346 PROCEEDINGS OF THE ACADEMY OP 



three-fifths, and the aperture about one-fourth the length of the 



shell ; mouth ovate, outer lip simple, internally ribbed, thickened 



at its upper part, turned and reflected upon the bod.y-whorl, 



forming a callus on the upper portion of the columella. 



Fig. 3. wliich latter is rather abruptly shortened and slightly 



twisted anteriorly. 



Length .16. Length of aperture .06. Breadth .06. 



Habitat. — West Coast of Florida, on the shores of 

 Tampa Bay, collected by Col. E. Jewett. Only a few 

 specimens were obtained, of which three are in my 

 cabinet. All the specimens examined by me were beach shells, 

 without opercula, consequently the generic position is somewhat 

 doubtful. This species has apparently relations with Nitidella 

 (N. cribraria or N. guttata), also with Truncaria {T.eiiryioides), 

 but as these genera at present include many incongruous species, 

 a revision is necessary before this and similar forms can be satis- 

 factorily placed. The genus Nitidella was made by Swainson 

 {vide "Treatise on Malacology," pp. 151-153-313) on the Colum- 

 bella nitida, a West Indian shell, with a sliort spire, long body- 

 whorl, and a plait on the columella, a markedly different form from 

 N. guttata or N. cribraria, which are generall}^ included with it. 

 There are numerous allied forms in this connection, which approx- 

 imate so closely that an examination of tlie opercula is indispen- 

 sable to generic determination. (Vide remarks of Mr. Dall in 

 Am. Journ. Conch., vol. vii. p. 115.) 

 Clathurella Jewetti, Stearns. 



Shell small, abbreviated fusiform, turreted, of a dull ashen-red- 

 dish color wlien dry, dark-reddish to purplish when wet; number 

 of whorls six or seven, convex and somewhat flattened 

 Fig. 4. above, sculptured with eleven or twelve prominent lon- 

 gitudinal ribs, which extend nearly or quite to the base of 

 the bod^'- whorl ; longitudinal ribs crossed by ten totwelve 

 strong thread-like lateral costre, which at the points of 

 crossing are in some specimens produced into rounded 

 nodules ; the upper whorls show three to four of the 

 lateral costse, generall}^ three ; aperture narrow, about 

 half the length of the shell, of a purplisli-black or dark-chocolate 

 color; outer lip thickened and deeply notched al)Ove ; columella 

 nearly straight, calloused ; terminal canal short. 



