CONCHIFERA. 



303 



without spirit; but they are principally remarkable for 

 being almost identical with a similar engraved shell found 

 in an Etruscan tomb, and now in the British Museum. 

 This is not the only instance of relics from Assyria and 

 Etruria being of the same character, showing a close 

 connection between the two countries, either direct, or by 

 mutual intercourse with some intermediate nation." 



Hippopus. Lam. (Tridacna Gray.) — Shell equivalve, 

 regular, inequilateral ; valves 

 closed, transverse, two com- 

 pressed teeth in each valve ; 

 ligament external ; shell im- 

 bricated with numerous tu- 

 bercles. Animal similar to 

 that of the Tridacna, except 

 that the foot is small, and 

 there is no byssus. — 1 spe- 

 cies. 



This handsome shell is not 



Hippopus maculatus. 



nearly so large as the Tri- 

 dacna, and is common in collections, although there is but 

 one species — H. maculatus, from the Indian Ocean. 

 Sowerby justly remarks : — " The delicate whiteness of the 

 interior, the undulating edges, the radiated fluted columns, 

 adorned at intervals by crisped fringes, and the richness 

 of the variegated colouring, are such as to secure the 

 admiration of the most superficial observer." 



Family 2. — MALLEA CEA. 



The animal is nearly united to the Pinna, but it has 

 only one central fastening muscle. The other particulars 

 are, that the two mantle lobes are separated in their whole 



