338 PROCEEDINGS OF THE NATIONAL MUSEUM. 



slightly angulated, base moderately long and well rounded. Aperture 

 moderate! V large, subquadrate, posterior angle acute, outer lip thin, 

 showing tlie external sculpture within by transmitted light: columella 

 slender, oblique, somewhat revolute; columellar fold not apparent in 

 the aperture, parietal wall covered by a thin film of callus. 



There are two specimens in the Berlin collection, both belong to the 

 Duidver collection and come from Japan; one of these has been donated 

 to the U. S. National Museum and is entered as No. 185887, the other, 

 the type, has thirteen post-nuclear whorls, and measures: long. 8.2 mm. ; 

 diam. 2.1 mm. 



TUBONILLA (CHEMNITZIA) INFANTULA, new species. 

 Plate XX, tig. 2. 



Shell very small, slender, milk-white. Nucleus prominent, helicoid, 

 with elevated spire, consisting of two and one-half whorls, which are 

 about one-fourth immersed in the tirst of the later whorls and have 

 their axis at a right angle to the axis of these. Post-nuclear whorls 

 six, moderately rounded and ornamented by strong, oblique ribs, of 

 which sixteen occur upon the tirst and eighteen upon the pemdtimate 

 whorl. Intercostal spaces about as wide as the ribs, terminating 

 abi'u[)tly at the periphery. Rase smooth. Aperture moderately large; 

 onter lip (fractured). This is a young specimen; we add it to make 

 the leport complete. It was collected by Hilgendorf in Japan and 

 measures: long. 2.1 mm.; diam. .6 nmi. 



TURBONILLA (CHEMNITZIA) ACTOPORA, new species. 



Plate XX, tig. 6. 



Shell very slender, elongate-conic, white. Nuclear whorls small, 

 helicoid, oljliijutdy one-third inunersed in the first of the later whorls. 

 Post-nuclear whorls rather high between the sutures, flattened and 

 somewhat shouldered at the summit, marked by rather poorh^ devel- 

 oped, low. broad, rounded, obliquely slanting axial ri))s of which 

 fourteen appear upon the second, sixteen upon the fifth and tenth 

 whorl. On the penultimate these ribs are subobsolete. Intercostal 

 spaces shallow, narrow, terminating at the peripher}-. Periphery and 

 base of the last whorl well rounded, smooth. Aperture moderately 

 large, snbquadrate, posterior angle obtuse, outer lip thin, showing the 

 external sculpture within liy transmitted light; columella ol)li([ue, 

 sti-aight, somewhat revolute, bearing a low, rounded fold a little ante- 

 rior to its insertion; parietal wall covered by a mere film of callus. 



Vho Dunker colhH'tion contained five specimens of this species, one 

 of which has l)eeii donated to the V. S. National Museum, No. 185888, 

 all from .Japan. The type has twelve post-nuclear whorls and meas- 

 ures: loii^-. (J.SniMi.: diam. 1.5 nun. 



