242 CALIFOENIA ACADEMY OF SCIENCES. 



236. Amphissa ventricosa, sp. nov. 



Plate V, Fig. 11. 



Shell small, broadly fusiform; spire elevated; whorls five or six, evenly conve.x, with twelve 

 or thirteen strong, rounded, transverse ridges; interspaces sculptured with prominent, regular, equi- 

 distant, raised spiral lines, of which there are five or si,x on the penultimate whorl; suture deeply 

 impressed, distinct; aperture semicircular; outer lip ventricose, thickened with row of teeth; inner 

 lip smooth, incrusted; pillar straight; spirally sculptured on outside; no canal. 



Dtme7isions. — Long. 12 mm.; lat. 6 mm.; body-whorl 8.6 mm.; aperture 6 mm.; defl. 

 43 degrees. 



Resembles A. hicolor somewhat, but distinguishable from this species by lack of 

 canal, stronger ribs, and more convex whorls; distinguishable from other members 

 of genus by thin shell, ventricose whorls, semicircular aperture and lack of differ- 

 entiated canal. Dr. Dall examined the type and pronounced it a new species. 



Rare in lower San Pedro series of Deadman Island. The specimen figured 

 is the type, which is from the lower San Pedro series at Deadman Island, and is now 

 in the United States National Museum. 



Pleistocene. — San Pedro (Arnold). 



237. Amphissa versicolor Dull. 



Amphissa versicolor Dall, Am. Jour. Conch., Vol. VII, 1872, p. iii. Tryon, Man. Conch., 

 Vol. V, p. 197, PI. LXIII, fig. 67, 1883; Proc. U. S. Nat. Mus., Vol. XV, 1892, 

 p. 213, PI. XX, fig. 9. 



Amphissa corrugata RvE., Cooper, 7th Ann. Rept. Cal. St. Min., 1888, p. 228 (in part). 



Shell small, fusiform; apex acute; whorls seven, convex, slightly angular above; body-whorl 

 slightly ventricose; surface ornamented with about fourteen rounded, obliquely transverse ridges, and 

 several distinct, raised, spiral lines in the interspaces; suture quite deeply impressed; aperture sub- 

 elliptical; outer lip slightly thickened by lirated ridges on inner side; inner lip incrusted, smooth; 

 columella spirally sculptured externally; canal short, broad, recurved. 



Dimensions. — -Long. 10.2 mm.; lat. 5 mm.; body-whorl 7 mm.; aperture 5 mm.; defl. 

 47 degrees. 



Distinguishable from A. corrugata by more ventricose body-whorl, relatively 

 longer columella and shorter sjiire, more angulated whorls, deeper suture and less 

 numerous but more oblique and larger transverse ridges. Specimen identified by 

 Dr. Dall. 



Found in lower San Pedro series at Deadman Island, and u])per San Pedro 

 series at Crawfish George's, Los Cerritos, and Deadman Island. Found also in the 

 Pleistocene at Pacific Beach, San Diego. 



Living. — San Pedro (Dall). 



Pleistocene. — San Pedro; San Diego (Arnold). 



