308 Lamarck’s Genera of Shells. 
mactre, lucinz, tellinee, corbes, andcyclades. The ligament of 
the donaces and the tellinz, is always on the shortest side of thie 
shell, but in the yeneres and cythere itis on the longest. The 
donax has not the flexuous fold of the tellina. 
The donaces are marine shore shells, smooth, or finely 
striated, and often decorated with lively and agreeable colours. 
Type. Donax scortum*. (Idem. Linn.) 
Shell triangular, anteriorly acute; decussately striated ; 
corselet cordate, flat; margins nearly smooth. Indian Ocean. 
27 Species. Pl. v. Fig. 49. 
6. Capsaf. 
Shell transverse, equivalve, close. Hinge with two teeth on 
the right valve; only one bifid, entering tooth on the other. 
No lateral teeth. Ligament,external. 
The capse are rather inequilateral shells, with the ligament 
on the short side, like the telline and donaces. They are al- 
lied to the psammobix, and certain telline, by their cardinal 
teeth, but they scarcely gape at all at the sides, and have not 
the flexuous fold of the telline. 
Type. Capsalevigatat. (Donax levigata. Gmelin.) 
Shell triangular, subequilateral, obsoletely striated; epi- 
dermis greenish yellow; internally, and at the nates, violet 
coloured. Tranquebar. 2 Species. Pl. v. Fig. 50. 
7. Crassina §. 
Shell suborbicular, transverse, equivalve, subinequilateral, 
close. Two strong diverging cardinal teeth on the right valve, 
and two very unequal teeth on the other. Ligament on the 
longest side, external. 
The crassina resembles a small crassatella; both in appear- 
ance, and in the thickness, solidity, and perfect closeness of 
the valves when shut, but it differs from them by the position 
of the ligament. It is distinguished from the venus by having 
only two teeth on each valve, those on the left even appearing 
* The skin of a beast ; also a harlot. + A coffer, or box. 
t+ Smoothed. 5 From crassus, thick. 
