1^2 OYSTERS, AND ALL ABOUT THEM. 



Anomia thus restricted, and long custom has sanctioned 

 the modern use of the word. Poll proposed the name of 

 Echion for the animal of the present genus. 



According to Dr. Carpenter, the outer layer of the 

 shell has a prismatic cellular structure, and in this respect 

 it appears to resemble the shell of the Argiope. There is 

 no visible trace of an epidermis. The plug of attachment 

 is secreted by that part of the adductor muscle which 

 passes through the lower valve. It is not shelly. The fry 

 are fixed in the same way as the adult, soon after their 

 exclusion from the ovary : although it would appear that 

 they enjoy in the meantime a short period of liberty, like 

 their relative the oyster. The Anomia are popularly desig- 

 nated in this country "silver-shells." In the State of New 

 York they are called "jingle-shells." Dr. Otto Torell 

 informs me that no species has been found north of Ice- 

 land ; but fossil shells are not uncommon at Uddevalla, in 

 the same bed which contains Terebratella Spitzbergensis, 

 Piliscus commodus, and other forms of an extremely 

 arctic kind. 



i. ANOMIA EPHIPPIUM. Linne. 



A. Ephippium, Linnaeus. Syst. Nat., p. 1150; Forbes & 



Hanley, 2. p. 325. 



BODY somewhat depressed, red, yellow, brown, or of 

 all intermediate shades of those colours : mantle circular : 

 cirri or tentacular filaments arranged in two or three rows, 

 ciliated or feathered, yellowish-white : mouth large, with a 

 pair of long delicate lips on each side : foot short, cylin- 

 drical, and white, sometimes curved and protruded from a 

 slit in the shell above the orifice, for the purpose of spin- 

 ning a byssus and affording an additional means of attach- 

 ment. 



