AUNOLD — THIi PALEONTOLOGY AND SI'KATKiKAPHY OF SAN PEDltO. 281 



(jeiui.s Odostomia Fleinimj. 



Odoslomia Fleming, Edinburgh Encyclopedia, Vol. V'll, I'l. I, \>. 76, 1.S17 ? {tfx />a//c). 

 Typf , Odostomia plica/a MoNT. 



Shell with sinistral nucleus, subglobose to broadly conic; spire rarely elevated as in Tur- 

 bonilla; scul|)ture varving in the different sections from plain (Odostomia, s. s.) to highly ornamented 

 {C/trysattida); ccjlumella provided with a single fokl, which is rarely obsolete. 



Aniiuul as in TnrbonlUa. The species of tliis genu.s are (li.stiibiitu<l in all seas. 

 Tlu! original description of this genus incUuled cliicHy small land shells, with dentate 

 a|)LTtures, but also a few marine species. The land shells had alrcad}' received 

 names, so the marine species were left to carry Fleming's name, a fact recognized 

 liy him in later publications. The rarity of the original edition of the Edinburgh 

 Encyclopedia has made it very difiicidt to ascertain the facts in regard to this genus, 

 and the true date of its publication, iiut we believe the facts to l)e now established as 

 above stated. The species cited in the original publication are 0. iniersiincta, 

 0. uiiidentata, 0. plicata, 0. snndolcunsis and 0. inscnlpta. 



Section Odonlomia Fleming, s. s. 



Odostomia Fleming, Edinburgh Encyclopa'dia, Vol. VII, Ft. I, p. 76, iV,\-] {ex parte). 

 Type, Odostomia plicata Mont. 



Odostomias of more or less conical outline, devoid of all sculpture, except incremental lines, 

 and having a more or less prominent columellar fold. 



302. Odostomia tenuis Carpenter. 



Pi.ATK I, Fig. 14. 

 Odostomia tenuis Cpk., Cat. Maz. Shells, p. 412, 1856. 



Shell slender, conic, umbilicated, dingy white; nuclear whorls small, immersed; post-nuclear 

 whorls very slightly conve.x, almost flattened, scarcely contracted at base, and hardly shouldered; 

 suture not very prominent, hardly channeled; base and periphery of the last whorl well rounded; 

 apt-rture quite large, ovoid, posterior angle acute, outer lip somewhat contracted at its middle; colu- 

 mella very fle.xuous, slender and revolute; parietal wall covered by a faint callus; columellar fold 

 strong opposite the umbilical chink. 



Dimensions. — Long. 5.7 mm.; diam. 2.6 mm. 



The specimen figured is from Santa Rosa Island, California, and has seven 

 post-nnclear whorls. 



Th(i species appears to range in the recent state from Washington to Cali- 

 fornia, and has been found in the po.st-Pliocene deposits of San Diego, San Pedro, 

 and Ventura. 



Section Evalta A. Adams. 



Evatea A. Adams, Ann. .Mag. Nat. Hist., 3d Ser. , Vol. VI, i860, p. 22. Type, Odostomia ( Evalea) 



elegans A. Adams. 

 Ondina De Folin, Fonds de la Mer, p. 214, 1S70. Type, Ondina sulcata De Folin, 1. c. 



Odostomias without a.xial sculpture, having spiral striation or liration. 



( 36 ) Much 31, 1903. 



