Occasional Papers of flie Musdim of Zoology 49 



tively much more prominent than the spiral sculpture, 

 although the latter is usually more evident than in aurantia. 



Tudora rupis rupis H. Burrington Baker 

 (1924; Naut. XXXVII, 93) 



Type locality : ( C2a ) at base of northern cliffs of Taf elberg, 

 of Santa Barbara, southern Curacao. 



Distribution of species : Curagao ; limestone of western side, 

 south of Spaansche Baai. 290 specimens collected. 



Distribution of subspecies: Curacao; only found near the 

 base of the cliffs on the northern and western sides of the 

 Taf elberg (C2). Quite common; on trees and brush, also 

 found under limestone rocks. 95 specimens collected. 



Shell (fig. xii-E) : somewhat less solid than aurantia. 

 Ground color : white to buff or pink ; spiral bands present or 

 absent, pink to very dark chocolate with purplish tinge, rarely 

 solid and then usually coalescent, normally broken and com- 

 monly with blotches connected so as to form irregular varices 

 parallel to the growth-sculpture ; eroded apex and apical plug, 

 orange to purplish black. Whorls: about 9, of which about 

 41/^ are usually retained; not markedly convex and with 

 suture even shallower than in aurantia. Last whorl (fig. 

 x-29) : growth-cords quite regular but usually obscure, low 

 and rounded; spiral sculpture of about 8, prominent, rounded 

 ridges, which (typically) are scarcely surmounted and not 

 broken by the growth sculpture. Earlier Avhorls : growth 

 sculpture relatively more prominent ; either cancellate or 

 with spiral sculpture surmounted by cusp-like thickenings 

 of the growth sculpture. Third and fourth whorls (young 

 shells) : with more widely spaced and stouter growth-riblets 

 than in aurantia; these show less tendency to form buttresses 

 at the sutures. Umbilicus: rimate. Aperture: ovoid, with 

 long axis quite oblique to that of shell; internally buff to 

 chocolate-brown, and sometimes showing the spiral bands; 

 with white, peristomal callus. Peristome : sharp, always inter- 

 rupted for a short distance on the parietal wall; well and 

 rather abruptly expanded along the palatal and basal walls, 



