SOUTH AFRICAN MARINE MOLLUSKS. 179 



mens (Coll. No. 1484); Cat. No. 250612, one specimen (Coll. No. 

 1485); Cat No. 250613, one specimen (Coll. No. 1486); Cat. No. 

 250614, three specimens (Coll. No. 1487); Cat. No. 250615, two 

 specimens (Coll. No. 1488); Cat. No. 250616, one specimen (Coll. No. 

 1489); Cat. No. 250617, one specimen (Coll. No. 1490); Cat. No. 

 250618, two specimens (Coll. No. 1491); Cat. No. 250619, one speci- 

 men (Coll. No. 1492) ; Cat. No. 250620, one specimen (Coll. No. 1493) ; 

 Cat. No. 250621, one specimen (Coll. No. 1494). 



ISCHNOCmTON TIGRINUS Krauss. 



Cat. No. 177, U.S.N.M., contains a specimen collected by William 

 Stimpson on the North Pacific Exploring Expedition on the Cape of 

 Good Hope. Cat. No. 110252, U.S.N.M., contains three specimens 

 from the same place. In addition to these, there are four lots in the 

 collection of the United States National Museum from Port Alfred, 

 as follows: Cat. No. 249818, one specimen (Coll. No. 1090); Cat. No. 

 250604, one specimen (Coll. No. 1477) ; Cat. No. 250607, one speci- 

 men (Coll. No. 1480); Cat No. 250624, one specimen (Coll. No. 1497). 



Genus DINOPLAX Carpenter. 



DINOPLAX GIGAS Gmelin. 



Cat. No. 110201, U.S.N.M., one specimen from the Cape of Good 

 Hope. In addition to this, the United States National Museum has 

 seven lots from Port Alfred, as follows: Cat. No. 186908, two valves 

 (Coll. No. 278); Cat. No. 229832, one specimen (Coll. No. 1104); 

 Cat. No. 249829, four specimens (Coll. No. 1101); Cat No. 249830, 

 two complete specimens (Coll. No. 1102); Cat. No. 250600, one speci- 

 men (Coll. No. 1473); Cat. No. 250601, one specimen (Coll. No. 1474); 

 Cat. No. 250602, one specimen (Coll. No. 1475). 



DINOPLAX GIGAS ALFREDENSIS, new subspecies. 

 Plate 39, figs. 1, 2. 



Shell similar to Dinoplax gigas in outline and coloring, but with the 

 sculpture in every way much finer. Radiating lines of the lateral 

 areas and the anterior plate only very feebly expressed, with the 

 central very finely truncate as compared with D. gigas. 



The type, Cat. No. 249831, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1103); it measures: Length, 62 mm.; diameter, 22 mm. 

 Another specimen is registered as 249820, U.S.N.M., and comes from 

 the same locality (Coll. No. 1092). 



DINOPLAX FOSSUS Sykes. 



Cat. No. 249823, U.S.N.M., contains a young specimen from Port 

 Alfred (Coll. No. 1095). 



