AKNOLD-THE PALEONTOLOGY AND STKATIGRAPHY OF SAN PEDHO. 241 



iiiul at bath-house, Santa Barbara. The specimen figurctl is from the upper San 

 Pedro series at Sau Pedro, and is now in tlie collection of Delos Arnold. 



Living. — Neah Bay to San Diego (Cooper). 



Pkiatocene. — Santa Barbara to San Pedro (Cooper): Sun Pedro; San Diego; 

 Santa Barbara (Arnold). 



Pliocene. — San Diego well (Dall). 



Genus Amphissa //. it A. Adams. 



Shell bucciniform, longitudinally ribbed; spire elevated; aperture rather wide, enlarging 

 below, and terminating in a wide anterior sinus; inner lip callous, plicate below; outer lip not thickened 

 on margin, plicate within. 



Amphissa corrugata Reeve is a characteristic species. 



235. Amphissa corrugata Reeve. 



Bucciiium corrugatum RvE., Icon. Conch., PI. IV, fig. no, 1846. 



Truncaria corrugata RvE., Cpr., Brit. Assn. Rept., 1863, p. 662. 



Cominella {Amphissa) corrugata RvE., Cpr., Brit. Assn. Rept., 1866. Gabb, Pal. Cal., Vol. II, 



p. 74, 1869. 

 Amphissa corrugata RvE., Tryon, Man. Conch., Vol. V, p. 197, PI. LXIII, fig. 66, 1883. 

 Cooper, 7th Ann. Rept. Cal. St. Min., 18S8, p. 228. Keep, West Coast Shells, 

 P- 34. fig- 14. 1892. 

 Shell small, solid, fusiform; spire elevated; ape.x acute; whorls seven, slightly convex, with 

 about eighteen to twenty rather wavy, slightly oblique, rounded, transverse ridges extending from 

 suture to suture; spiral ornamentation consists of numerous fine, raised lines in the interspaces 

 between the transverse ridges; suture impressed, distinct; aperture rhomboidal, narrow; outer lip 

 lirate within; inner lip incru.sted, smooth; canal short, recurved; pillar spirally lined externally. 



Dimensions. — Long. 19 mm.; lat. 9 mm.; body-whorl 13.5 mm.; aperture 10 mm.; defl. 

 52 degrees. 



The Pliocene forms are much smaller than the one described above (a Pleisto- 

 cene specimen). Carpenter mentions the shells as becoming dwarfed in deep water 

 (40 fathoms). 



Rather common in Pliocene and lower San Pedro series at Deadraan Island; 

 rare in upper San Pedro series at San Pedro, Los Cerritos, and Crawfish George's. 

 Found also in the Pleistocene at the bath-house, Santa Barbara. 



Living. — Alaska to San Diego (Cooper). 



Pleistocene. — Santa Barbara to San Diego (Cooper): San Pedro; Santa Bar- 

 bara (Arnold). 



Pliocene.— i^an Diego well (Dall): San Pedro (Arnold). 



( 31, March 21, lOOa. 



