30 anomiidjE. 



tioned the modern use of the word. Poli 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 Argiope. There is 

 no visible trace of an epidermis. The plug of attach- 

 ment 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 mean time a short period 

 of liberty, like their relative the oyster. The Anomia* 

 are popularly designated 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 Iceland ; but fossil shells are 

 not uncommon at Uddevalla in the same bed which 

 contains Terebratella Spitzbergensis, Piliscus commochis, 

 and other forms of an extremely arctic kind. 



1. Anomia ephip'pium *, Linne. 



A. Ephippium, Linn. Syst. Nat. p. 1150 ; F. & H. ii. p. 325, pi. lv. f. 2, 3, 

 5, 7, and (animal) pi. T. f. 2. 



Body somewhat depressed, red, yellow, brown, or of all in- 

 termediate 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, cylindrical, and white, 

 sometimes curved and protruded from a slit in the shell above 

 the orifice, for the purpose of spinning a byssus and affording 

 an additional means of attachment. 



Shell round, oval, oblong, cylindrical, angular, or even 

 amorphous, compressed, and sometimes flattened, of different 

 degrees of thickness according to age, outside of a dull ap- 

 pearance, although the inner layers are remarkably glossy and 



* A horse-cloth. 



