PECTINID 2. 45 
A. fornicata and A. coronata recorded by Mr. Bean, but I 
learn from the ‘ British Mollusca’ that they fall into the same 
category with those I have named. 
I have now noticed all the varieties of A. ephippium termed 
by authors species, and there is certainly no sculpture on 
them of such a decided character as to denote specific distinc- 
tion; therefore all the markings, shapes and colours of this 
Protean genus being inadequate for the foundation of species, 
we must have recourse to our sheet-anchor—the malacology 
of the animal—to assist our determinations; and after the 
examination of a great number of individuals, of nearly all 
the recorded species, we have come to the conclusion that 
they are varieties of the only British one of this genus, the 
A. ephippium, which, by the identity of its organs with the 
pseudo-species, puts a veto on a longer continuance of the 
dismemberment of its unity, by allowmg forms based on mere 
varietal distinction to march pari passu with it, and which 
have no solid grounds for aspiring to higher honours. 
PECTINIDA. 
The British Pectinide comprise only the genus Pecten, 
which is a part of Lamarck’s monomyal order. The genus 
Lima, usually associated with Pecten, is merged in it as a 
section. Our reasons for distributing the Anomie, Pectines, 
and Ostree in three families, are given in our remarks on 
the Anomiade, where the essential points of the differences 
of the organs and habitudes of their animals are shown; we 
may add, that the texture of the shells of this group has lost 
the leafy imbricated character and become firmer, solid, and 
of a more porcellanous nature; their form is infinitely more 
symmetrical than in either Anomia or Ostrea. A careful 
examination of the descriptive notes of the animals of the 
Pectinide will show that they are not of the same family as 
either of the other groups. 
