SOUTH AFRICAN MARINE MOLLUSKS. 159 



bands which have the same arrangement as the spiral sculpture on 

 the spire. The umbilicus is without any sculpture. Entire surface 

 of spire and base marked by exceedingly fine lines of growth which are 

 decidedly retractively slanted on the spire. Aperture subquadrate, 

 decidedly oblique; outer and basal lips forming an obtuse angle at 

 their junction; inner lip thick, decidedly sinuous; parietal wall 

 glazed with a thin callus. 



The type, Cat. No. 102730, U.S.N.M., comes from the Cape of Good 

 Hope. It has four postnuclear whorls, and measures: Altitude, 

 6 mm.; greater diameter, 6.4 mm. Cat. No. 43011a, U.S.N.M., con- 

 tains one specimen from the Cape of Good Hope. 



GIBBULA MEDUSA, new species. 

 Plate 29, figs. 7, 8, 9. 



Shell depressed conic. Nuclear whorls white. Postnuclear whorls 

 marked with broad axial bands of brown which ma} T extend 

 entirely across the whorls, or may be interrupted in the middle. 

 These bands of brown are separated by spaces of a light sage green, 

 which are about as wide as the brown bands on the posterior half of 

 the whorls between the sutures; the green area fading to yellow 

 anteriorly. These light areas are speckled with small dots of chestnut 

 and clouded in places with pale brown. The base is pale green, 

 profusely spotted with dots and blotches of red. Nuclear whorls two 

 and a quarter, depressed helicoid. Postnuclear whorls evenly 

 rounded, marked with two, broad, spiral bands, which extend over the 

 anterior half of the whorls between the sutures, where they appear 

 as two turns of a bandage. The periphery of the last whorl is marked 

 by a moderately strong spiral keel which renders it angulated. 

 Sutures feebly constricted. Base short, well rounded, broadly 

 umbilicated; marked by seven broad low bands which grow suc- 

 cessively wider from the umbilical edge toward the periphery. These 

 bands appear as a series of turns of a bandage. Umbilicus 

 without any spiral sculpture. The entire surface of spire and base 

 is marked with faint retractive lines of growth. Aperture very 

 oblique, oval ; outer and basal lips thin, showing the external markings 

 within; inner lip quite thick, evenly curved; parietal wall glazed 

 with a very thin callus. 



The type and two specimens of this species, Cat. No. 43011, 

 U.S.N.M., come from the Cape of Good Hope. The type has two 

 and one-half postnuclear whorls, and measures: Altitude, 3.5 mm.; 

 greater diameter, 5 mm. 



GIBBULA TRYONI Pilsbry. 



Cat. No. 186873, U.S.N.M., three specimens from Port Alfred 

 (Coll. No. 243). 



