CONCHIFERA. 



239 



Anatina. Lam. (Auriscalpium Megerle ; Laterimla 

 Gray.) — Shell transverse, thin, 

 and almost transparent, gaping 

 at one or both ends, having a 

 spoon-shaped tooth in each valve 

 and a small moveable appendage 

 connected with the interior of 



Anatina. 



the hinge; the tooth in each 



valve is supported by a small thin plate ; ligament internal. 

 Animal having an entirely closed mantle as far as a small 

 front cleft forming an opening for the foot ; both siphons 

 are connected, and form a lengthened fleshy mass covered 

 by the epidermis, the entrance to them is contracted by 

 means of warty projections; both the gills on each side 

 are connected before, and free behind ; [according to Owen 

 there is on each side only one gill existing] on each side are 

 two mouth lobes ; the foot is small, and has at the end a 

 small round impression possibly serving as a sucker. — 10 

 species ; also fossil. 



These delicate shells are found in the Indian and 

 European seas, and those of New Holland and Africa, 

 Some of them are very rare and beautiful, and extremely 

 brittle. They are generally found in sands and shallow 

 waters. 



Philippi mentions as sub-genera Cercomya and Khyn- 

 chomya of Agassiz. 



Periploma. Solium. — Shell very thin, with the left 

 valve more ventricose than the right ; 

 hinge toothless ; ligament double, the 

 external portion thin, the internal 

 part thick, placed upon prominent, 

 sometimes spoon-shaped hinge laminae 

 and supported by a transverse bone ; 

 muscular impressions two, distinct ; 



*• Periploma. 



