HALIOTIS. 85 



Var. kamtschatkana Jonas. PL 9, figs. 47, 49. 



Shell oval, rather depressed, rather thin ; surface with uneven 

 spiral cords, often almost obsolete, and strongly elevated undula- 

 tions or lumps ; color dull red, green, or red and green marbled. 

 Perforations elevated, 4 in number. Inside silver} 7 , very iridescent ; 

 columellar shelf narrow, flattened, sloping inward. 



Length 96, breadth 67, convexity 22 mill. 



Monterey, CaL, to Kamtschatka. 



Var. discus Eeeve. PI. 8. fig. 46. 



This is closely allied in all characters to the preceding, but more 

 elongated than the typical Kamtschatkana. The interior has a 

 peculiarly metallic luster, light bronze-green and coppery-red pre- 

 dominating. Length 120, width 78, convexity 25 mill. 



Japan. 



H. Sieboldii Reeve (pi. 15, figs. 78, 79) is in all probability a 

 monstrosity of H. gigantea. The single specimen known is in the 

 British museum. 



Group of H. tuberculata. 



Flattish, oval forms, having a tendency to develope coarse radiat- 

 ing wrinkles. The distribution is like that of the subgenus Bolma 

 of Astralium, — Japanese and Mediterranean Seas. 



H. tuberculata Linne. PI. 1, fig. 17 ; pi. 3, figs. 1, 2, 3. 



Shell long-oval, much depressed, spire submarginal ; spirally 

 striated and more or less wrinkled radiately ; holes about 6. 



The form is a regular oval, right and left sides about equally 

 curved ; it is depressed-convex above, having a slight ridge at the 

 row of holes, and a depression or shallow sulcus below it. The color 

 varies from light gray to reddish-brown spotted or mottled with red- 

 dish-brown, pale green, and often speckled with white; surface dull 

 and lusterless, covered with close, unequal spiral stria? and radiat- 

 ing growth-wrinkles. Spire low, 3 to 4 whorled, the distance of the 

 apex from the margin one-tenth to one-twelfth the length of shell. 

 Inside showing 1} whorls, nearly smooth, the muscle impression not 

 distinct ; the silvery nacre is brilliantly iridescent, with green, steel- 

 blue and red reflections ; lip-edge duller. Columellar plate flat, nar- 

 row, scarcely truncated at the base. Cavity of spire visible from 



