MANUAL OF THE MOLLUSCA. 



One very common estuary shell rejoices in the following 

 variety of titles: 



Scrobicularia piperata (Gmelin sp). 



Trigonella plana (Da Costa). 



Mactra Listeri (Aucf). 



My a Hispanica (Chemnitz). 



Venus borealis (Pennant). 



Lutraria compressa (Lamarck). 



Arenaria plana (Megerle). 



As regards specific names, the earliest ought certainly to be 

 adopted, with, however, the following exceptions : 



1. MS. names; which are only admitted by courtesy. 



2. Names given by writers antecedent to Linnaeus. 



3. Names unaccompanied by a description or figure. 



4. Barbarisms; or names involving error or absurdity, * 



It is also very desirable that names having a general (Eu- 

 ropean) acceptation, should not be changed, on the discovery of 

 earlier names in obscure publications. 



With respect to genera, those who believe in their real ex- 

 istence, as " ideas of the creating mind," will be disposed to set 

 aside many random appellations, given to particular shells with- 

 out any clear enunciation of their characters ; and to adopt later 

 names, if bestowed with an accurate perception of the grounds 

 which entitle them to generic distinction.f 



Authority for specific names. The multiplication of syno- 

 nyms having made it desirable to place the authority after each 



* This subject was investigated, and reported upon, by a committee of the 

 British Association, in 1842 ; but the report was not sufficiently circulated. 



f Several bad practices against which there is, unhappily, no law 

 should be strongly discountenanced. First, the employment of names already 

 in familiar use for other objects ; such as cidaris (the title of a well-known 

 genus of sea-urchins), for a group of spiral shells ; and arenaria (a property of 

 the botanists), for a bivalve. Secondly, the conversion of specific into generic 

 titles, a process which has caused endless confusion ; it has arisen out of the 

 vain desire of giving new designations to old and familiar objects, and thus 

 obtaining a questionable sort of fame. 



