'2l2 CALIlOltNIA ACADKMV OF SCIENCES. 



whorls; post-miclcar whorls somewhat flattened, ornamented by sixteen to twenty-two broad, 

 oblique, somewhat flexiiose axial ribs, which traverse five-sixths of the ex|)oscd portion of the whorls, 

 then fuse, leavinjj a band above the suture and the base of the last whorl devoid of sculpture; the 

 intercostal spaces appear as jrrooves (iouj^ed out of the shell, their bases markinji;^ the fusinjr point of* 

 the ribs; they are equal to the ribs in breadth; the sutures are well defined, owing to the very slight 

 shouldering of the summit and the slight contraction of the base of the whorls; last whorl slightly 

 angular at the |)eriphery; aperture subovate; the rather thick outer lip joins the straight, somewhat 

 revolute columella at almost a right angle. 



Dimensions. — Long. 10.6 mm.; diani. 2.5 mm. 



The specimen figured is tVom tlie |>ost-Plio(;cii(! of Sun Diego. 



This species occurs living along the Californiii coii.st at present, but appears 

 far more almndant in the fcssil state. More tlian five hundred individuals referable 

 to thi.s form have been examined, only six of which were recent, the remainder 

 being post-Pliocene fossils from the vicinity of San Pedro and San Diego. 



288. Turbonilla (Strioturbonilla) torquata, var. stylina Carpenter. 



Pl.ATK I, Flll.S. 10 AND lOrt. 



Chemnitzia (? torquata varj stylina Cpr., Ann. Mag. Nat. Hist., 3rd Ser., Vol. XV, 1865, jj. 396. 



Shell like T. torquata, but more slender, witii hut two nuclear whorls; having more axial 

 ribs, twenty-two to twenty-eight on the post-nuclear whorls, and the intercostal spaces extending 

 further down upon the whorls, thus diminishing the breadth of the plain band above the sutures; 

 entire surface marked by faint, wavy, spiral striations. 



Dimensions. — Long. 8 mm.; diam. i.g mm. 



The specimen figured is from Monterey. This variety has been found as far 

 north as Port Etclees, Alaska. It occurs abundantly as a post-Pliocene fo.ssil in tiie 

 vicinity of San Pedro and San J)iego. 



Section Lancea Pease. 



Lancea Pease, Am. Journ. Conch., Vol. IH, 1867, p. 293. Tyjje, Turbonilla {Latuea) clongala 

 Pease, ^Pjrgoslylus Monterosato, Conch. Medit., p. 90, 1884. 



Turbonillas with strong axial ribs and spiral sculpture, jirovided with thickened varices at 

 irregular intervals on the spire, which are usually accompanied by iiiieniil iir.itions of the outer lip. 



289. Turbonilla (Lancea) aurantia ('arpenler. 



Chemnitzia tridentata (? var.) aurantia Cpr., Brit Assn. Rept., 1863, p. 659; Jour, de Conch., Vol. XII, 

 1865, p. 147. 



Shell small, slender, solid, rather thick, reddish-brown; first three post-nuclear whorls convex, 

 five remaining post nuclear whorls (nearly) flat; whorls ornamented by twenty to twenty-six broad, 

 evenly rounded, only very slightly oblique axial ribs, which extend nearly from suture to suture; 

 the intercostal spaces appear as narrow grooves, their width is much less than the width of the ribs; 

 the spiral striations on the base and between the ribs are very faint; the sutures are well defined and 

 deep, owing to a distinct shouldering of the whorls above, and an equal contraction of the whorl at 



