204 



GASTROCOPTA. 



In some lots most of the fully adult shells have an infra- 

 parietal tubercle, as in figs. 2, 2a, the other characters remain- 

 ing typical. 



3 4a ^ 3a 



Figs. 3, 3#, 4, 4a — G. curacoana, Campo el Hato, Bonaire. 



It is an abundant species, found at many localities on the 

 islands named. 



Gastrocopta octonaria Pilsbry. Text-figs. 5 to la. 



In shape this species is somewhat broader below and has a 

 more rapidly tapering spire than typical G. curacoana; it is 

 of a slightly lighter brown color, the apical whorls pale or 

 whitish. The whorls are strongly convex. The angulo-parietal 

 lamella is strongly bifid; in a basal view, the parietal shows 

 no spur on the columellar side. A tubercular, rather deeply 

 placed infraparietal lamella is present. The columellar lamella 

 is strongly developed; below its inner end there is a strong 

 subcolumellar tubercle, somewhat united with the columellar. 

 The palatal folds are similar to those of G. curacoana in shape 

 and positions, but they are generally white ; the lower-palatal 

 is long, the inner half curved. The peristome is reflected, 

 thickened within except at the sinulus. 



Length 2.3 mm., diam. above aperture 0.95 mm. ; 5% whorls. 



