172 CALlFOENIA ACADEMY OF SCIENCES. 



Pliocene. — Santa Rosa; San Ramon, Kirker's Pass, Contra Costa County; San 

 Fernando; San Diego well (Cooper). 



Miocene. — Toraales, Marin County; Martinez, Contra Costa County (Cooper). 



121. Solen sicarius Gould. 



Solen stearins Gv.T>. , Proc. Bost. Soc. Nat. Hist., Vol. Ill, 1850, p. 214; Wilkes' Expl. Exped., 

 Vol. XII, p. 287, fig. 501, 1852. Carpenter, Brit. Assn. Rept., 1863, p. 638. 

 Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 265. Keep, West Coast Shells, 

 p. 202, fig. 173, 1892. Williamson, Proc. U. S. Nat. Mus. , Vol. XV, 1892, p. 184. 

 Dall, Trans. Wagner Inst. Sci. , Vol. Ill, Part 5, 1900, p. 952. 



Shell of medium size, elongated, transversely oblong, cylindrical, slightly falcate; beaks 

 terminal; anterior extremity truncate obliquely at angle of about 30 degrees, somewhat everted, the 

 portion posterior to a line across from the beak to the base, concave; posterior extremity rounded; 

 dorsal edge rectilinear; ventral edge regularly arcuate; surface undulated by lines of growth; hinge 

 with single, erect, recurved, triangular tooth in each valve. 



Diine7isions. — Long. 63 mm.; alt. i6mm. ; diam. 9'mm. 



Distinguishable by its terminal beak and rather falcate outline. Specimens 

 identified by Dr. Dall. 



Rather rare in the Pleistocene at Deadman Island and Timra's Point; com- 

 mon in the lower San Pedro series at Deadman Island and San Pedro; rare in 

 the upper San Pedro series at Los Cerritos, San Pedro, Crawfish George's, and 

 Deadman Island. 



Living. — Straits of Fuca to San Pedro; Japan (Cooper). 



Pleistocene. — San Pedro (Arnold). 



Pliocene. — Twelve Mile Creek, San Mateo County; San Fernando (Cooper). 



Miocene. — Walnut Creek, Contra Costa County (Cooper). 



Genus Siliqua Megerle. 



Shell smooth, oblong; epidermis polished; an umbonal rib extending across tiie interior of 

 the valve; pallial sinus short. 



Type, Solen radius Linne. 



122. Siliqua lucida Conrad. 



bolecurtus lucida Con., Jour. Phil. Acad. Sci., Vol. VII, 1837, p. 232, PI. XVII, fig. 9; ^6". radiata 

 Linn, {^fide Conrad, Jour. Phil. Acad. Sci., 1849, p. 214). Dall, Solenidae, Proc- 

 U. S. Nat. Mus., Vol. XXII, igoo, p. 109. 



Siliqua lucida Con., Dall, Trans. Wagner Inst. Sci., Vol. Ill, Part 5, 1900, p. 957. 



Shell of medium size, oblong-oval, compressed, thin, fragile; umbo a little less than one- 

 fourth length from posterior end; interior raised callus sharp, narrow, perpendicular to dorsal margin; 

 other characteristics the same as in var. nuitalli. 



Dimensions.— hong. 32 mm.; alt. 12 mm.; diam. 5 mm.; umbo to anterior end 25 mm.; to 

 posterior end 7 mm. 



