186 ' 



7. Byssoarca decussata G, B. Sowerby. 



B. testa oblonga, alba, decussatim striata, epidermide 

 squamoso - setosa induta; latere antico breviore, superne sub- 

 angulato, postico superne rotundato-angulato, infra rotun- 

 dato; margine ventrali rectiuscula; area ligamenti angusta. 



Long. 2- poll., lat. 1- polL, alt. 1-2 poll. 



Legit H. Cuming testis meleagrinae margaritiferae Lam. 

 adhaerentem , ad littora insularum Oceani Pacilici (Lord 

 Hood's and Chain Islands). 



Proceedings. 1833. p. 18. 



8. Byssoarca illota G. B. Sowerhy. 



B. testa ovata, alba, radiatim costata, costis numero- 

 sis, decussatis; epiderpiide fusca, foliacea induta; latere an- 

 tico breviore, rotundato, postico declivi; area ligamenti an- 

 gusta, brevi. 



Long. 1*5 polL, lat. 075 polL, alt. 1* polL 



Legit H. Cuming sub Lipidibus in America centrali 

 (Gulf of Nocoiyo). 



Proceedings. 1833. p. 18. 



9. Byssoarca velata G. B. Sowerby. 



B. testa ovata, compressiuscula, radiatim costata et de- 

 cussata; dorso biangulato; epidermide fusca, squamosa, squa- 

 mis acuminatis; area ligamenti angusta. 



Long. 3'1 polL, lat. l*8polL, alt. 1' polL — Unum spe- 

 cimen pollices 6 longum est. 



Legit H. Cuming testis melcagrinae margariliferae Lam. 

 adliaerentem, ad littora insularum Oceani Pacifici (Lord 

 Hood's and Chain IsLinds). 



Proceedings. 1833. p. 18. 



10. Byssoarca solida G. B. Sowerby. 



B. testa ovato-quadrata, crassa, solida, aequilaterali, 

 radiatim striata, minutissime decussata; latcre antico rotmi- 

 dato, poslico superne obtusc angulato, obsolete carinato; 

 area ligamenti elongata, ligamcnto rhomboideo, centrali. 



Long. 0-6 polL, lat. 05 polL, alt. 0-4 polL 



