28 BULLETIN 90, UNITED STATES NATIONAL MUSEUM. 



faintly axialiy striated by incremental lines, except the last, where 

 the sculpture gradually assumes the form of fine, somewhat acute, 

 retractive, equally spaced, elevated, threadlike lines of growth, with 

 about equal interspaces covering the whorl; last whorl attenuated 

 in front, with a relatively rather large umbilical perforation; aper- 

 ture elongate-ovate, the peritreme slightly reflected, widest over the 

 umbilicus, the outer lip slightly compressed behind the middle; 

 pillar simple, smooth ; body with a rather thick layer of enamel con- 

 necting the inner and outer lips of the shell, with a somewhat feeble 

 subsutural nodule separated from the posterior end of the outer lip 

 by a slight but perceptible sulcus. Height 9.2, maximum diameter 

 4 mm. 



'i'ampa silex beds, Ballast Point, Tampa Ba}'^, Florida. 



Type from the Post collection, U. S. Nat. Mus. No. 165014. 



Family CEKIONIDAE. 



Genus CERION Bolten. 



Cerion Bolten, Mus. Boltenianum, p. 90, 1798. First species, Turbo uva 



Gmelin. Curagao. 

 Strophia Albers, Heliceeu, zvveite ausg., Nov., ISGO, p. 299. Type, Pupa 



mumia Bruguiere. Cuba. 



Section EOSTROPHIA Ball. 



Eostrophia Dall, Trans. Wagner Inst., vol. 3, pt. 1, p. 12, 1890. 



Shell without gular laminae or callosities. Type, /Strophia ano- 

 donta Dall. 



CERION (EOSTROPHIA) ANODONTA Dall. 



Plate 1. fig. 15. 



Strophia (Eostrophia) anodonta Dall, Trans. Wagner Inst., vol. 3, pt. 1, 

 p. 13, pi. 1, figs. 8e, 8d, Aug., 1890. 



Tampa silex beds at Ballast Point; Shepard, Newman, Dall, and 

 Burns; at Old Tampa bay, shore; Burns. U. S. Nat. Mus. No. 

 165016. 



CERION ANODONTA var. FLORIDANUM Dall. 



Plate 3, fig. 4. 



strophia (anodonta var. ?) floridana Dall, Trans. Wagner Inst, vol. 3, 

 pt. 1, p. 13, pi. 1, fig. 6, Aug., 1890. 



Tampa silex beds at Ballast Point, Tampa Bay, Florida, Dall. 

 U. S. Nat. Mus. No. 111975. 



This has the same number of whorls as the typical form, but is 

 shorter and stouter, with a relatively larger aperture. 



