420 MOLLUSC A. 



Some of them are found in the sand at the mouths of rivers 

 in France(l). In the 



Mya, Lam., 



Or the Mya properly so called, one valve is furnished with a 

 plate which projects into the other, and this latter with a cavity. 

 The ligament stretches from this cavity to that plate. 



Some species are found in the sand along the coast of 



France(2). 



Anatina, Lam. 



The Anatinse of Lamarck should be approximated to the preceding 

 Myse. Each of their valves has a small projecting plate inside with 

 the ligament extending from one to the other. 



One oblong and excessively thin species is known, the valves 

 of which are supported by an internal ridge(3); and another of 

 a squarer form without the ridge(4). In the 



SoLEMYA, Lam. 



The ligament is seen on the outside of the shell, part of it re- 

 maining attached to a horizontal internal cuilleron on each valve. 

 There is no other cardinal tooth, and a thick epidermis projects 

 beyond the edges of the shell. 



One species, the Tellina togata, Poli, II, xv, 20, is found in 

 the Mediterranean(5). 



Glycymeris, Lam. Cyrtodaria, Daud. 



Neither teeth, plates, nor cavities on the hinge, but a simple cal- 

 lous enlargement, behind which is an external ligament. The ani- 

 mal resembles that of the Myse. 



The most common species Myasiliqua, L.; Chemn. XI, 193, 

 f. 194, is from the Arctic Ocean. 



(1) Madra lutraria, List., 415, 259; Chemn., VI, xxiv, 240, 241; Mya oUonga, 

 Id., lb., ii, 12;Acosta, Brit. Conch., XVII, 4; Gualt., 90, A, fig-, min. 



(2) Myatruncata, L., Chemn., VI, i, 1, 2; M. arenaria, lb., 3, 4. 



(3) Solen anatinus, Chemn., VI, vi, 46 48. 



(4) Encyc, 230, 6, under the name of Corbule,- An. hispidula, Cuv., An. sans 

 vert., Egyp. Coq. pi. vii, f. 8. I suspect that the Rupicoi.^ of F. de Bellevue 

 (Voy. Roissy, VI, 440) must approach this subgenus. They live in the interior of 

 stones, like the Petricolx, Pholades, &c. 



(5) New-Holland furnishes a second species, the Sol. australis, Lam. 



