190 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



ventrally. Basal edge somewhat sinuous. Anterior end with 16 

 radiating, low, flattened cords; posterior end with 17. 



Gould's cotypes, six specimens, Cat. No. 126, U.S.N.M., were col- 

 lected by William Stimpson on the North Pacific Exploring Expedi- 

 tion at Simon's Bay. The specimen figured measures: Length, 11.8 

 mm.; altitude, 7 mm.; diameter, 7 mm. Cat. No. 186920, U.S.N.M., 

 one specimen from Port Alfred (Coll. No. 290) . 



MODIOLARIA AFRICANA, new species. 

 Plate 41, fig. 2. 



Shell small, pale yellow. Hinge margin almost straight; posterior 

 lateral margin evenly, gradually rounded, the anterior lateral shortly, 

 strongly rounded, the basal slightly emarginate. The posterior por- 

 tion is marked by about 50 rather strong, radiating, axial riblets, while 

 the extreme anterior bears 12. In addition to the radiating sculp- 

 ture, the shell is marked by rather strong, concentric threads which 

 render the radiating riblets crenulated at their junction. The area 

 devoid of radiating sculpture is equal to about one-third of the entire 

 length of the shell at the basal margin. 



The type, Cat. No. 251000, U.S.N.M., comes from Port Alfred 

 Coll. No. 1517). It measures: Altitude, 2 mm.; length, 3.5 mm. 



MODIOLARIA IMA, new species. 

 Plate 40, figs. 4, 5. 



Shell pale green, variously mottled with brown. Dorsal margin 

 slightly curved, the posterior lateral strongly, evenly so, the anterior 

 lateral very strongly, shortly curved, the basal slightly emarginate 

 anteriorly. The posterior portion of the shell is marked by 16, broad, 

 low, rounded, radiating riblets, which become narrower and closer 

 spaced toward the dorsal margin. The anterior end is marked by 

 4, weak, radiating riblets. In addition to the radiating sculpture, the 

 shell is marked by irregular incremental lines, which pass over the 

 radiating sculpture as fine threads, but do not render them crenu- 

 lated. The area devoid of radiating sculpture is equal to about two- 

 fifths of the length of the shell at the ventral border. 



The type and another valve, Cat. No. 249848, U.S.N .M., come from 

 Port Alfred (Coll. No. 1120). The type measures: Altitude, 4 mm.; 

 length, 7 mm. 



Order ANOMALODESMACBA. 



Family SOLEMYIDAE. 

 Genus SOLEMYA Lamarck. 



SOLEMYA, species? 



Cat. No. 250996, U.S.N.M., contains fragments of a young speci- 

 men too poor to be determined, from Port Alfred (Coll. No. 1513). 



