4 PEOCEEDINGS OF THE NATIONAL MUSEUM. vol.66. 



TURBONILLA (STRIOTURBONILLA) EVAGONE, new species. 



Plate 1, fig. 4. 



Shell elongate-conic, bluish white. Nuclear whorls decollated. 

 Postnuclear whorls flattened on the sides, almost excurved at the 

 summit, which is narrowly tabulatedly shouldered, crossed by numer- 

 ous axial ribs, which have a decidedly protractive slant, and which 

 feebly crenulate the summit. Of these ribs, 18 occur upon the first 

 and second, 20 upon the third to fifth, 22 upon the sixth and seventh, 

 26 upon the eighth, 28 upon the ninth, and 30 upon the last turn. 

 These ribs are about as wide as the spaces that separate them. The 

 latter are deeply impressed and terminate a little anterior to the 

 periphery, leaving a narrow, smooth band at the suture. Periphery 

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

 smooth, excepting lines of growth. The entire surface of the spire 

 and base is marked by microscopic spiral striations. Aperture oval ; 

 posterior angle acute; outer lip moderately thick, showing the ex- 

 ternal sculpture within; inner lip somewhat sinuous, reflected and 

 appressed for its posterior third to its preceding turn, and provided 

 with an oblique obsolete fold a little anterior to the insertion of the 

 columella ; parietal wall covered by a thin callus. 



The type. Cat. No. 359751, U.S.N.M., has 10.6 postnuclear whorls 

 and measures, length, 6.2 mm. ; diameter, 1.7 mm. Cat. No. 359752, 

 U.S.N.M., contains 7 additional specimens from the type locality. 



This is nearest related to Turho'iiilla {StHoturhonilla) panajnensis 

 C. B. Adams, but differs from it by its larger size, more robust form 

 and more numerous ribs. 



TURBONILLA (STRIOTURBONILLA) NYCHIA, new species. 



Plate 2, fig. 6. 



Shell broadly elongate-conic, bluish white. Nuclear whorls two 

 and a third, forming a depressed helicoid spire, the axis of which is 

 at right angles to the nuclear turns, in the first of which the nuclear 

 spire is about one-third immersed. Early postnuclear whorls strongly 

 rounded, the later ones less so, appressed at the summit, crossed by 

 curved, protractively slanting axial ribs, of which 20 occur upon 

 the first and second and 22 upon the remaining turns. These ribs 

 become somewhat enfeebled toward the summit, which they render 

 slightly sinuous. Intercostal spaces a little wider than the ribs, 

 crossed by 23 incised spiral lines, of which the 11 occurring on the 

 posterior two-fifths are a little finer and closer spaced than the rest, 

 the twelfth being a little stronger. The 10 succeeding are again 

 subequal, while the twenty-third forms a deep peripheral pit. The 

 latter is separated from the rest by a little wider space. The space 



