AKNOLD — THE PALEONTOLOGY AND STRATIGRAPHY OF SAN ITIDRO. 289 



Only a few specimens found in tlie upper San Pedro series of San Pedro. 

 Zu'i»i^.— Santa Barbara to Lower Calit'ornia (Carpienter). 

 Pleistocene. — San Pedro (Arnold). 



311. Trivia solandri Gnti/. 



Trivia so/andri Gray, Cpk., Brit. Assn. Rept., 1863, p. 657. Keep, West Coast Shells, p. 60, 1892. 

 Williamson, Pioc. 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, aloni,-^ the sides of which the transverse lines end in rounded nodes; the sulcus does not 

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

 crenulated; outer lip inflected and crenulated. 



Dimensions. — Long. 12.5 mm.; lat. 9.5 mm.; height, when lying on aperture, 7 mm. 



This species is distinguishable from '/'. callfornica 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 Rinno. 



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

 vari.x, 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 Menlce. 



Erato colunibellaViViV.., 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. Willlwi- 

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



Shell small, pyriform; spire only slightly elevated; whorls four, nearly flat, e.xcept body- 

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

 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). 

 P/eiS<oce/ie.— Santa Barbara (Cooper): San Pedro (Arnold). 



( 37 ) April 28, 1903. 



