172 rXT.TFOKNIA ACADEMY OF SCIENCES. 



Pliocene. — Santa llos:i; San Ramon, Kirker'-s Pass, Contra Costa County; San 

 Fernando; San Diego well (Cooj>er). 



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



121. Solen sicarius GuuUl. 



So/m sican'HS Gi.D. , Ptoc. Bost. Soc. Nat. Hist., \o\. Ill, 1850, p. 214; Wilkes' Expl. E.xped., 



Vol. XII, p. 2S7, fig. 501, 1852. Carpenter, Brit. Assn. Rept., 1863, p. 638. 



.Cooper, 7th Ann. Rept. Cal. St. Min., 18SS, 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 e.xtremity truncate obliquely at angle of about 30 degrees, somewliat 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. 



Dimertst'oNS. — Long. 63 mm.; alt. 16 mm.; diam. 9 mm. 



Distinguishable by its terniinal beak ami 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 the intericir of 

 the valve; pallial sinus short. 



Type, Solen radius Linne. 



122. Siliqua lucida Conrad. 



iiolecurtus lucida Con., ]om. Phil. Acad. Sci., Vol. VII, 1837, p. 232, PI. XVII, fig. 9; = S. radiata 

 Lwn. (Jide Conrad, Jour. Phil. Acad. Sci., 1849, p. 214). Dall, Solenidae, Proc 

 U. S. Nat. Mus., Vol. XXII, 1900, 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. nuttalli. 



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

 posterior end 7 mm. 



