WEST AMEEICAN PYRAMIDELLID MOLLUSKS. 117 



TURBONILLA (MORMULA) SANTOSANA, new species. 

 Plate 11, fig. 7. 



Shell broadly conic, milk-white. (Nuclear whorls decollated.) 

 Post-nuclear whorls inflated, well rounded, appressed at the summit, 

 strongly contracted at the sutures, marked by strong, sublamellar, 

 curved, slightly protractive axial ribs, of which 16 occur upon the 

 second to fifth, 18 upon the sixth, and 20 upon the penultimate turn. 

 Intercostal spaces about two times as wide as the ribs, terminating at 

 the periphery, marked by a strong series of spiral pits at the periphery 

 and six strongly incised lines, which are equally spaced, excepting the 

 third and fourth below the summit, which are a little closer than the 

 rest. Sutures strongly impressed. Periphery of the last whorl well 

 rounded. Base short, well rounded, marked by three weakly in- 

 cised, equally spaced, spiral striations. Aperture ?; outer lip re- 

 enforced within by five strong spiral cords; three of which, a little 

 weaker than the rest, are between the periphery and the summit, and 

 two on the base; columella strong, twisted, and revolute, with an 

 oblique fold near its insertion. 



The type (Cat. no. 162689,U.S.N.M.) was dredged at U. S.Bureau, 

 of Fisheries station 2830, in 66 fathoms, temperature 74.1°, off 

 Todos Santos, Lower California. It has lost the nucleus and prob- 

 ably the first postnuclear turn ; the eight remaining wdiorls measure : 

 Length 3.7 mm., diameter 1.3 mm. 



TURBONILLA (MORMULA) PENTALOPHA Dall and Bartsch. 



Plate 11, figs. 3, 3a. 



Turbonilla (Lancea) pentalopha Dall and Bartsch, Mem. Cal. Acad. Sci., vol. 3, 

 1903, p. 282, pi. 1, figs. 1, la. 



Shell elongate-conic, chocolate-brown. Nuclear whorls small, 

 three, forming a depressed, helicoid spire, whose axis is at right 

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

 about one-third immersed. Post-nuclear whorls rounded on the 

 earlier and flattened on the later turns, marked by strong, rounded, 

 somewhat flexuose, slightly retractive, axial ribs, which are scarcely 

 at all expressed on the first, and of which there are 18 upon the first 

 and second, 20 upon the third and fourth, 22 upon the fifth, 24 upon 

 the sixth, and 28 upon the penultimate turn. Intercostal spaces as 

 wide as the ribs, marked by six equal and equally spaced, spiral series 

 of pits which pass up on the sides of the ribs, but do not cross them. 

 Sutures well impressed. Periphery and base of the last whorl well 

 rounded, marked by the continuations of the axial ribs and seven 

 equally spaced spiral striations, agreeing in strength with those on 

 the spire. The first spiral line above and below the periphery are 

 a little farther apart than the rest. Aperture large, oval; posterior 

 2565— Bull. 68—09 9 



