HIPPONYX.' 135 



H. BARBATUS, Sowb. PL 40, figs. 2, 3. 



Shell depressed, apex suberect, subposterior, whitish, concen- 

 trically and rat! lately striated, with a pilose brownish epidermis, 

 aperture margin smooth. Length, *75 inch. 



Mazallan, Galapagos Is., Polynesia, Japan, 



Cape Good Hope. 



It is H. australis, Menke, not Lam. H. pilosus, Desh. (fig. 3), 

 appears to be the same, and has priority, but the species is gen- 

 erally known as H. barbatus. 



H. GRAYANUS, Menke. PI. 40, figs. 4, 5. 



Apex subcentral, ribs fewer, coarser and more nodulous than 

 in H. barbatus, with softer, shorter, fewer and more irregular 

 hairs, base flat but verj r broad, rather rounded at the inner 

 margin, cren a ted at the outer, with numerous lamellae, undulated 

 but not serrated. Length, *75 inch. 



Galapagos, Panama, Mazatlan, Sandwich Islands. 



Described as H. radiatus, Gray, a name preoccupied by Quoy 

 and Gaimard, and by Desha3 T es, the latter for a fossil species. I 

 doubt its distinctness from H. barbatus. 



H. CRANIOIDES, Carp. PL 40, figs. 6, 7. 



Rounded, convexly planate, the apex subcentral, radiately 

 striate, concentrically laminate. Length, '85 inch. 



Vancouver' ' Island. 



H. lumens, Carp. (fig. 7\ is a somewhat higher form, less 

 worn by attrition, but having the essential characters of the 

 above ; it is reported from Sta. Barbara and S. Pedro, Cal. 

 Neither species has very good claims to recognition as distinct. 



H. RADIATUS, Quoy and Gaimard. PL 41, fig. 8. 



Shell radiateh" broadly costate, apex snbmedian. Dimensions 

 and habitat unknown. 



This species was found on a Pterocera chiragra, consequently 

 is probably Polynesian. The figure is no doubt magnified, but 

 the dimensions are not given. It appears to me not unlike H. 

 auslralis, Quoy. 



