64 University of Michigan 



Distribution of species: Curasao; western side north of 

 Bullen Baai, and east in the northern hill to (at least) the 

 Tafelberg of Sint Hyronimus. A single, dead specimen (acci- 

 dental?) from Seroe Spreit. Aruba: all of the limestone por- 

 tion and narrowly invades the metamorphic rocks. Almost 

 entirely terrestrial in habits. 1,460 specimens collected. 



Distribution of subspecies: Curagao; north of Landhuis of 

 Campo Sint Kruis; mainly restricted to wooded valleys and 

 rocky hillsides in the central region of older rocks (Cbl6, 

 17abc; 20) ; also a somewhat different form from the Tafel- 

 berg of Sint Hyronimus (C20). Frequent in well-wooded 

 valleys; aestivates deep down in the talus and rock crevices; 

 comes to the surface during rains but appears never to go far 

 from the ground, even on the trunks of the larger trees. 282 

 specimens collected. 



Shell (fig. xiii-G) : elongate-conic; rather thin. Color: last 

 whorl dark plum-colored (dark, smoky amber by transmitted 

 light), shading on the penultimate whorl into the dark horn 

 color of the earlier whorls, which show indefinite, dark, spiral 

 bands ; sculpture tipped with bluish white ; eroded apex and 

 apical plug dark horn color to orange and plum color. Whorls : 

 6 (in one, entire, male shell), of which about 31/2 are retained; 

 more convexly rounded and with deeper suture than in mega- 

 clieilos; the diameter increases gradually and regularly from 

 the first to the last. Sculpture of last whorl (fig. x-37) : 

 similar to pilsbryi ; regular, compressed growth-riblets, which 

 are closely spaced but much narrower than their interspaces ; 

 spiral sculpture of numerous (15 to 21 counted), regular, 

 compressed ridges, which are more widely spaced in the umbili- 

 cal region than on the sides, and are considerably heavier than 

 the growth-riblets but are surmounted by them ; intersections 

 developed as lanceolate cusps. Earlier whorls : similar to 

 pilshryi; cusps at intersections less pronounced. Subapical 

 whorls (young shells) : sculpture similar to those of megachei- 

 los; not so slender {i.e., apical angle greater). Umbilicus: 

 smaller than in megacheilos ; partially hidden by peristome. 

 Aperture: relatively smaller than in megacheilos, but similar 



