214 MACRON. 



Genus MACRON, H. and A. Adams. 



This was originally described as a subgenus of Pseudoliva, 

 which it resembles in having an inferior revolving groove ter- 

 minating in a small tooth-like projection of the outer lip ; the 

 operculum, however, is unguiculate like that of the Eburme, 

 whilst that of Pseudoliva is purpuroid. The more decided canal 

 and absence of sutural channel, and the rather persistent black- 

 ish brown epidermis, will distinguish it from the subgenus % emir a 

 of Eburna. Its locality, West Coast of North America, is also 

 a distinctive character ; Eburna being East Indian, and Pseudo- 

 liva African in distribution. The species are partly included in 

 Sowerby's monograph of Pseudoliva in Thesaurus Conch., 

 Vol. III. 



M. KELLETTII, A. Adams. PL 82, fig. 4T7. 



Epidermis blackish or dark brown, under which the shell is 

 white. Whorls partially or entirely encircled with low, broad, 

 rounded ribs, sometimes only apparent on the lower part of the 

 body whorl, sometimes obsolete. Length, 1-T5 to 3 inches. 



San Diego, Gal.; Gulf of California. 



Buccinum ^Ethiops, Reeve, has been confounded with this 

 species, but is a very different shell, entirely distinct in its over- 

 hanging ribs, broad flat shoulder, want of tooth on the lip, etc. ; 

 in fact is a synonym of Purpura cingulata, Linn. M. Kellettii. 

 Hinds, belongs to the genus Siphonalia. 



M. LIVI.DA, A. Adams. PI. 82, fig. 478. 



Epidermis dark brown, whitish or livid beneath ; surface 

 smooth except several incised stride near the base. 



Length, 20 mill. 



San Diego, Cal.; Todas Santos Bay, L. Gal. 



Mr. Stearns thinks this will prove to be a small form of M. 

 Kellettii, dwarfed by reason of its northern habitat. Its perfect 

 growth, narrower form, much smaller size, and thick lip indicate 

 to me adult specimens of a distinct species. 



M. WBIGHTII, H. Ad. Coast of Patagonia. 



M. COMMODA, H. and A. Ad. Hab. unknown. 



Neither of these species has been figured. 



