I 



MUSEUM OF COMPARATIVE ZOOLOGY. 331 



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

 adult of llie var. (('(/Ires, thou<,'h my 8p(;ciineiiH are much larger than Mis.s 

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

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

 Tile transverse engraving is present on all, thougli varying with individuals as 

 to strength; the section Volusia of Adams does not therefore seem re(piired for 

 N. inibricafa, which differs only by the extent to wdiich these are emphasized. 



A fme iV/.s-o, which seems to differ from N. splendidula only in being slightly 

 wider, and in having more numerous whorls near tlie apex in the l(;ngth, is 

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

 and perhaps one or two post-nuclear ones, the fossil has 14 whoils, 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 Willcox of Philadelphia, who assisted me in the most 

 cordial manner to investigate that fossil fauna. 



Family PYRAMIDELLID^. 



Genus PYRAMIDELLA Lamarck. 



Section LONGCH^US 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. Try on in his Manual of 1886. 



Pyramidella crenulata Holmes. 



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



of Conrad. 

 Obeliscus crenulatus Holmes, Post Pi. Foss., p. 88, pi. xiii. figs. 14, 14 a, 1859. 

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



(Tampa Bay, not described.) 

 Obeliscus Jloridanus Morch, Malak.' Blatt., 1875, p. 158. 

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

 Pt/ramidella tessellata Adams {Jide Poey), Aran^o, 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. 



