208 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



DONAX SORDIDUS Hanley. 



Cat. No. 186957, U.S.N.M., one and one-half specimens from Port 

 Alfred (Coll. No. 327). 



DONAX BIPARTITUS Pilsbry. 



Cat. No. 160861, U.S.N.M., one specimen from South Africa. 



DONAX SIMPLEX Sowerby. 



There are three lots of this species in the collection of the United 

 States National Museum, all from Port Alfred, as follows: Cat. No. 

 187176, one specimen (Coll. No. 725); Cat. No. 251027, one valve 

 (Coll. No. 1544); Cat. No. 251034, one specimen and one valve (Coll. 

 No. 1551). 



DONAX BURNUPI Sowerby. 



Cat. No. 187175, U.S.N.M., one valve from Port Alfred (Coll. No. 

 724). Cat. No. 251028, U.S.N.M., one valve (Coll. No. 1545). Cat. 

 No. 251036, U.S.N.M., one valve (Coll. No. 1553). 



Family SOLENIDAE. 



Genus SOLEN Linnaeus. 



SOLEN ALFREDENSIS, new species. 

 Plate 40, figs. 1,2. 



Shell subcylindric, laterally compressed, gaping anteriorly and 

 posteriorly, obliquely truncated anteriorly, well rounded posteriorly. 

 The valves have a very strong constriction immediately posterior to 

 the anterior margin. They are marked with fine lines of growth 

 only. 



The type and another specimen, Cat. No. 227816, U.S.N.M., come 

 from Port Alfred (Coll. No. 911). The type measures: Altitude, 15 

 mm.; length, 96.5 mm.; diameter, 11 mm. 



SOLEN CAPENSIS Fischer. 



There are three lots of this species in the collection of the United 

 States National Museum, all from Port Alfred, as follows: Cat. No. 

 186960, one specimen (Coll. No. 330) ; Cat. No. 249858, three speci- 

 mens (Coll. No. 1130); Cat. No. 251021, two young specimens (Coll. 

 No. 1538). 



Family MACTRIDAE. 



Genus SCHIZODESMA Gray. 

 SCHIZODESMA SPENGLERI Linnaeus. 



Cat. No. 86, U.S.N.M., one specimen collected by William Stimp- 

 son on the North Pacific Exploring Expedition at False Bay, Cape of 



