90 BULLETIN 08, UNITED STATES NATIONAL MUSEUM. 



TURBONILLA (PYRGISCUS) MACBRIDEI, new species. 

 Plates, figs. 13, VM. 



Shell exceedingly slender, light yellow, with a broader darker yellow 

 band immediately below the summit and another halfway between 

 this and the suture. Nuclear whorls large, one and three-fourths, 

 forming a depressed helicoid spire, the axis of which is at right angles 

 to that of the succeeding turns, on the first of which it rests, but is not 

 immersed. Post-nuclear whorls exceedingly high between the sutures, 

 moderately rounded, marked by slender, very regular, slightly curved, 

 well rounded, somewhat retractive axial ribs, of which 24 occur upon 

 the first, 22 upon the second and third, 24 upon the fourth and fifth, 

 26 upon the sixth and seventh, and about 32 upon the penidtimate 

 whorl. Intercostal spaces about as wide as the ribs, well impressed, 

 marked by fifteen equal and equally spaced spiral series of pits, which 

 owing to the narrowness of the intercostal spaces, appear as mere 

 punctations. Sutures well marked. Periphery of the last whorl 

 without spiral sculpture. Base moderately long, marked by the con- 

 tinuations of the axial ribs, and six equal and equally spaced spiral 

 striations on its anterior two-thirds. Aperture oval; posterior angle 

 acute; outer lip thin, showing the external sculpture within; colu- 

 mella slender, decidedly flexuose, and very slightly revolute. 



The type (Cat. no. 191563 U.S.N.M.) of this exceedingly slender 

 shell comes from U. S. Bureau of Fisheries, station 2826, in 9^ fathoms, 

 ofl^ La Paz, Lower California. It has nine post-nuclear whorls, and 

 measures: Length 4 mm., diameter 0.8 mm. 



Named for Prof. Thomas H. Macbride. 



TURBONILLA (PYRGISCUS) NUTTALLI, new species. 



Plate 8, fig. 2. 



Shell large, elongate-conic, yellowish- white, with a light-brown 

 area about the columella. (Nuclear whorls decollated.) Post- 

 nuclear whorls well rounded, slightly shouldered at the summit, 

 scarcely at all contracted at the periphery; marked by strong, narrow, 

 well rounded, slightly protractive axial ribs, of which 14 occur upon 

 the third, 16 upon the fourth to eighth, and 18 upon the remaining 

 turns. Intercostal spaces about one and one-half times as wide as 

 the ribs, shallow, marked by about 30 incised spiral lines which are 

 strongest at the periphery and gradually weaken toward the summit. 

 A moderately broad, plain area on the middle between the sutures 

 is left unmarked. Periphery and base of the last whorl well rounded, 

 marked by the feeble continuations of the axial ribs and numerous 

 exceedingly fine, closely spaced, wavy, spiral striations. Aperture 

 small, rhomboidal; posterior angle obtuse; outer lip thin, showing 

 the external sculpture within; columella strong, straight, and revo- 

 lute. 



