84 GASTROCOPTA, NORTH AMERICA, WEST INDIES. 



In his description in the P. Z. S., Pfeiffer gave the length 

 as 2% mm., evidently an error. Kuester, who described and 

 figured a specimen from Pfeiffer 's collection, noted and fig- 

 ured the palatal plicae, which Pfeiffer omitted to mention; 

 also the nodules above and below the columellar lamella. This 

 specimen may be considered the type. 



The shell averages a little larger than G. pellucida, and 

 when fresh is of a light brown color. The angulo-parietal 

 lamella is more sinuous than in either pellucida or serviLis. 

 In front view it appears strongly bifid. In a specimen in 

 which the base has been broken away (pi. 18, fig. 3) the pari- 

 etal lamella is seen to be thick, terminating forward in a low 

 projection towards the columella. The angular lamella is 

 thinner, and where it joins the parietal is strongly bent 

 towards the periphery, forming a small lobe. The columellar 

 lamella is stout and horizontal, with a callous below its inner 

 end. This callous may be quite low, not visible in a front 

 view, or it may be strongly developed, appearing as a sub- 

 columellar nodule. Among specimens evidently mature one 

 finds such variation in the same lot, but in some lots the 

 nodule does not seem to be developed. A similar callous, 

 rarely nodular (as in pi. 18, fig. 1, and in Kuester 's figure), 

 is on the axis above the columellar lamella, but this supra- 

 columellar nodule is often very weakly developed. The form 

 with well-developed supra- and infra-columellar nodules may 

 be considered typical barbadensis, since this is what Kuester 

 figured from Pfeiffer 's collection. The lower palatal plica is 

 larger than the others, and enters more deeply. The basal 

 fold is often quite small. The peristome is pale brown, and 

 from very slightly thickened to distinctly so, yet not so thick 

 as in G. rupicola. There is sometimes a very low indication 

 of a crest behind the lip, but more often none. The shape 

 varies somewhat from oblong to oblong-conic, the summit 

 always very obtuse. In color it is wood-brown, fading to cor- 

 neous at the apex. Dead shells bleach under the tropical sun 

 to grayish-buff or almost "corneous," preserving a fresh ap- 

 pearance. Measurements of Barbados shells follow : 



Length 2.05, diam. above aperture 0.85 mm. 



