132 Marine Shells of the Western Coast of Florida 



on scallop shells, margins indented when some obstacle to lateral 

 growth is encountered. 



Its depth range appears to be considerable. 



Crepidula acnleato^si (Gmelin) PI. 25, figs. 175a, b 



Length, 20-30 mm. Shell with general characters of other 



Crepidulas; outer surface with irregular, radiate, tuberculate or spiny 



ribs; color brown or brownish; interior polished, brown and white, 



diaphragm white. 



From one to seven fathoms. 



Family TRUJfCATELLLDAE 



The mollusks of this family generally make their habitats about 

 the shores of warm and temperate seas. They are able to remain 

 for many days out of water and some species have become almost 

 terrestrial. 



Genus TRUNCATELLA Risso, 1826 

 Truncatella pulchella^ss Pfeiffer PI. 25, fig. 176 



Alt., 7 mm. Shell cylindrical, slightly narrowed toward trun- 

 cate apex; pale-amber color with transparent epidermis; about four 

 flattened convex whorls, axially ribbed, ribs strongest near the im- 

 pressed sutures; body whorls slightly carinate below; aperture oval, 

 a little oblique; outer lip reflected; columellar lip thickened; oper- 

 culum corneous, pale brown. 



Abundant on weedy bottoms of littoral regions; often found 

 beneath logs or stones. 



Family KISSOOIDAE 



The Rissoinidae is a family of small marine mollusks native to 

 warm and temperate seas and to moderate depths. 



Genus RISSOINA d'Orbigny, 1840 

 Rissoina bryerea2S6 (Montagu) PI. 25, fig. 177 



Alt., 5-5.5 mm. Small, rather thick, fusiform shells; white or 



^•''* Lat., aculealus, from acus, needle. 



'^^ Lat, truncatus, truncated, cut off; pulchella, very pretty, 

 -^o Dim. of Rissoa, genus dedicated to the naturalist Risso; Lat., bryon, 

 moss. 



