6 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.66. 



Suture slightly constricted. Periphery of the last whorl well 

 rounded. Base short, well rounded, marked on the anterior two- 

 thirds by 6 subequally spaced incised spiral lines, of which the pos- 

 terior four are a little stronger than the rest. Aperture oval; pos- 

 terior angle acute; outer lip thin, showing the external sculpture 

 within; inner lip flexuous, reflected over and appressed to the base 

 for three-fourths of its length, and provided with a rather strong 

 fold a little anterior to its insertion ; parietal wall covered by a thin 

 callus. 



The type. Cat. No. 359760, U.S.N.M., has 5.8 whorls remaining, 

 which measure : Length 4.1 mm., diameter 1 mm. 



TURBONILLA (PYRGISCUS) EVADNA, new species. 



Plate 2, fig. 7. 



Shell elongate-conic, bluish white, semidiaphanous. Nuclear 

 whorls decollated. Postnuclear w^horls high between summit and 

 suture, appressed at the summit, crossed by low, rounded, almost ver- 

 tical axial ribs, of which 18 occur upon the first and second of the 

 remaining turns, 20 upon the third, 22 upon the fourth, 24 upon the 

 fifth, 26 upon the sixth, and 27 upon the last whorl. These ribs be- 

 come enfeebled toward the sunmiit, which they render slightly sin- 

 uous. Intercostal spaces a little wider than the ribs, crossed by 11 

 incised spiral lines, which are of somewhat irregular strength and 

 spacing, the peripheral and the one posterior to the periphery being 

 much wider than the rest. Suture moderately constricted. Periph- 

 ery of the last whorl well rounded. Base short, strongly rounded, 

 marked by 8 rather strongly incised spiral lines, between which finer 

 striations occur. Aperture oval; posterior angle obtuse; outer lip 

 thin, showing the external sculpture within; inner lip sinuous, re- 

 flected over and appressed to the base for the posterior two-thirds of 

 its length, provided with a strong obtuse oblique fold a little anterior 

 to its insertion; parietal wall covered by a thick callus. 



The type. Cat. No. 359761, U.S.N.M., has 8.5 whorls remaining 

 and measures : Length 5.4 mm., diameter 1.3 mm. 



TURBONILLA (BARTSCHELLA) SEMELA, new species. 



Plate 2, fig. 1. 



Shell elongate-conic, bluish-white, semitranslucent. Nuclear 

 whorls, at least two, forming a depressed helicoid spire, which is 

 obliquely half immersed in the first of the succeeding turns. Post- 

 nuclear wliorls strongly rounded, appressed at the summit, marked 

 by very slightly protractive slender axial ribs, of which 22 occur 

 upon the first, 24 upon the second and third, and 26 upon the remain- 



