ARNOLD— THE PALEONTOLOGY AND STRATIGUAPHY OF SAN PEDRO, 2G1 



270. Purpura crispata Chemnitz. 



Purpura crispata Ciif.m., Conch. Cab., XI, PI. 187, figs. 1802 and 1803, 1795; KusTER, Conch. Cab., 

 p. 105, PI. XIX, figs. 3 and 4, 1837. Cpr., Brit. Assn. Rept., 1863, p. 662. Tryon, 

 Man. Conch., Vol, II,' p. 175, PI. LXIII, figs. 163-166, 168, 1880. Cooper, 7th Ann. 

 Rept. Cal. St. Min., 1888, p. 261. Keep, West Coast Shells, p. 33, fig. 13, 1892. 



Shell fusiform, thick; spire elevated; apex subacute; whorls five to seven, conve.x or 

 angulated, with one or more prominent spiral ridges on angular part of whorl; suture impressed, 

 distinct: aperture ovate to elliptical; outer lip eftuse, generally denticulate; inner lip incrusted, 

 smooth; canal short, curved backwards; umbilicus subperforate. 



Dimensions. — Long. 34 mm.; lat. 20 mm.; body-whorl 26 mm.; aperture, including canal, 

 22.5 mm.; canal 6 mm.; defl. 55 degrees. 



Tlie specimen whose dimensions are given was a stnall one, but the relative 

 proportions in this specimen seemed to be about tlie average. A very variable species, 

 some being nearly smooth and some almost spinous in their roughness. The smooth 

 forms generally lack the denticulation of the outer lip. The shell texture is very 

 well preserved in mo.st of the Pleistocene specimens, some of them being almost 

 indistinguishable from living shells. 



Not common in the upper San Pedro series of San Pedro, Deadman Island, 

 and Crawfish George's. Found in the Pliocene at Pacific Beach and lluss School, 

 San Diego. 



Living. — Sitka to Santa Barbara (Cooper). 



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



Pliocene. — Seven Mile Beach, San Mateo County (Cooper) : San Diego (Arnold). 



271. Purpura saxicola Valenciennes. 



Purpura saxicola Val., Venus, PI. VIII, fig. 4, 1846. Cpr., Brit. Assn. Rept., 1S63, p. 662, 

 =/'. lapillus Cooper (not Linn, sp., Lam.), Gabb, Pal. Cal., Vol. II, p. 75, 1869. 

 Tryon, Man. Conch., Vol. II, p. 174, PI. LIII, figs. 152, 154a, 1880. Cooper, 7th 

 Ann. Rept. Cal. St. Min., 1S88, p. 262. Keep, West Coast Shells, p. 31, fig. 11, 1892. 



Shell small, semiglobular; spire slightly elevated; apex subacute; whorls four, angulated, 

 tabular on top; body-whorl ventricose; surface ornamented with obsolete spiral ridges and fine 

 incremental lines; suture impressed, distinct; aperture large, elliptical; outer lip smooth, thin, effuse; 

 inner lip and columella flattened, incrusted, sharp; canal short. 



Dimensions. — Long. 18 mm.; lat. 13 mm.; aperture, including canal, 16 mm.; canal 

 13.5 mm.; defl. 85 degrees. 



Quite a variable form. All the Pleistocene specimens at hand show the 

 mottled or banded reddish brown coloration. Distinguishable from P. crisj)a(a by 

 the small spire, large body-whorl, large aperture, and smoothness of the shell. 



Rare in upper San Pedro series of San Pedro; three specimens. Found in 

 the Pleistocene at irrigating ditch, Ventura. 



Living. — Alaska to San Diego; Lower California (Cooper). 



