ARNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN PEDRO. 289 



Only a few specimens fonnd in the upper San Pedro series of San Pedro. 

 Living. — Santa Bai-bara to Lower California (Carjjenter). 

 Pleistocene. — San Pedro (Arnold). 



311. Trivia solandri Gray. 



Trivia so/andri Gk\^, Cpr., Brit. Assn. Rept., 1863, p. 657. Keep, West Coast Shells, p. 60, 1892. 

 Williamson, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207. 



Shell, small, ventricose, convolute; spire concealed; about thirteen elevated lines cross the 

 back of the shell; these lines are interrupted in the middle of the shell by an impressed median 

 sulcus, along the sides of which the transverse lines end in rounded nodes; the sulcus does not 

 e.xtend to either end of the shell; aperture long and narrow, with a canal at each end; inner lip 

 crenulated; outer lip inflected and crenulated. 



Ditnensions. — Long. 12.5 mm.; lat. 9.5 mm.; heigiit, when lying on aperture, 7 mm. 



This species is distinguishable from T. californica by its much larger size, 

 coarser sculpture and impressed median sulcus. 



One specimen from the lower San Pedro series of Deadman Island. 



Living. — Santa Barbara to Panama (Carpenter). 



Pleistocene. — San Pedro (Arnold). 



Genus Erato Risso. 



Shell obovate, polished; spire short, conical, distinct; aperture linear; outer lip without 

 varix, but thickened toward the middle, and denticulated within; columella with distinct plates at 

 the forepart. 



Erato Icevis Donov. is a characteristic species. 



312. Erato columbella Menke. 



Erato coluinbeHa M.KE. , Zeit. Mai., p. 183, No. 26, 1847. Cpr., Brit. Assn. Rept., 1863, p. 657. 

 Tryon, Man. Conch., Vol. V, p. 10, PI. IV, fig. 8, 1883. Keep, West Coast Shells, 

 p. 61, fig. 46, 1892. Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 240. William- 

 son, Proc. U. S. Nat. Mus., Vol. XV, 1892, p. 207. 



Shell small, pyriform; spire only slightly elevated; whorls four, nearly flat, except body- 

 whorl, which is ventricose and pyriform, and comprises most of the shell; surface smooth; suturp 

 distinct; aperture long, narrow, curved around body-whorl; outer lip finely dentate within. 



Dimensions. — Long. 7 mm.; lat. 4 mm.; body-whorl 6.5 mm.; aperture 6 mm. 



One specimen from upper San Pedro series of San Pedro. 

 Living. — Monterey to San Diego; Mazatlan (Cooper). 

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



( 37 ) April 26, 1903. 



