Occasional Papers of the Museum of Zoology 91 



regular growth-riblets. Plane of aperture considerably in 

 front of periphery of last whorl. 



Radula (fig. xvi-65) : C/3-4, L2/2, M7/2 + 1/0; or 8-2-1- 

 2-8. Central: with verj- slender base; the outer cusps are 

 large, but one or two, very variable, smaller cusps lie between 

 them ; this seems to indicate a tooth that is becoming bicuspid 

 by the suppression of the central cusp of the tricuspid type. 

 The accessory cusp of the inner lateral is aculeate in shape, 

 while that of the outer lateral is broader and more hoe-shaped. 

 The slender bases of the small marginals are very irregular at 

 their posterior ends, while the lateral corner of the anterior 

 margin is produced into a sharp point. 124 rows of teeth 

 counted in a radula which lacks the unformed, posterior 

 portion. 



Jaw: consists of about 44, thin, slender, subrectangular, 

 overlapping plates, which are shorter near the center where 

 they form a triangle. 



Measurements 



Typical raveni attains the largest size and has the most 

 closely spaced riblets of any of the forms in the Dutch Lee- 

 ward Islands ; all of these are placed by their apical sculpture 

 in the mainland group of Brachypodella s. s. (c/. Pilsbry, 

 op. cit.). As will be noted from the measurements of this and 

 the following forms, the few complete shells obtained are con- 

 siderably below the maximum size. The largest shells also 

 appear to have developed the greatest number of whorls. 



Brachypodella raveni sanctaebarbarae, new subspecies 



Type locality: (C2a) at base of northern escarpment of the 

 Tafelberg of Santa Barbara, southern Curacao. 



Distribution : Curacao ; only found at the base of the north- 

 ern and western escarpments of this Tafelberg (C2). 



