232 lucixid^. 



Genus I. LO'RIPES * Poli. PL V. f. 4. 



Body somewhat compressed : mantle having the margin 

 notched : incurrent tube rather long and wrinkled : excurrent 

 tube sessile : foot awl-shaped. 



Shell almost equilateral, irregularly cancellated, or sculp- 

 tured by nexuous striae : lunule short : ligament (or rather the 

 cartilage) quite internal : teeth, one cardinal in the right, and 

 two in the left valve ; laterals remote and sometimes indistinct. 



The celebrated Neapolitan eonchologist, Poli,, who 

 founded this genus, described the shell under another 

 name — that of Loripoderma — a hybrid compound, or 

 " Babylonish dialect/' which fortunately we are not 

 obliged to use. It may be known from Lucina by the 

 different position of the ligament or cartilage, which is 

 external in that and internal in this genus. Deshayes 

 is of opinion that the structure of the ligament is of 

 more consequence than its position; but the structure 

 or composition of every kind of ligament or cartilage is 

 the same, and it appears to me that the position of this 

 apparatus deserves to be considered in any scheme of 

 classification. Any one character, if certain and not 

 liable to vary in the same genus, is as good as another 

 for this purpose. 



Searles Wood says that " this is a recent genus, and 

 its age, as far as it is known to me, does not extend 

 bevond the middle tertiaries." It is difficult to distin- 

 guish the genus Ungulina of Daudin from Loripes. Ac- 

 cording to Chenu, the ligament in Ungulina is external ; 

 but its exact position is in a groove on the hinge-plate, 

 within the dorsal margin. 



* So named from the thong-shaped foot. 



