68 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



MELANELLA THALIA, new species. 

 Plate 19, fig. 9. 



Shell small, elongate-conic, very slightly falcate, bluish white; 

 translucent. The whorls are very gently rounded; appressed at the 

 summit, through which the preceding whorl shines, which gives the 

 shell the appearance of having a double suture. Suture scarcely 

 marked. Periphery of the last whorl slightly inflated. Base mod- 

 erately long, well rounded; entire surface marked by exceedingly 

 fine lines of growth, and an occasional inconspicuous varix. Aperture 

 oval; posterior angle acute; outer lip clavate; inner lip very oblique, 

 slender, strongly curved and decidedly reflected, free; parietal wall 

 covered with a moderately thick callus. 



The type and two other specimens, Cat. No. 187078, U.S.N.M., 

 come from Port Alfred (Coll. No. 619). The type has eight whorls, 

 and measures: Length, 3.2 mm.; diameter, 1.1 mm. 



MELANELLA ASSER, new species. 

 Plate 25, fig. 7. 



Shell very minute, bluish white; transparent; not falcate. Whorls 

 almost flattened; appressed at the summit, through which the pre- 

 ceding whorl shines, which lends the shell the aspect of having a 

 double suture. Suture scarcely perceptible. Periphery of the last 

 whorl well rounded. Base moderately long, well rounded; entire 

 surface of spire and base marked by exceedingly fine, incremental 

 lines. No varicial markings are apparent on any of our shells. 

 Aperture oval, posterior angle acute; outer lip 'clavate; inner lip 

 short, curved, slightly reflected; parietal wall covered by a moder- 

 ately thick callus. 



The type and two specimens, Cat. No. 187079, U.S.N.M., come 

 from Port Alfred (Coll. No. 620). The type has five and one-half 

 whorls, and measures: Length, 1.7 mm.; diameter, 0.7 mm. 



Cat. No. 250382, U.S.N.M., contains another specimen from the 

 same locality .(Coll. No. 1255). 



MELANELLA, species? 



Cat. No. 250385, U.S.N.M., contains the tip of a large, straight 

 species from Port Alfred, differing from any of those I have seen 

 from South Africa (Coll. No. 1258). 



MELANELLA ACRIFA, new species. 

 Plate 20, fig. 8. 



Shell large, regularly elongate-conic, thin. Nuclear whorls two, 

 well rounded, forming a somewhat bulbous apex. Postnuclear turns 

 well rounded, appressed at the summit, the appressed portion ap- 

 pearing as a slender thread; entire surface marked by almost -vertical, 

 somewhat sinuous, strongly curved fines of growth. Sutures strongly 



