Cerithiidae 143 



The animal has a white foot, body mottled black and white, 

 black eyes surrounded by white circles and placed a little behind 

 bases of the tentacles. 



Shallow water beyond low tide mark. Often about oyster bars. 



Genus BATILLAKIA Benson, 1842 

 Batillaria minima-ss (Gmelin) PI. 27, fig. 196 



Alt., 13 mm. Shell rather stout and rotund, black, ashen or 

 bluish gray, sometimes ferruginous — often with dark or light sutural 

 bands; six to eight whorls sculptured with low longitudinal ribs 

 unequally nodulated by spiral ridges; fine spiral threads in inter- 

 spaces; aperture oval, lip sharp; anterior of aperture dark-colored; 

 basal canal sharply deflected to left. 



B. minima nigrescens (Menke) is the specific name given to the 

 black, unicolored type. 



Common and abundant between tide marks. 



Batillaria minima septemstriata-"*' (Say) PI. 27, fig. 197 



Alt., 12 or 13 mm. Shell a little more slender with B. -minima, 



similar in general characters; dark-colored with white sutural band; 



longitudinal ribs nodulated by elevated spirals; longitudinal ribs 



sometimes bifid over base of body whorl. 

 Found with B. m^inima. 



Genus CERITHIDEA Swainson, 1840 

 Cerlthidea costatass^ (da Costa) PI. 28, fig. 199 



Alt., 12-15 mm. Shell brown, darker band below sutures; spire 

 turreted, apex acute; nine or ten convex whorls; sutures distinct, 

 marked by spiral threads; about 15 curved, longitudinal ribs over 

 each whorl, not continuous across sutures; aperture oval, notched or 

 channeled at base. 



Shallow, brackish water. Tidal salt flats. 



Cerithidea costata turrita^^s Stearns PI. 28, fig. 201 



Alt., 10-12 mm. Shell pale fawn color with lighter band about 



periphery of whorls, periostracum rather thick; spire turreted, apex 



2^5 Lat., minimus, the least. 



2S6 Lat., septem, seven; striatus, striped. 



-^^ Lat., costatus, from costa, rib. 



-5s Lat., turris, tower. 



