362 Dr. Turton on some new British Shells. 



Shell bivalve, equivalve, equilateral, transverse; with a large 

 oval gape at the front margin. Hinge without teeth. Ligament 

 internal. 



Length two lines and a half; breadth not quite half an inch. 



This new and very singular bivalve, we dredged up in the Eng- 

 lish Channel, alive, during a gale of wind. The shell is very tumid 

 in the middle, and gradually sloping to the sides, which are 

 rounded and closed. The colour is of a dull milky white ; and 

 the surface covered with short, close-set, transverse, interrupted, 

 opake lines, very irregularly disposed, and which give the margin 

 a serrated appearance. The beaks are rather prominent and cen- 

 tral ; the cardinal margin running nearly straight ; but the front 

 margin a little rounded, with a large oval eye-like transverse gape, 

 extending the whole breadth. 



In the Linnean arrangement it would rank with the Myce. 

 Dr. Goodall, who carefully examined our specimen, thinks he has 

 somewhere seen a single valve, which from the peculiar markings 

 of the surface, cannot be mistaken for any other known shell. 



Icon. tab. xiii. fig. 1. 



Mus. nost. 



2. Lima tenera. 



Tesid compressdf incequilateralt, utrinque hiante ; latere antico 

 subtrigono, peritremate intus marginato : costis^S; subun- 

 datiSf IcBviusculis f margine serrato; car dine obliquo. 



Shell compressed, inequilateral, open on both sides; the an- 

 terior side somewhat triangular, with the aperture margined in- 

 ternally : ribs 25, somewhat undulated, and nearly smooth : the 

 margin serrated ; and the hinge oblique. 



Length an inch ; breadth five eighths of an inch. 



This shell does not seem to agree exactly with any of the 

 species described by authors. It differs from the Lima Loxcombi, 

 our L. bullata^ in being much more depressed ; in having fewer 



forms us that he has two other species, one from the Mauritius and the other 

 from Van Diemen's Land; it is therefore necessary that a specific name should 

 be given to this species, and we have chosen Turtoni, in honour of the first 

 descrjber of the genus. — Editors. 



