194 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



Family ASTARTIDAE. 

 Genus DIGITARIA Wood. 



DIGITARIA AFRICANA, new species. 

 Plate 45, fig. 4; plate 54, fig. 9. 



Shell oval, bluish white. Umbones almost at the anterior end. 

 Surface marked with moderately strong lines of growth and numerous, 

 feebly expressed, radiating riblets which are about as wide as the 

 spaces that separate them. In addition to this sculpture, the sur- 

 face is marked by rather regularly spaced, strongly incised grooves, 

 which pass obliquely across the lines of growth, bending upward 

 toward the lunule and posteriorly toward the hinge line. The latter 

 ones, however, terminate at the posterior ventral margin. The 

 external sculpture is shown on the inner surface. Ventral border 

 finely denticulated. The hinge is shown in our detailed figure. 



Cat. No. 187184, U.S.N.M., contains the type, which comes from 

 Port Alfred (Coll. No. 735). This is a left valve, and measures: 

 Altitude, 3 mm.; length, 3.7 mm. 



The hinge in the type, when compared with Digitaria digitaria 

 Linnaeus, appears reversed; that is, our left valve corresponds with 

 the armature of the right valve of that species. 



Family CHAMIDAE. 

 Genus CHAMA Bruguiere. 



CHAMA GRYPHINA Lamarck (?). 



Cat. No. 250994, U.S.N.M., contains a rather poor specimen, from 

 Port Alfred, which may be this species (Coll. No. 1511). 



Family LUCINIDAE. 

 Genus LUCINA Bruguiere. 



LUCINA GLOBOSA Forskal. 



Cat. No. 98235, U.S.N.M., one valve collected by Dr. Holub, from 

 Swartkop River, South Africa. Cat. No. 186964, U.S.N.M., two 

 valves from Port Alfred (Coll. No. 335). Cat. No. 251020, U.S.N.M., 

 an additional valve from the same place (Coll. No. 1537). 



Genus LORIPES Poli. 



LORIPES CLAUSUS Philippi. 



Cat. No. 186961, U.S.N.M., one specimen from Port Alfred (Coll. 



No. 332). 



Genus PHACOIDES Blainville. 



PHACOIDES VALIDA Smith. 



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

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

 186963, two specimens (Coll. No. 334); Cat. No. 187187, two valves 

 (Coll. No. 738); Cat. No. 227818, one specimen (Coll. No. 913). 



