to spe- 

 cific distinction, at least until the adult extreme of N. interrupta is known. 

 The transverse engraving is present on all, though varying with individuals as 

 to strength; the section Volusia of Adams does not therefore seem required for 

 iV. imbricata, which differs only by the extent to which these are emphasized. 



A fine Niso, which seems to differ from N. splendidula only in being slightly 

 wider, and in having more numerous whorls near the apex in the length, is 

 found in the Caloosahatchie Pliocene of Florida. Without the nuclear whorls, 

 and perhaps one or two post-nuclear ones, the fossil has 14 whorls, with a length 

 of 31 and a breadth of 13 mm. The markings, so far as visible, indicate a 

 pattern like that of splendidula ; the last whorl has no keel on the periphery, 

 and the umbilical funnel seems a little wider proportionally than in N. splen- 

 didula. This shell, which is doubtless the ancestor of the last mentioned 

 species, is not rare in the Caloosahatchie beds, and may be called N. Willcox- 

 iana after Mr. Joseph Willeox of Philadelphia, who assisted me in the most 

 cordial manner to investigate that fossil fauna. 



Family PYRAMIDELLIDiE. 



Genus PYRAMIDELLA Lamarck. 



Section LONGCH^EUS Morch. 



Shell elongated, with a peripheral sulcus and the umbilicus closed or nearly 

 closed, a distinct notch in the aperture anteriorly, which is followed by a well 

 marked fasciole bounding the umbilical chink. 



The species of this group have, in my opinion, been inconsiderately lumped 

 together by Mr. Tryon in his Manual of 1886. 



Pyramidella crenulata Holmes. 



Obeliscus arenosa Tuoiney & Holmes, Pliocene Foss. S. C, p. 12G, p. p. 1857, not 



of Conrad. 

 Obeliscus cremdatus Holmes, Post PI. Foss., p. 88, pi. xiii. figs. 14, 14 a, 1859. 

 Pyramidella alveata Conrad, Silliman's Am. Journ. Sci., 2d ser., II. p. 398, 1846. 



(Tampa Bay, not described.) 

 Obeliscus floridauus Morch, Malak. Blatt,, 1875, p. 158. 

 Syrnola pulchella var. ? Morch, Malak. Blatt., 1875, p. 159, probably. 

 Pyramidella tessellata Adams (fide Poey), Arango, Malac. Cubana, p. 161, 1880; 



not of Adams. 

 Obeliscus tesselatus Dall, Hemphill's Shells, Proc. U. S. Nat. Mus., 1883, p. 330; not 



of Adams. 

 Pyramidella conica Tryon, Man., VIII. p. 302, 1886 ; not of C. B. Adams. 

 Pyramidella hastata Tryon, op. cit., p. 302 ; not of A. Adams. 



