NOMENCLATURE. 59 



ment on a plane surface would fail, for the affinities radiate in 

 all directions, and tlie " net-work" to which Fabricius likened 

 them, is as insufficient a comparison as the " chain" of older 

 writers.* 



Chapter VI. 

 NOMENCLATURE. 



The practice of using two names — generic and specific — for 

 each animal, or plant, originated with Linnaeus ; 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 opprobiura in all branches of 

 natui'al history. f 



* The quinary arrangement of the molluscous classes reminds us of the 

 eastern emblem of eternity — the serpent holding its tail in its mouth. 

 The foUowLiig diagram is offered as an improved circular system : — 

 [Fishes.] 

 Di-brauchiata. 

 Nucleo- Tetra- 



Opistho- i^^ Proso- 



Aporo- ^^J^ Polrao- 



Pallio- Lamelli- 



Hetero-branchiata. 

 [Zoophytes.] 

 t In Pfeiffer's 3Ionograph of the Helicidce, a family containing seventeen 

 genera, no less than 330 generic si/noni/ms are enumerated ; to this list, Dr. 

 Albers, of Berlin, has lately added another hundred of his own invention ! 



