186 BIVALVES. 



lour of this genus is a dingy yellow, or dusky 

 white; the shells are generally thin, fragile, 

 delicate, and would be ill-fitted to contend with 

 the dangers of their dwelling in the boisterous 

 ocean, had not He who placed them amidst its 

 perils, exercised his compensatory providence, 

 and anchored them securely in its depths. The 

 animal belonging to the shells, is very similar to 

 the oyster. 



The other family of this genus now bears the 

 name of Terebratula. The shells which it con- 

 tains, are distinguished by the graceful elegance 

 of their form, which resembles a Grecian lamp, 

 and from hence they are called the Antique 

 Lamps. The concave valve of the Terebratula 

 has its beak produced, curved over the other 

 valve, and perforated at the apex ; the smaller 

 valve is furnished with two slender shelly pro- 

 cesses, which are sometimes short, simple, and 

 recurved ; sometimes long, branching and cross- 

 ing each other ; their use is not ascertained, but 

 it is supposed that they are supports for the ani- 

 mal. The Terebratulae inhabit the depths of 

 the ocean ; they are parasitical, and are attached 

 to various submarine substances by a tough short 

 stalk which differs from the ligament of the 

 Anomia in being formed of numerous closely 

 united fibres, separating a little at the end, by 

 which they are fixed. The mollusk which in- 

 habits this shell is remarkable for two long 

 fringed arms, rolled up in a spiral form within 

 the shell when at rest, but which it protrudes 

 when hunger prompts it to seek for food. 



