48 MANUAL OF THE MOLLUSCA. 
NOMENCLATURE. 
The practice of using two names—generic and specific—for 
each animal, or plant, originated with Linnzeus; therefore no 
scientific names date further back than his works. In the con- 
struction of these names the Greek and Latin languages are 
preferred by the common consent of all countries. 
Synonyms. It often happens that a species is named, or a 
genus established, by more than one person, at different times, 
and in ignorance of each other’s labours. Such duplicate names 
are called synonyms ; they have multiplied amazingly of late, 
and are a stumbling-block and an opprobrium in all branches 
of natural history.* 
One very common estuary shell rejoices in the following 
variety of titles :— 
Scrobicularia piperata (Gmelin sp.). 
Trigonella plana (Da Costa). 
Mactra Listeri (Awct.). 
Mya Hispanica (Chemnitz). 
Venus borealis (Pennant). 
Lutraria compressa (Lamarck). 
Arenaria plana (MMegerle). 
As regards specific names, the earliest ought certainly to be 
adopted, with, however, the following exceptions :— 
1. MS. names; which are admitted by courtesy. 
2. Names given by writers antecedent to Linnzeus. 
3. Names unaccompanied by a description or figure. 
4, Barbarisms; or names involving error or absurdity.+ 
It is also very desirable that names haying a general (Huro- 
pean) acceptation should not be changed on the discovery of 
earlier names in obscure publications. - 
emblem of eternity—the serpent holding its tail in its mouth. The following diagram 
is offered as an improved circular system :— 
[ FISHES. } 
Di-branchiata, 
Nucleo- Tetra- ° 
Opistho- Proso- 
Aporo- Pulmo- 
Pallio- Lamelli- 
Hetero-branchiata. 
[ZOOPHYTES. } 
* In Pfeiffex’s Monograph of the Helicide, a family containing seventeen genera, 
no less than 330 generc synonyms are enumerated ; to this list Dr. Albers, of Berlin, 
has added another hundred of his own invention! 
7 This subject was investigated and reported upon by a committee of the British 
Agsociation in 1842. 
