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CONCHOLOGY. 



Lutraria solenoides. 

 L. rugosa. 

 L. compressa. 

 L. piperata. 

 L. tellinoides. 



Lutraria ellipiica. 

 L. papyracea. 

 L. Plicatella. 

 L. crassiplica. 

 L. complanata. 



L. Candida. 



2. Genus JUactra. 



Atiwial. Body oval and pretty thick ; edges of the mantle 

 thick, smooth, or without tentacular papillse, augmented behind 

 by two indistinct tubes ; mouth small and oval ; labial appendages 

 narrow ; branchial laminae very small, and united in their length 

 among themselves and with those of the opposite side ; foot oval, 

 trenchant, very long. 



Shell. The Mactra has a peculiar hinge distinguishing it from 

 all other genera. It is triangular, with a curved or angular 

 compressed tooth on each valve, with a small oblique cavity on 

 each side, to which is attached the ligament. Two lateral teeth, 

 one near the primary tooth and one near the ligament. The shape 

 of the shell is subtriangular or oblong ; exterior smooth, striated, or 

 ribbed transversely ; two muscular impressions united by a narrow 

 marginal tongue. Inhabits the British coasts. Thirty-four 

 species. 



Mactra gigantea. 

 M. spengleri. 

 M. striatella. 

 M. carinata. 

 M. straminea. 

 M. Australis. 

 M. violacea. 

 M. fasciata. 

 M. turgida. 

 M. plicataria. 

 M. rufescens. 

 M. maculata. 

 M. subplicata. 

 M. triangularis. 



Mactra helvacea. 

 M. grandis. 

 M. stultorum. 

 M. maculosa. 

 M. ovalina. 

 M. alba. 

 M. solida. 

 M. castanea. 

 M. rufa. 

 M. squalida. 

 M. brasiliana. 

 M. donacina. 

 M. depressa. 

 M. lilacea. 



