144 Marine Shells of the Western Coast of Florida 



acute; about 10 convex whorls with numerous longitudinal ribs 

 terminated at base of body whorl by a single spiral thread; aperture 

 oval; anterior canal shallow. 



Tidal flats and near low water mark. 



t'erithidea scalarifonnis-5« Say PI. 28, fig. 200 



Alt., 20-25 mm. Color light fawn, spirally banded with brown, 

 occasionally with white; spire tapering, apex usually truncated; 

 sutures well impressed, defined by narrow threads; 10 convex whorls 

 crossed by numerous, closely placed, slightly curved ribs; on body 

 whorl ribs terminate at periphery; spiral sculpture of whorls in- 

 distinct; aperture rounded, lip thickened, reflected, with flattened 

 margin; columella straight; position of anterior canal indicated by 

 a shallow notch; base with strong spiral cords. 



Common on tidal salt flats. 



Genus BITTIOI Leach in Gray, 1847 

 Bittinm varium^so (Pfeiffer) PI. 28, fig. 202 



Alt., 5-6 mm. Shell thin, grayish white or buff-colored; apex 

 acute, spire tapering; seven or eight flattened convex whorls; sutures 

 well defined; sculpture of delicate, slightly curved longitudinal 

 ribs nodulated by fine spiral grooves; aperture oval, lip not thick- 

 ened, a well-developed varix posterior to lip; anterior canal not 

 defined; base spirally grooved. 



Common in shallow water on grassy bottoms. 



B. varium gibberulum Adams is dark brown with smaller body 



whorl varicosely gibbous, and sculpture more sharply cut than in 



the typical B. variii/m. 



Meyer and Moebius have described spawn as a flat, slimy, spiral 

 coil, about 3 mm. across. Lo Bianco describes it as a white ribbon, ir- 

 regularly folded upon itself. — Marie Lebour. 



Look for this on eel grass. 



Family STR03IBTDAE 



The Strombidae constitute an interesting family of about 100 

 species distributed through warm seas, usually in shallow water. 

 Almost no other group of mollusks rivals it in the variety of form 



259 Lat., scala, ladder, staircase. 



-^° Lat., of obscure origin; varius, diverse. 



