102 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



TURBONILLA (PYRGISCUS) CASTANELLA Dall. 

 Plate 9, fig. 7. 



Turbonilla (Pyrgiscus) caslaneUa Dall, Nautilus, vol. 22, 1908, p. lSl. = Ti(rbo- 

 nilla (Pyrgiscus) msto/ira Dall and Bartsch, Proc. U. S. Nat. Mas., vol. 33, 

 1907, pp. 509, 510, pi. 47, fig. 7; not Chemnitzia castanen Keep, West Coast 

 shells, 1888, p. 5, fig. 33. 



Shell very large, stout and heavy, chestnut brown. Nuclear whorls 

 decollated. Post-nuclear whorls well rounded, ornamented by many 

 broad, flattened, more or less regular and evenly placed retractive 

 axial ribs, of which about 22 appear upon the third, 26 upon the 

 fifth, and 40 upon the seventh whorl. On the penultimate and ante- 

 penultimate whorls they are more or less irregular in form, number, 

 and spacing. Intercostal spaces much narrower than the ribs. The 

 spiral sculpture consists of eight deep, quite regularly spaced lines 

 of pits, which are very pronounced in the intercostal spaces and on 

 the sides of the ribs, but do not appear to cross their summits except 

 on the penultimate and the last whorl. Sutures well defined, simple. 

 Periphery and base of the last whorl evenly rounded, the latter orna- 

 mented by the prolongation of the axial ribs and quite a number of 

 continuous well-impressed spiral lines with faint spiral striation 

 between them. Aperture suboval, somewhat effuse anteriorly, pos- 

 terior angle obtuse (outer lip fractured, A'ery thick) ; columella strong, 

 slightly curved, and strongly revolute, with a weak, very oblique 

 internal fold near its insertion; parietal wall and umbilical region 

 covered by a weak callus. Columella and extreme anterior portion 

 of the aperture white. 



The type (Cat. no. 74000, U.S.N.M.) belongs jto the Stearns collec- 

 tion and was obtained at Monterey, California. It has 10 post- 

 nuclear whorls (the nucleus and perhaps the first three being lost), 

 and measures: I^ength 13.5 mm., diameter 3.7 mm. 



This species is remarkable for being the largest known member of 

 the section Pyrgiscus on the west coast of America. 



TURBONILLA (PYRGISCUS) INDENTATA Carpenter. 



Plate 10, fig. 10. 



Chrysallida indentatn Carpenter, Cat. Mazatlan Shells, 1856, p. 425^26. 



Shell elongate-conic, wax yellow. Nuclear whorls two, forming a 

 subglobose, helicoid spire, whose axis is almost at right angles to that 

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

 immersed. Post-nuclear whorls moderately rounded, slightly con- 

 tracted at the sutures, subtabulatedly shouldered at the summit, 

 marked by strong, slightly pro tractive, axial ribs, of which 14 occur 

 upon the first, 16 upon the second, 18 upon the third and fourth, 20 

 upon the fifth and sixth, and 22 upon the penultimate turn. Inter- 



