70 Marine Shells of the Western Coast of Florida 



ribbing. There are three diverging cardinal teeth in each valve, with 

 variable lateral teeth, and duplex muscular impressions. They are 

 solid, porcelanous in texture, sometimes heavy. 



Some of the smallest and some of the largest bivalves belong 

 to this family. 



Genus DOSINIA Scopoli, 1777 



Subgenus DOSINIDIA Ball, 1902 



Dosinia"^! eleg-ans (Conrad) PI. 13, fig. 77 



Alt., 63; length, 72 mm. Shell orbicular, flattened, ivory color; 

 transparent, brownish periostracum; promment umbos, curved for- 

 ward; small lunule; sculpture of regular, alternating ribs and grooves; 

 hinge margin thick, ligament partly submarginal; cardmal and lateral 

 teeth present; pallial sinus oblique and angulate; margins smooth. 



Dosinia discus (Reeve) is occasionally found north of Tampa 

 and may be distinguished from D. elegans by its finer and closer 

 concentric striation and its more compressed form. 



Genus TRAIVSENELLA Dall, 1883 

 Transenellaio^ conradiaiia Dall PL 13, fig. 78 



Alt., 9; length, 17; diam., 4.5 mm. Shell small, smooth, round- 

 ed rostrate and extended at posterior end. White with fine zigzag 

 markings of pale brown, often purple at posterior end; thin perios- 

 tracum; lunule well defined, escutcheon obscure. Three cardinal 

 teeth in each valve, middle right tooth bifid; one left posterior 

 lateral tooth with opposite socket in right valve; interior polished, 

 white, washed with yellow or pink, purple at posterior end; pallial 

 sinus oblique with rounded extremity. 



Characteristic of the genus Transenella is a series of grooves on 

 inner aspect of the slightly bevelled valve margins. These grooves 

 cut diagonally across the line of growth and may be best observed 

 with magnifying lens. 



Transenella cubaniana (d'Orblgny) PI. 13, fig. 79 



Alt., 8.5; length, 11; diam., 4.5 mm. Shell pure white, rarely 

 flecked with brown; trigonal, less rostrate than T. conradiaiw. Sculp- 

 ture of fine impressed, concentric lines; inner margin obliquely 

 engraved. 



^°^ N. Lat., dosin, a species of Senegal, Africa. 

 10- Lat., transcnnac, net, lattice. 



