ART. 20 ADDITIONAL MOLLUSKS FROM ECUADOR BARTSCH 9 



The typo (Cat. No. 363077, XLS.N.M.) has lost the nucleus and 

 probabl_y the first postnuclear AvJiorl. The eight and one-half re- 

 maining turns measure, length, 5.3 mm. ; diameter, l.-t mm. 



Cat. No. 363078, IJ.S.N.M., is another specimen from the same 

 locality. 



TURBONILLA (PYRGISCUS) AYA, new species 



Plate 1, fig. 10 



Shell small, elongate-conic, pale yellow. Nuclear whorls 2i/4 form- 

 ing a helicoid spire whose axis is not quite at right angles to that 

 of the succeeding turns, in the first of which it is about one-fifth 

 immersed. Postnuclear whorls slightly rounded, appressed at the 

 summit, marked by moderately strong, rounded, slightly pro- 

 tractiveiy slanting axial ribs, of which 22 occur upon the first and 

 second, 20 upon the third, 18 upon the fourtli and fifth, and 20 

 upon the last turn. The spaces separating these ribs are about as 

 wide as the ribs and crossed by seven equal and almost equally spaced 

 spiral cords. The spaces between the summit and the first, and the 

 first and second, and the third and fourtli are a litle wider than the 

 vest, which are ecjual. Suture moderately well impressed. Periphery 

 of the last whorl well rounded. Base moderately long, well rounded, 

 marked b}' seven equal and equally spaced incised spiral lines Avhich 

 are less than half the strength of those on tiie spire. There is a 

 rather broad, smooth band between the first of these and the 

 peripheral series of pits. Aperture small, oval; posterior angle 

 acute; outer lip thin showing the external sculpture within; inner 

 lip somewhat sinuous, reflected over and appressed to the base for 

 almost half its length ; parietal wall covered by a thin callus. 



The type (Cat. No. 363079, U.S.N.M.) has lost the nucleus and 

 probably the first postnuclear turn. The seven whorls remaining 

 measure, length, 4 mm.; diameter, 1.1 mm. Cat. No. 363080, 

 U.S.N.M. contains two specimens, one of vv'hicli has served for a 

 description of the nucleus. 



TURBONILLA (PYRGISCUS) MARA, ne^ species 



Plate 1, figs. 3, 6 



Shell small, elongate-conic. Nuclear whorls flesh-colored, the last 

 three pale brown, the rest pale brown near the summit, flesh-colored 

 on the rest of the spire, with the base pale brown. Nuclear whorls 

 2%, well rounded, forming a depressed helicoid spire, the axis of 

 which is at right angles to that of the succeeding turns, in the first 

 of which it is about one-fifth immersed. First postnuclear whorls 



3098—26 2 



