510 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxm. 



40 upon the seventh whorl. On the penultimate and antepenultimate 

 whorls they are more or less irregular in form, number, and spacing. 

 Intercostal spaces much narrower than the ribs. The spiral sculpture 

 consists of 8 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 ornamented by the prolonga- 

 tion of the axial ribs and quite a number of continuous well-impressed 

 spiral lines with faint spiral striation between them. Aperture sub- 

 oval, somewhat effuse anteriorly, posterior angle obtuse (outer lip 

 fractured, very thick); columella strong, slightly curved and strongly 

 revolute with a weak, very oblique internal fold near its insertion; 

 parietal wall and um))ilical region covered by a weak callus. Colu- 

 mella and extreme anterior portion of the aperture white. 



The type (Cat. No. 74000, U.S.N.M.) belongs to 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: Length 13.5 mm., diameter 3.7 mm. 



This species is remarkable for being the largest known member of 

 the section Pyi'glscus on the west coast of America. 



Subgenus MOS.MULA A. Adams. 



Mormula A. Adams, Journ. Linn. Soc. London, VII, 1864, p. l;=Pyrgostylus Mon- 

 TERosATo, II. Nat. Hist. Sicil., 1884, p. 90. 



'Turbonillas having vertical ribs and deeply incised spiral lines; 

 also irregularly disposed varices on the outer surface, which usually 

 mark internal lirations on the outer lip. Sculpture never nodulose. 

 Type. — Mormtda 7'issoina A. Adams. 



KEY TO SPECIES OF MORMULA. 



Adult shell more than 20 mm lordi. 



Adult shell less than 15 mm. 



Deeply incised lines on the whorl between the sutures: 5 trklentata. 



Deeply incised lines on the whorl between the sutures: 12 eschscholtzi. 



TURBONILLA (MORMULA) LORDI E.A.Smith. 



Plate XLV, figs. 7, la. 



Chemnitziu lordi E. A. Smith, Ann. Mag. Nat. Hist., VI, 1880, p. 288. 



Shell very large, light brown to pale yellowish-white, variously 

 banded. Nuclear whorls two, smooth, helicoid, moderately elevated, 

 having their axis at right angles to the axis of the succeeding turns 

 and about one-fourth immersed in the first of them. Postnuclear 

 whorls well rounded, ornamented by heavy, broad, low axial ribs, of 

 which about 14 occur upon the second, 16 upon the eighth, 22 upon 



