SOUTH AFRICAN MARINE MOLLUSKS. 153 



specimens (Coll. No. 1362); Cat. No. 250490, four specimens (Coll. 

 No. 1363); Cat. No. 250492, four young specimens (Coll. No. 1365); 

 Cat. No. 250493, one specimen (Coll. No. 1366); Cat. No. 250494, 

 one specimen (Coll. No. 1367); Cat. No. 250496, four young speci- 

 mens (Coll. No. 1369). 



OXYSTELE TABULARIS Krauss. 



Cat. No. 113a, U.S.N.M., one specimen collected by William Stimp- 

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

 Hope. Cat. No. 31697, U.S.N.M., five specimens from the Cape of 

 Good Hope. Cat. No. 98009, U.S.N.M., five specimens from Kas- 

 souga, South Africa. Cat. No. 186879, U.S.N.M., three specimens 

 from Port Alfred (Coll. No. 249). 



Genus UMBONIUM Link. 

 UMBONIUM VESTIARIUM Linnaeus. 



Cat. No. 59857, U.S.N.M., contains twelve specimens from the 

 Cape of Good Hope. 



Genus GIBBULA Risso. 



GIBBULA LOCULOSA Gould. 



Plate 23,figs. 1, 2, 3. 



Gibbula loculosa Gould, Proc. Bost. Soc. Nat. Hist., vol. 8, p. 21, 1861. 



Shell helicoid, light brown, with three large white spots between 

 the suture and the periphery of each whorl, dividing the whorl into 

 equal areas. There are also small spots darker than the general 

 coloration which are especially apparent on the strong spiral cords 

 which they divide into equal alternating light and dark areas. These 

 small markings give the base a checker-board appearance. Nuclear 

 whorls small, well rounded, the first smooth, the second provided with 

 four feeble spiral threads. Postnuclear whorls marked by strong 

 sublamellar spiral keels, of which four occur upon the first, and five 

 upon the second. On the next turn an intercalated cord occurs 

 between all the strong keels excepting the space between the third 

 and fourth which has two. On the last turn two cords occur between 

 the first and second keels, one between the second and third, three 

 between the third and fourth and fourth and fifth. In addition to 

 the spiral sculpture the whorJs are marked on the spire by numerous 

 closely spaced, decidedly retractively slanting, thin, lamellar, axial 

 riblets. Suture strongly impressed. Periphery rendered strongly 

 angulated by a spiral keel, between which and the first supraperiph- 

 eral keel two slender cords are presented. Base well rounded, nar- 

 rowly umbilicated, marked by a series of more or less regularly alter- 

 nating strong and less strong spiral cords of which there are twenty- 



