192 



with a fold on the anterior part, and short beaks. One or two hinge- 

 teeth and remote lateral teeth. 



The shells of this genus are chiefly known by the inflexion or irregular 

 fold on their fore part. The hinge-teeth are either one on each valve ; 

 two on one, and one on the other ; or two on each valve : and the late- 

 ral teeth are most frequently two, which are compressed. 



Lamarck particularizes the following, as being the species which are 

 found in the neighbourhood of Paris : T. patdlaris, much resembling 

 T. rcmies, Linri. T. scalaroides, T. carinulata, T. sinuata> T. donacialis t T. 

 rostralis, T. corneola, T. pusilla, T. rudis. 



The habitat of the rostrated shell represented Plate XIII. Fig. 4, I 

 am not acquainted with ; nor, though I have placed it here, am I satis- 

 fied of this being its most appropriate place, being entirely unacquainted 

 with its hinge. 



CXXI. Capsa. A transverse shell, with two cardinal teeth in one 

 valve, and one entering double tooth on the other. 



This genus is* exemplified by Venus deflorata, or Capsa rugosa, Linn. 

 List. Conch. Tab. 425, Fig. 273. The shells of this genus are not, I 

 believe, known fossil. 



CXXII. Solen. An equivalved, transversely elongated bivalve, gaping 

 on each side; the hinge-teeth single, in each valve, or double in one 

 valve ; the beaks exceedingly small ; the ligament external, and most 

 frequently near to the extremity of the shell. 



The wngumolari<z are distinguished from the Solcns by having two 

 hinge-teeth in each valve ; the glycemeres, by having no hinge-teeth ; and 

 the my&, by having an inner ligament, and by their projecting com- 

 pressed tooth in the left valve, to which the ligament is attached. 



Lamarck describes five fossil species of this genus, as found in the environs 

 of Paris : S. vagina, S.fragilis, S. ejfusus, S. strigilatus t S. appendiculatus. Of 

 S. vagina he remarks, that he found none more than three inches in their 

 transverse length. S.fragilis approaches very nearly to S. cultellus, Linn. 



