160 



acuto, minutissime crenulato ; fornice costa transversal! antice 

 suffulto, fossam trigonalem utroque latere formante. Long. ^^, 

 lat. ^^jj, alt. ^% poll. Hab. Puget Sound. 



Differs from the preceding in shape, sculpture, and in the in- 

 terior rib, which props the fornix, and forms two pits, which, 

 with the fissure, remind one of the openings for the eyes and 

 nose in the human skull. 



Two small species of Eimula were found at Orange Harbor, 

 one of which is probably R. conica, D'Orb., and the other I name 

 R. coGNATA, which is similar to the preceding and to R. Noachina, 

 but more depressed. These were found living, and will be again 

 noticed when describing the animal. 



Crepidula rostriformis. Testa solida, Ijsevis, castanea, ele- 

 vata, recurva, ad basim rotundato-ovalis ; apice postico, adunco : 

 lamina interna parva, alba, profunde sita, versus apicem pene- 

 trans ; margine arcuatim sinuato. Long. J, lat. ^, alt. f poll. 

 Hab. Straits of De Fuca. 



I am acquainted with no other species where the apex is so 

 elevated and so remote from the margin of the shell. It looks 

 like a very obtuse-angled bird's-beak. The specimen examined 

 had numerous rib-like folds on the surface, which were probably 

 caused by its adhesion to some ribbed shell. 



Crepidula lingulata. Testa parva, depressa, obliqua, rotun- 

 data, alba, lineis numerosis crebre divaricantibus radiata, epider- 

 mide pallido induta ; apice acuto, libero, prope marginem sito : 

 intus lutescens ; septo linguiformi, excavato, ad medium carina 

 diviso et oblique protruso, ad latus sinistrum profunde sinuato. 

 Diam. ^, alt. f poll. Hab. Puget Sound. 



Like C. cajjensis, Quoy. The only specimen examined seems 

 to have been convex and solid in its early growth, afterwards 

 becoming flat. 



Crepidula ndmmaria. Testa tenuis, plana, circularis, alba, 

 striis incrementalibus laxis insculpta, epidcrmide flavo-cornea 

 induta ; apice vix conspicuo, marginali : septum internum latius 

 quam longum, deorsum fornicatum ; margine flexuoso : cavitas 

 fere nulla. Diam. ^ poll. Hab. Classet. 



This very peculiar shell is well characterized by its perfectly 

 flat, circular form. It probably grew within some other shell, 

 and other specimens may be found moulded into a different form. 

 It is separated from C. lingulata by the form of its septum. 



