178 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.37. 



FISSURELLA PERUVIANA Lamarck. 



Fissurella peruviana Lamarck, Anim. s. Vert., vol. 7, 1822, pt. 2, p. 15 (not oi 

 Delessert, Rec, pi. 24, fig. 7). — Reeve, Conch. Icon., 1849, Fissurella, 

 fig. 26. 

 Lapa. Dredged in Callao Harbor on the northeast side of San Lorenzo Island, 

 in 2 J fathoms. 



Distribution. — The whole Peruvian province. 



Shell rounded oval, elevated, conical, the foramen small, a little 

 in advance of the middle; radiately finely striated; inside white, the 

 margin alternately red and gray; outside red toward the summit, 

 becoming more purple and darker toward the base; the margin is 

 smooth, with a dark border inside, the exterior rayed with dark 

 purple. Length about 30 mm. 



This is the F. occidens of Gould. 



MEGATEBENNUS COKERI, new species. 

 Plate 24, figs. 3, 7. 

 Lobos de Afuera Island, on beach. 



Shell ovate, narrower in front, solid, heavy, steep sided, anterior 

 slope shorter, sharply radially sulcate, the interspaces flattish, feebly 

 rounded, not uniform in width; lines of growth looped toward the 

 apex over the interspaces; color greenish white toward the base, 

 reddish purple toward the apex, with sparse rays of the latter color; 

 foramen large, keyhole shaped, with a greenish margin; length of 

 foramen at the outer margin nearly one-third of the total length of 

 the shell; interior greenish white, with a polished, greenish, radiately 

 striate margin to the foramen; margin of the base smooth, entire, 

 extended for a narrow space over the exterior edge. The type 

 (Cat. No. 207744, U.S.N.M.) measures: Length of shell 27.5; of outer 

 edge of foramen 9.0; of inner edge of same 6.0; of foraminal inside 

 margin 11.0; maximum width of shell at the posterior edge of the 

 above margin 16.5; at the anterior edge of the above margin 14.0; 

 height of the shell 10.0 mm. 



This species unquestionably belongs to Pilsbry's section Amhly- 

 chilepas, which was supposed to be wholly old world in its distribu- 

 tion. It much resembles M. scutellum (Gmelin) Pilsbry, but is 

 darker toward the summit and lighter toward the base, while in the 

 Cape of Good Hope species the reverse coloration obtains. 



Named for Mr. R. E. Coker. 



ACM.ffiA VIRIDULA Lamarck. 

 Plate 24, figs. 1, 2. 

 Patella riridula Lamarck, Anim. s. Vert., vol. 7, 1822, p. 539. — Delessert, 



Rec. Coq., pi. 23, fig. 2. 

 Acmsea pretrei Orbigny, Voy. Am. Mer., vol. 5, 1841, p. 481, \)\. 78, figs. 15-16. 

 Patela. From rocky shore on the northeast side of San Lorenzo Island, Callao 

 Bay; similar stations on Lobos de Afuera Island; the Pescadores Islands; Sechura 



