406 PROCEEDTXGS OF THE NATIONAL MUSEUM. vol. xxvi. 



Indefatigable Island of the Galapagos group; a number of worn 

 valves. Cat. No. 102457, U.S.N. M. 



The young- shells appear to be oval, the only well-preserved adult 

 valve, which is figured, is distinctly cuneate. In general the species 

 is more elongate than the other species of the coast and the sculpture 

 is quite unlike any of the others, the nearest being C. columhiensis, 

 which has channeled and regular sulci between flat ribs. 



VENUS APODEMA, new species. 

 I'late XV, tig. S. 



Shell suborbicular, convex, white, concentrically ribbed with narrow, 

 solid, hardly elevated riblets separated by narrower sulci; beaks very 

 anterior, incurved, low, finely radiall}^ striated; anterior slope short 

 with a small cordate lunule; posterior slope arcuate, w^ith an elongated 

 area })ounded by a rounded ridge which does not interrupt the sculp- 

 ture; interior white, the margins with fine obscure crenulation; pallial 

 line with a short angular sinus; hinge normal, the corrugated area 

 small and narrow. Height, 43; length, 47; diameter, 2<S mm. 



Humboldt Bay, Gulf of Panama, Arthur Schott. Cat. No. 6243, 

 U.S.N.M. 



A single somewhat worn \'alve was collected by Schott with numer- 

 ous other beach shells, which he presented to the National Museum 

 nearh" fifty years ago. It has been named and figured, because of the 

 interest attaching to the discover}- of this genus in those waters, and 

 because it seems certain that it does not agree with any already known 

 species. It is very probable that the sculpture was considerably 

 sharper when the shell was fresh and the concentric sculpture unworn, 

 but it is evident that the latter never was sharph^ lamellar as in the 

 Atlantic species. 



MARCIA KENNERLEYI Reeve apud Carpenter. 

 Plate XIV, tig. 1. 



A figure of a specimen obtained alive in the harbor at Sitka, Alaska, 

 is included. Cat. No. 23441, U.S.N.M. 



A worn ^alve of this species was collected hy me at Carmel Bay, 

 near Monterey, California, in 1866. 



PAPHIA (PROTOTHACA) STAMINEA var. SULCULOSA. new species. 



Plate XIV, tig. 2. 



San Ignacio lagoon. Lower California; Henrv Hemphill. Cat, No. 

 105421, U.S.N.M. 



This form, through its modified sculpture, is so different from the 

 ordinary type that it seemed best to figure it. Only with a large series 

 can its relations to the type be fully appreciated. 



