338 CALIFORNIA ACADEMY OF SCIENCES. 



395. Fissuridea aspera Eschscholtz. 



Fissnrella aspera EsCH., Zool. Atlas, Vol. V, p. 21, PI. XXIII, fig. 5, 1833. 



Glyphis aspera EscH., Cpr., Proc. Zool. Soc, 1856, p. 223. Cpr., Brit. Assn. Rept., 1863, p. 651. 



Gabb, Pal. Cal., Vol. II, p. 85, 1869. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, 



p. 241. Keep, West Coast Shells, p. 96, fig. 80, 1892. 

 Fissuridea aspera EscH., Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 197. 



Shell oblong, conical; anterior and posterior slopes only very slightly convex; apical hole 

 anterior to center, nearly circular, the plane of its outer rim sloping considerably forward; numerous 

 prominent, straight, rough ribs radiate from the apical hole and produce a corrugated margin for the 

 shell; inner side of rim corrugated and slightly effuse; inner surface smooth. 



Dimensiotis . — Long. 60 mm.; lat. 42 mm.; alt. 23 mm. 



Easily distiaguishable by its large size and prominent, rough, radiating I'idges 

 and alternating color bauds. Has fewer and rougher ribs than F. murina, and a 

 more elliptical apical hole. 



Not uncommon in the lower San Pedro series at Deadman Island and San 

 Pedro; common in the upper San Pedro series at Crawfish George's, and rare in the 

 same formation at Los Cerritos, Deadman Island, and San Pedro. 



Living. — Sitka to San Pedro (Cooper). 



Pleistocene. — Santa Barbara to San Pedro (Cooper): San Pedro (Arnold). 



396. Fissuridea inaequalis Soiverby. 



Fissurella incequalis Shy., Proc. Zool. Soc, 1834, p. 126; Conch. 111., fig. 45. Reeve, Conch. 



Icon., fig. 50. 

 Glyphis inizqualis ^wi . , Cpr., Brit. Assn. Rept., 1856, p. 184, PI. VII, figs. 4^-4 «. Tryon, Man. 



Conch., Vol. XII, p. 215, PI. XXXIV, figs. 63, 64, 1890. 

 Fissurella pica Sby., Proc. Zool. Soc, 1834, p. 126; Conch. 111., Vol. II, figs. 32, 33. Reeve, 



Conch. Icon., fig. 49. 

 Fissurella inaqualis \a.r. pica Sby., Cpr., Brit. Assn. Rept., 1856, p. 184. Tryon, Man. Conch., 



Vol. XII, p. 215. PI. XXXIV, fig. 64, 1890. 



Shell oblong, conical, much depressed; anterior and posterior surfaces convex; lateral view 

 of margin a line convex upward (as if shell had been on a convex surface); radiating ridges numer- 

 ous and fine; concentric ridges numerous and nearly as prominent as the radiating ridges; the two 

 systems of lines giving the surface a decidedly cancellate appearance; apical hole slightly oblong, 

 anterior to center; inner surface smooth; inner surface of margin finely corrugated; color white. 



Dimensions. — Long. 22.5 mm.; lat. 12 mm.; alt. 6 mm. 



Distinguishable from other members of this genus occurring in this formation 

 by its small size and the convex appearance of the sloping sides. The specimen 

 described was identified by Dr. Dall. 



Six specimens in the upper San Pedro series of San Pedro; also found in the 

 same horizon at Los Cerritos, Deadman Island, and Long Beach. 



Living. — Guacomayo; Gala2)agos Islands (Carpenter). 



Pleistocene. — San Pedro (Arnold). 



