80 HALIOTIS. 



A well-known and abundant species, peculiar in its uniform 

 blackish color and numerous small perforations. The muscle 

 attachment is usually smooth, but specimens occur having a small 

 roughened area there. The largest shejls I have seen of this species 

 have a length of about 160 mill. 



The H. calif ornien sis of Swainson is a specimen with more numer- 

 ous perforations than the type. It can scarcely be separated varie- 

 tally. 



Group of H. corrugata. 



These shells are eminently characteristic of the western coast of 

 America, all of the species of that region except H. cracherodii 

 grouping here. The group comprises most of the large species of 

 Haliotis, and the two largest (gigantea and rufeseens). One species, 

 (ff. gigantea) exhibiting numerous diverging varieties and forms is 

 found in Japanese waters. 



H. CORRUGATA Gray. PL 5, fig. 24. 



Shell large, subcircular or short oval, very convex, like a half- 

 globe ; surface corrugated all over, the wrinkles nodose ; perfora- 

 tions elevated, tubular, three open ; inside dark, very brilliantly iri- 

 descent, muscle scar distinct, roughened. 



The outline is more rounded than usual, being a very short oval ; 

 the back is very convex. The strong epidermis is dull, olive-brown 

 usually having wide oblique greenish intervals ; the sculpture be- 

 gins as crowded spiral cords or lirse, but over the greater part of 

 the body- whorl these become nodose at short intervals, or are crossed 

 by obliquely radiating corrugations. It is angled at the row of 

 holes ; below these there is a distinct spiral channel or furrow, 

 bounded below by a more or less distinct row of nodules ; and be- 

 tween this and the columellar margin it is obliquely corrugated, the 

 folds scalloping the lower part of the columellar margin. The spire 

 does not project above the general outline of the shell. Inside it is 

 dark, iridescent, red predominating in the coloration. The muscle 

 impression is large, distinct, roughened all over, and like fine 

 mosaic work in its brilliant coloration. The flat or concave colu- 

 mellar plate slopes strongly inward, and is not at all truncate at the 

 base; above it almost conceals the small cavity of the spire. The 

 large tubular perforations are sometimes two, but normally three in 

 number. Length 155, width 122, convexity 57 mill. 



San Diego, CaL, southward ; Catalina Island. 



H. corrugata GRAY in Wood's Index Test. Suppl., t. 8, f. 5. 

 REEVE Conch. Icon., f. 12. Sows. Thes. Conch., t. 4, f. 26 (excL 

 V ar.). WEINKAUFF, Conchyl. Cab., p. 67 t, 25, 26. KEEP, West 



