138 Marine Shells of the Western Coast of Florida 



sharp, elevated, annular ribs separated by interspaces which become 

 wider toward aperture and are finely, longitudinally striate. The 

 apical septum is slightly convex with minute, laterally placed mucro. 

 Corneous operculum. 



Caeciiin oaniienensis de Folin 



Alt., 2; at summit, 3; diam. at base, .55 mm. Shell white or 

 whitish; conic, regularly increasing in diameter from summit to base; 

 slightly swollen toward aperture; aperture always contracted, margin 

 not thickened, oblique; surface with fine, delicate, transverse stria- 

 tions. The septum is characterized: claw-shaped, directed to right of 

 plane of truncation; lateral margin nearly straight; operculum.f" 



Genus MEIOCEKAS Carpenter, 1859 

 Meioeeras nituliim-*'^ (Stimpson) PI. 26, fig. 186 



Length, 2-2.5; diam. at center, .75 mm. Shell small, polished, 

 translucent, brown or brownish, arcuate, dorsal convexity great- 

 est; aperture circular, oblique, sharp-edged; apical end smaller; 

 apical plug convex; operculum corneous. 



Often found on eel grass. 



Family MODULIDAE 



Members of this family are native to warm seas. Three species 

 are recorded from Florida. 



Genus 3I0DULUS Gray, 1842 

 Moduliis-'s modulus (Linne) PL 27, fig. 187 



Alt., 12; diam. of base, 17 mm. Apex acute, spire of about 

 three small whorls, depressed; body whorl large with sloping shoul- 

 der and definite peripheral keel; color yellowish white with brown 

 markings, brownish epidermis; sculpture over upper portion of shell 

 consists of low revolving ridges and 10 radiating ribs which termin- 

 ate at peripheral keel; base has six or eight strong revolving ribs 

 separated by deep grooves which are striate by growth lines; um- 

 bilicus small, deep; aperture round below, oblique to vertical axis, 



-•'" Gr., meiosis, to make smaller; keras, horn; Lat., nit'idum, shining. 

 -■*s Lat, modulus, a measure. 



