272 CALIFORNIA ACADEMY OF SCIENCES. 



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

 oblique, somewhat flexuose axial ribs, which traverse five-sixths of the exposed portion of the whorls, 

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

 intercostal spaces appear as grooves gouged out of the shell, their bases marking the fusing 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 periphery; aperture subovate; the rather thick outer lip joins the straight, somewhat 

 revolute columella at almost a right angle. 



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



The specimen figured is from the post-Pliocene of San Diego. 



This species occurs living along the California coast at 2^'"esent, but appears 

 far more abundant in the fossil state. More than five hundred individuals referable 

 to this 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. 



Plate I, Fio.s. 10 and lOn. 



Chemnitzia (f torquata var. j stylma Cpr., Ann. Mag. Nat. Hist., 3rd Sen, Vol. XV, 1865, p. 396. 



Shell like T. torquata, but more slender, with but 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. 



Dime?isions. — 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 fossil in the 

 vicinity of San Pedro and San Diego. 



Section Lancea Peas(\ 



Lancea Pease, Am. Journ. Conch., Vol. IH, 1867, p. 293. Type, Turbonilla {Laiicea) elo7igata 

 Pease, ^=Pyrgostyhcs Monterosato, Conch. Medit., p. 90, 1884. 



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

 irregular intervals on the spire, which are usually accompanied by internal lirations of the outer lip. 



289. Turbonilla (Lancea) aurantia (kirpcnier. 



Chemnitzia tridentata (? v&r.) aurantia Cpii., Brit Assn. Rept., 1863, p. 659; Jour, de Conch., Vol. XII, 

 1865, p. 147. 



Shell small, slender, solid, rather thick, reddish-brown; first tliree 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 Irom 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 



