120 GASTROCOPTA. 



Subgenus Cavipupa, n. subg. 



The shell is broadly and deeply umbilicate, of few, strongly 

 convex whorls; apertural teeth as in Gastrocopta s. sir., the 

 basal fold subcolumellar in position. Type G. euryomphala. 



In the last whorl the diameter of the columellar axis is 

 contained about three and a half times in that of the shell. 

 It tapers rapidly upwards (PI. 22, fig. 3). By the open 

 umbilicus this group resembles the American genus Chaenaxis ; 

 both were doubtless derived from the typical group of Gastro- 

 copta, but of course independently. 



Gastrocopta euryomphala, new species. PI. 22, figs. 3, 4, 5, 6. 



The shell is thin, whitish (dead), widely and deeply 

 umbilicate, conic, composed of 4^/2 very convex whorls, the 

 penultimate whorl bulging very conspicuously, the last whorl 

 becoming flattened peripherally in its last half, and marked 

 with a short groove over the position of the lower-palatal fold ; 

 without swelling or crest behind the outer lip. Suture very 

 deep. Sculpture of microscopic granulation on the first whorl, 

 the later whorls with fine, somewhat uneven growth striae. 

 The aperture is shortly oval, with rather thin, broadly ex- 

 panded and continuous peristome, the upper margin either 

 free or shortly adnate to the preceding whorl. Parietal lamella 

 straight and rather strong; angular lamella short, uniting 

 with the parietal at the front third of the length of the latter. 

 Columellar lamella median, strong, turning down a little at 

 its inner end. Lower-palatal fold strong, elongate, the upper- 

 palatal and basal folds tuberculiform. 



Length 2.2 mm., diam. 1.3 mm. Type. 



Length 2.1 mm., diam. 1.3 mm. 



Philippine Islands : Bintuan, Busuanga. 160431 A. N. S. P. 

 (Quadras). 



The large umbilicus and conspicuously convex whorls dis- 

 tinguish this from all other known Philippine species. The 

 specimens were received through Mr. "Walter F. Webb, with- 

 out name, but I think that they are without much doubt tlie 

 species which von Moellendorff called Leucochilus eury- 



