HELCIONISCUS. 133 



cone. The apex is at the front I of the length. The interior shows 

 fine transverse wrinkles when examined under a lens. It is not 

 especially iridescent except at the border, where there is a narrow 

 strip of fiery-orange iridescence between the blue-white of the interior 

 and the blackish stained border. The species is named in honor of 

 Mr. Frederick Stearns of Detroit, Michigan, who collected the shells 

 when traveling in Japan. 



H. PALLIDUS Gould. PL 67, figs. 9, 10. 



Shell subovate, elevated, erectly-conical, solid ; white both out- 

 side and within, or whitish-yellow ; having close concentric sulci and 

 strise, and radiating unequal ribs, the ribs plicate or obsoletely 

 plicate-tuberculate ; there are 20-25 larger ribs radiating from the 

 summit itself; of the smaller interstitial riblets there are about 60. 

 Apex subcentral or at the front f of the length. Margin of the 

 aperture undulating. (Schrenck.^) 



Length 40, breadth 33, alt. 24 mill. 



Length 60, breadth 51, alt. 29 mill. 



Hakodadi, Japan. 



P. pallida GOULD, Proc. Bost. Soc. N. H. vii, p. 162. DKR., Ind. 

 Moll. Mar. Jap., p. 156. P. lamanonii SCHRENCK, Reisen und 

 Forsch. im Amurl. ii, p. 303, t. 14, f. 6-9. 



Characterized by its light color and the sculpture, consisting of 

 radiating ribs, and having several riblets in each interval. I have 

 seen none but immature specimens. 



H. NIGROLINEATUS Reeve. PL 14, figs. 71, 72, 73, 74 ; pi. 13, figs. 



48, 49. 



Shell solid, oval, rather depressed ; apex at the front third ; slopes 

 slightly convex; surface nearly smooth, the young having sub- 

 obsolete radiating riblets ; bluish, with numerous narrow radiating 

 stripes of red, or sometimes black. 



Interior dark-silvery, showing (especially in young shells) black 

 radiating stripes. Central callus bright orange-red, veined with black, 

 its front portion white or nearly so. 



Length 74, breadth 60, alt. 18 mill. 



Enoshima (Fr. Stearns), Nagasaki (Lischke) and Tsus-sima (Ad.), 

 Japan; Camiguan, Philippines (Rve.) 



P. nigrolineata REEVE, Conch. Icon., f. 43. LISCHKE, Jap. 

 Meeres-Conchyl. i, p. Ill, t. 8, f. 5-11 ; ii, p. 103, t. 7, f. 1-6. 



