28 



Family XXI.— SAXICAVID/C, Siva. 



Genus I. — Panopea, Menard cie la Groyc. 

 Panopea plicata, Mont. 



Genus II.— Saxicava, Fleur. 

 Saxicava norvegica, Spengl, 

 Saxicava rugosa, L. 



Saxicava rugosa, v arctica, L. 

 Saxicava rugosa, v minuta, L. 

 Saxicava rugosa, v praecisa, Mont. 

 Saxicava rugosa, v pholadis, Linn. 



Genus III. — Venerupsis, Lam. 

 Venerupsis irus, L. 



Family XXII.— GASTROCH/ENID/E, Gray. 



Genus Gastrochaena, Spengl. 

 Gastroch^ena dubia, Penn. 



Gastrochnena dubia, v ovalis, Jeff. 



Family XXIII.— PHOLADID/E, Gray. 

 Genus I. — Pholas, List. 

 Pholas dactylus, L. 



Pholas dactylus, v gracilis, Jeff. 

 Pholas dactylus, v decurtata, y^^ 



PHpLAS CANDIDA, L. 



Pholas Candida, v subovata,y^^ 

 Pholas parva, Penn. 



Pholas parva, v quadrangula, Jeff. 

 Pholas crispata, L. 



Genus II.— Pholadidea, GoodalL 

 Pholadidea papyracea, Turt. 



Pholadidea papyracea, v aborta,y"(f^ 



Genus III.— Xylophaga, Turt. 

 Xylophaga dorsalis, Turt. 



Family XXIV.— TEREDINID/E, iv'6v;/. 



Genus Teredo, Sellins. 

 Teredo norvegica, Speng. 



Teredo norvegica, v divaricata, Desh. 



