GASTROCOPTA. 



205 



Dutch West Indies : Aruba, Curaqoa, and Bonaire. Type, 

 No. 133559 ANSP. (figs. 5, 5a), from Fort Nassau, Willem- 

 stad, Curasao (Horace Burrington Baker). 



Gastrocopta octonaria Pilsbry, Proc. A. N. S. Phila., lxxvi, 

 1924, p. 64, text-figures 5-la. 



While many specimens are separable from G. curacoana by 

 the different shape, others are indistinguishable from the 

 broader examples of that species. In a great number exam- 

 ined, the strong tubercular subcolumellar lamella is a constant 



Figs. S> 5a, 7, 7a. — G. octonaria, Fort Nassau, Willemstad. Fig. 6, specimen 

 from Seroe Djerimi, broken to show the full length of the palatal folds. 



differential character, being replaced in curacoana by a taper- 

 ing buttress. 



The whorls of G. octonaria are more convex than in G. 

 pohjptyx Pils., of St. Thomas, and it differs further by the 

 longer, curved lower-palatal fold, and by the larger subcolu- 

 mellar lamella, which isi more united with the columellar. 



In a few lots there are beautiful albino shells. 



This species was almost always found associated with G. 

 curacoana, and in a few cases with G. oarbadensis hojeda also. 



G. octonaria and G. b. hojeda require comparison with G. 

 uvidifera Guppy, of Trinidad, which has not been defined ex- 

 actly enough for comparison with related species. 



