Occasional Papers of the Museum of Zoology 77 



Distribution: Curasao; one specimen collected at type 

 locality. 



Shell (fig. xv-54) : small, depressed turbinate ; light horn- 

 colored ; thin and shining. AVhorls : 41/4 ; convex ; gradually 

 and regularly increasing ; suture shallow. Growth striae : well 

 marked, especially on the base, which shows quite regularly 

 spaced, impressed lines. Spiral striae : present, but much 

 weaker and more irregular than is usual in the genus. Um- 

 bilicus : small, about 1/12 of the major diameter of the shell ; 

 circular. Aperture : subvertical, reniform. Peristome : simple, 

 sharp, incomplete. 



Radula : C/3 ; L5/3 ; M19/3 + 4/4 + 1/1 ; or 25-5-1-5-23. 

 Form of teeth very similar to those of G. gundlachi (Pfr.),*^ 

 although the lateral cusps of the central are somewhat more 

 acuminate and the outer cusp of the first marginal is smaller 

 and more distant from the two larger ones. Jaw: much as 

 in G. gundlachi {I. c, fig. 3). 



Measurements 



altitude maj. diam. min. diam. alt. apert. diam. apert. whorls 



1.63 150(2.40) 130(2.13) 63(1.03) 120(1.22) 4% 



The practical absence of spiral sculpture makes this species 

 appear closest to Guppya miamiensis Pilsbry (1903; Naut., 

 XVII, 77) from Florida, but the Curasao shell is more globose, 

 with a more depressed spire and shallower suture. The regu- 

 larity of the impressed striations on the base is also a notice- 

 able difference. 



HELICIDAE 



Thysanophora crinita arubana, new subspecies 



Type locality: (A4a) at base of northern escarpment of 

 Seroe Canashito, Aruba. 



431922; Oce. Papers Mus. Zool. Univ. Mich.; no. 106, p. 45, fig. 

 xvii-1. 



