SOUTH AFRICAN MARINE MOLLUSKS. 157 



ture subcircular, oblique; outer lip thin at the edge where it is ren- 

 dered sinuous by the strong spiral cords ; columella moderately stout, 

 well curved ; parietal wall covered with a thin callus. 



Gould's cotypes, two specimens, Cat. No. 222a, U.S.N.M., were 

 collected by William Stimpson on the North Pacific Exploring Expedi- 

 tion at False Bay, Cape of Good Hope. The largest of these, the 

 specimen figured, has almost four postnuclear whorls, and measures: 

 Altitude, 5.6 mm.; greater diameter, 5.7 mm.; lesser diameter, 5 mm. 

 Cat. No. 187110, U.S.N.M., one specimen from Port Alfred (Coll. No. 

 656). 



GIBBULA THALIA, new species. 

 Plate 30, fige. 1, 2, 3. 



Shell small, white, flaked with large patches of brown, sprinkled 

 irregularly with blotches of carmine. Nuclear whorls two and one- 

 half, well rounded, smooth. Postnuclear whorls strongly rounded, 

 marked with five strong, equal, spiral keels between the sutures, of 

 which the first is at the summit, while the last forms the peripheral 

 keel. The spaces between the spiral keels are a little wider than the 

 keels. In addition to the spiral sculpture the whorls are marked by 

 very numerous, decidedly retractive, axial threads. Sutures strongly 

 impressed. Base moderately long, Well rounded, strongly, openly 

 umbilicated, marked by nine, equal and equally spaced, depressed 

 spiral cords, which are almost double the width of the spaces that 

 separate them. In addition to these spiral cords the base is marked 

 by the continuations of the axial threads. Inside of umbilicus smooth. 

 Aperture subcircular, oblique; outer lip rendered decidedly sinuous 

 at the edge by the external sculpture; inner lip strongly curved and 

 slightly reflected. 



The type, Cat. No. 187112, U.S.N.M., comes from Port Alfred (Coll. 

 No. 658). It has three postnuclear whorls, and measures: Altitude, 

 4.5 mm.; greater diameter, 5.5 mm. 



GIBBULA HERA, new species. 

 Plate 26, figs. 1, 2, 3. 



Shell subglobose, very dark brown, mottled and streaked with 

 yellow horn color. Nuclear whorls two and one-half, well rounded, 

 smooth. Postnuclear whorls well rounded, decidedly shouldered at 

 the summit, marked between this and the suture by broad, depressed, 

 spiral cords, of which five occur upon the first, six upon the second, 

 while the last whorl has eight, owing to splitting of the primary 

 cords. The spaces that separate the cords are less than one-half the 

 width of the cords and are very feebly impressed. In addition to the 

 above sculpture the spire is marked with feeble, decidedly retractive 

 lines of growth which pass over the cords and grooves. Periphery 

 of the last whorl subangulated, marked by a slender spiral cord. 



