SOUTH AFRICAN MARINE MOLLUSKS. 141 



on the succeeding. These riblets are about one-third as wide as the 

 spaces that separate them on the first turn, while on the last turn the 

 intercostal spaces are only a trifle wider than the riblets. The spaces 

 between the riblets are crossed by numerous, very fine spiral stria- 

 tums. Base gradually, deeply umbilicated. The umbilicus marked 

 at its outer edge by a strong carina. The entire surface of the base 

 is marked by the continuation of the axial riblets, which pass undi- 

 minished over the base, into the umbilicus. The base appears slightly 

 excavated immediately posterior to this carina. The exterior um- 

 bilical wall is concave and marked by the continuation of the axial 

 riblets from aperture; outer lip thickened at the edge; inner lip sin- 

 uous, slightly reflected, and continuing over the parietal wall, ren- 

 dering the peritreme complete. 



The type, Cat. No. 249769, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1041). It measures: Altitude, 3 mm. The greatest meas- 

 urement obtainable while lying on the aperture is 3 mm. Another 

 specimen, Cat. No. 250534, U.S.N .M. (Coll. No. 1407), comes from 

 the same place. 



Family ACMAEIDAE. 



Genus ACMAEA Eschscholtz. 



ACMAEA ROSEORADIATA Smith. 



Cat. No. 19319, U.S.N.M., one specimen from the Cape of Good 

 Hope. Cat. No. 187133, U.S.N.M., two specimens from Port Alfred 

 (Coll. No. 679). Cat. No. 250573, U.S.N.M., contains another speci- 

 men from the same locality (Coll. No. 1446). 



Family PATELLIDAE. 



Genus PATELLA Linnaeus. 



PATELLA GRANATIN A Linnaeus. 



The United States National Museum contains eight lots of this 

 species from the Cape of Good Hope, as follows: Cat. No. 7586, four 

 specimens collected by William Stimpson on the North Pacific Ex- 

 ploring Expedition; Cat. No. 7587, ten specimens; Cat. No. 16615, 

 two specimens ; Cat. No. 17347, two specimens; Cat. No. 89797, three 

 specimens; Cat. No. 89798, one specimen; Cat. No. 103886, four 

 specimens; Cat. No. 128388, two specimens. Cat. No. 184355, 

 U.S.N.M., one specimen from Cape Town. Cat, No. 186902, U.S.N.M. 

 one specimen from Port Alfred (Coll. No. 272). 



PATELLA LONGICOSTA Lamarck. 



Cat. No. 109, U.S.N.M., two specimens collected by William Stimp- 

 son on the North Pacific Exploring Expedition at the Cape of Good 

 Hope. Cat. No. 89835, U.S.N.M., two specimens from the Cape of 

 Good Hope. Cat. No. 186901, U.S.N.M., three specimens from Port 



