AKNOLD — THE PALEONTOLOGY AND STKATIGRAI'HY OF SAN PEDKO. 287 



Young shells look iiuicli like certain species of Trito)i on account of varices. 

 Common iu the Pliocene of Doadniaii Islaiid; rarer in the lower Sau Pedro series at 

 Deadinan Island, and only occasionally found in the upper San Pedro series at 

 Deadnian Island, San Pedro, and Crawfish Georj;e's. The specimen figured is from 

 the Pliocene of Deadman Island, and is now in the collection of Delos Arnold. 



Living. — Straits of Fuca to Monterey; Japan (Cooper): dredged olT San 

 Diego (Raymond): Kodiak Island (Snodgrass). 



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

 Pliocene. — San Pedro (Arnold). 



Genus Ranella Lamarck. 



Shell ovate or oblong, compressed, with two rows of continuous varices, one on each side; 

 aperture oval; columella arcuated and ridged, or crenulated; canal short, recurved; outer lip 

 crenated. 



Ranella spinonn Lam. is a characteristic si)ecies. 



308. Ranella calif ornica Hindu. 



Ranella californica Hds., Ann. Nat. Hist., Vol. II, 1843, p. 255; Voyage Sulphur, p. 12, PI. II, 

 figs. 3 and 5, 1844. Cpr., Brit. Assn. Rept., 1863, p. 661. Tryon, Man. Conch., 

 Vol. Ill, p. 40, PI. XXI, fig. 32; PI. XXII, fig. 42, 1881. Gabb, Pal. Cal., Vol. II, p. 73, 

 1869. Keep, West Coast Shells, p. 44, fig. 24, 1S92. Willi.\.mson, Proc. U. vS. Nat. 

 Mus., Vol. XV, 1892, p. 211. 



Shell large, broadly fijsiform; spire elevated, about one-half length of aperture; whorls five, 

 convex, each with two prominent, rounded, rather reflexed varices, each set forming a continuous 

 varix from apex to base; between varices are one or two prominent rows of rounded nodes, each 

 row having from one to four, and numerous rugose revolving ridges of varying prominence; suture 

 deeply impressed, distinct; aperture subovate; outer lip thickened, ridged, denticulated; inner lip 

 incrusted, the spiral ornamentation sometimes showing through the incrustation; columella curved, 

 flattened, widened; canal short. 



Dimensions. — Long, go mm.; lat. 67 mm.; body-whorl 70 mm.; aperture, including canal, 

 53 mm.; defl. 76 degrees. 



This shell is easily distinguishable by its size and general .solid appearance. 

 Rare in the upper San Pedro series of San Pedro; three perfect specimens found; 

 one fine specimen from the upper San Pedro series of Los Cerritos; also found at 

 Deadman Island and Crawfish George's in the same horizon. Found in the Pleis- 

 tocene at Pacific Beach, San Diego. 



Living. — Santa Barbara to Lower California (Carpenter). 



Pleistocene. — Santa Barbara; San Pedro (Gabb): San Pedro; San Diego 

 (Arnold). 



Pliocene. — Kirker's Pass. 



