408 scrobiculaiiiinjk. 



and the siphonal tubes are equal, elongate, and separate as 

 far as their bases. The foot is large, oblong, compressed 

 and sub-angular anteriorly. 



Species of Galatea. 



Bengoensis, Dkr. rubicunda, Phil. 



lseta, Phil. tenuicula, Phil. 



paradoxa, Bom. versicolor, Morel. 



Sub-fam. SCROBICULARIIN^l. 



Siphons elongate, separate, diverging. 



Shell thin, sub-equivalve, gaping and often flexuous 

 posteriorly. Hinge with the cartilage internal, situated in 

 a cartilage-pit. 



Genus scrobicularia, Schumacher. 



Shell compressed, sub-equivalve, nearly smooth, or 

 marked by concentric grooves. Hinge with one or two 

 small, narrow primary teeth in each valve, and a spa- 

 thulate, triangular pit in each valve for the internal carti- 

 lage ; lateral teeth none ; ligament small, narrow, partially 

 external. Muscular impressions round ; pallial sinus 

 ample. 



Syn. Arenaria, Miihffeldt, not Linn. Ligula, Montagu. 

 Lavignonus, Ferns. Listera, Turt. Lutricola, Blainv. 

 Lutraria, Swains., not Lam. Calcinella, Desk. 



Ex. S. piperita, Gmelin, pi. 105, fig. 3. Shell, S. 

 piperita, fig. 3, a, 3, b. 



