SOUTH AFRICAN MARINE MOLLUSKS. 193 



Cat. No. 98038, U.S.N.M., four specimens from Albany. Cat. No, 

 186927, U.S.N.M., two specimens from Port Alfred (Coll. No. 297). 

 Cat. No. 227817, U.S.N.M., two specimens from the same locality 

 (Coll. No. 912). 



Genus MIODONTISCUS Dall. 



MIODONTISCUS MINIMUS Smith. 



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

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

 186932, four and one-half specimens (Coll. No. 302) ; Cat. No. 249856, 

 our valves (Coll. No. 1128); Cat. No. 249857, four valves (Coll. No. 

 1129); Cat. No. 251008, two valves (Coll. No. 1525). 



Family CONDYLOCARDIIDAE. 



Genus CONDYLOCARDIA Smith. 



CONDYLOCARDIA IO, new species. 



Plate 48, fig. 1; plate 54, figs. 7, 8. 



Shell irregularly oval, rather inflated, thin, semitranslucent. 

 Prodissoconch forming a conspicuous shield having an elevated 

 mammilate area at its apex, separated from the succeeding portion 

 of the shell by a strongly raised ridge. Succeeding portion of the 

 shell marked by very fine concentric threads which become slightly 

 stronger as the shell attains maturity. The character of the hinge 

 is shown by the detailed sketch. 



Cat. No. 251066, U.S.N.M., contains two specimens of this species 

 from Port Alfred (Coll. No. 1583). The type measures: Altitude, 

 2.3 mm.; length, 2.6 mm. 



Genus CARDITELLA Smith. 

 CARDITELLA RUGOSA Sowerby. 



Cat. No. 186928, U.S.N.M., three specimens from Port Alfred 

 (Coll. No. 298). 



Genus CARDITOPSIS Smith. 



CARDITOPSIS ALFREDENSIS, new species. 



Plate 48, fig. 4; plate 54, figs. 3, 4. 



Shell minute, subtrigonal, rather thick, bluish white, marked by 

 feebly impressed lines of growth, and very weak, low, radiating 

 threads. Edge of the shell thick all around. Basal margin weakly 

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

 sketch. 



The type and another valve, Cat. No. 251005, U.S.N.M., come from 

 Port Alfred (Coll. No. 1522). The type measures: Altitude, 2 mm.; 

 length, 1.7 mm. 



