WEST AMERICAN PYEAMIDELLID MOLLUSKS. 37 



eight and one-half post-nuclear whorls and measures: Length 4.5 

 mm., diameter 1.4 mm. vSix specimens (Cat. no. 1(33240, U.S.N.M), 

 were dredged at U. S. Bureau of Fisheries station 2901 in 48 fathoms, 

 temperature 55°. 1, oft" Santa Rosa Island. Four specimens were 

 obtained by the University of California, at station 81, off wSan Diego, 

 and another individual at station 19, off Kewport, California. 



TURBONILLA (CHEMNITZIA) PARAMCEA, new name. 



Plate 2, figs. 4, 4a. 



Chemnitziu similis C. B. Adams, Ann. Lyo. of Nat. Hist. N. Y., vol. 5, 1852, 

 pp. 392-393. 



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

 Post-nuclear whorls strongly rounded, roundly shouldered at the 

 summit, marked by moderately strong, rounded, protractive axial 

 ribs, of which 16 occur upon the first, 18 upon the second and third, 

 20 u])on the fourth to seventh, 22 upon the eighth and the penulti- 

 mate whorl. Intercostal spaces a little wider than the ribs, terminat- 

 ing a little above the sutures. Sutures constricted. Periphery and 

 the short base of the last whorl well rounded. Aperture (defective); 

 columella stout, somewhat sinuous. 



The above description is based upon Professor Adams's type, which 

 has lost the nucleus and early whorls. The ten remaining measure: 

 Length 5.9 mm., -diameter 1.5 mm. It comes from Panama. 



This species resembles Turhonilla {Strioturbonilla) pananiensis 

 C. B. Adams, ])ut differs in having the v/horls more rounded, fewer 

 and less strongly develoj^ed libs and more constricted sutures. 



TURBONILLA (CHEMNITZIA) HOUSERI, new species. 



Plate 2, figs. 15, 15a. 



Shell small, elongate-conic, milk-white. Nuclear whorls two and 

 one-fourth, forming an elevated helicoid spire, the axis of which is at 

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

 about one-fourth immersed. Post-nuclear whorls strongly rounded, 

 slightl}" shouldered at the sunnnit, marked by strong, sublamellar, 

 decidedly protractive axial ribs, which are so arranged as to pj'acti- 

 cally form continuous oblique lines, from whorl to whorl. Of these 

 ribs 14 appear upon the first to third, 16 ui)on the fourth and fifth, 

 and 18 upon the remaining whorls. Intercostal spaces about as wide 

 as the ribs, deeply impressed. Sutures somewhat constricted. 

 Periphery of the last whorl and base well rounded. Aperture rhom- 

 boidal; outer lip thin, columella moderately strong, slightly curved 

 and slightly reflected. 



The two cotypes (Cat. no. 206853, U.S.N.M.) were dredged at U. S. 

 Bureau of Fisheries station 2813, in 40 fathoms, bottom temperature 

 81°, on coral sand bottom, off Galapagos Islands. One of these is a 

 25G5— Bull. 68—09 4 



