SOUTH AFRICAN MARINE MOLLUSKS. 203 



Genus TIVELA Link. 



TIVELA COMPRESSA Sowerby. 



Cat. No. 19835, U.S.N.M., one specimen collected by William 

 Stimpson on the North Pacific Exploring Expedition at Simons Bay. 

 Cat. No. 186938, U.S.N.M., three valves from Port Alfred (Coll. No. 

 308). 



TIVELA ALUCINANS Sowerby. 



Cat. No. 43179, U.S.N.M., one specimen from the Cape of Good 

 Hope. 



Genus SUNETTA Link. 



SUNETTA OVALIS Sowerby. 



Cat. No. 186940, U.S.N.M., seven valves from Port Alfred (Coll. 

 No. 310). 



Genus CIRCE Schumacher. 



CIRCE ALFREDENSIS, new species. 

 Plate 46, figs. 3, 4. 



Shell oval, white or pale brown flecked with rust brown. Umbones 

 about one-third of the length of the shell posterior to the anterior 

 margin. Surface marked by strong radiating ribs which increase 

 in strength from the umbones toward the ventral margin. On the 

 posterior and anterior margins they become divaricate. There are 

 30 of these ribs on the valve. The spaces separating these radiating 

 ribs are a little less in width than the ribs, and are marked with con- 

 centric riblets. These riblets extend up on the sides of the ribs but 

 do not seem to cross their summits. The character of the hinge 

 is shown in our detailed sketch. 



The type and another valve, Cat. No. 189441, U.S.N.M., come from 

 Port Alfred (Coll. No. 311). The type measures: Altitude, 11.5 mm.; 

 length, 16 mm. 



Genus CHIONE Muhlfeld. 



CHIONE, species? 



Cat. No. 187180, U.S.N.M., two valves, young specimens of a 

 species of this genus, too poor to be specifically determined, from Port 

 Alfred (Coll. No. 731). 



Genus ANOMALOCARDIA Schumacher. 



ANOMALOCARDIA ALFREDENSIS, new species. 

 Plate 44, figs. 3, 4. 



Shell inflated, heavy, irregularly triangular, flesh colored marked 

 with radiating, zigzag lines of rust brown. Outer surface polished, 

 marked by concentric lines of growth and somewhat crinkly, radiating 

 striations. The character of the hinge is shown in our detailed 

 sketch. 



