628 TAXONOMY 



is more appropriately called in Fabricius Scarabeeus, than in Latreille 

 Geotrupes, for, next to the cockchafer, it is the commonest of all Lin- 

 naeus' Scurabei. 



357. 



Family groups were deficient in the older systems, and therefore also 

 family names ; but as the families have been chiefly formed from the 

 external resemblance of their individuals, it appears appropriate to 

 express this conformity in the name, and they are therefore called 

 after the best known genus. Thus Jussieu proceeded when he 

 devised names for his natural families of plants. They took the form 

 of an adjective, as the substantive planta was tacitly understood ; all 

 therefore required the feminine gender, for example, Malvaceae, Gra- 

 minece, &c. 



Latreille, the first founder of families among insects, selected also 

 generally the adjective form, but he did not consider that the word 

 insectum was to be understood, and that, consequently, they should be 

 neuter. The gender of these names appeared to him indifferent, and 

 we thence find in the same order every possible form, for example, 

 Cicindelette, Carabici, Malacodermi, Pimeliarice, Melosomce, Bru- 

 chela;, Rhyncosloma, &c. But all adjectives must necessarily, even 

 when they stand alone, refer to an understood substantive, which in 

 this case can be no other than inseclum or insect a, and therefore all 

 generic names must, according to the first grammatical rule that the 

 predicate shall agree with its subject in gender, number, and case, be 

 in the neuter. Latreille's family names must therefore be corrected by 

 this and the previously instituted laws. Let us examine more closely 

 the way in which he and others have constructed the names of families. 



358. 



Four different paths have been followed in the structure of family 

 names. 



The first is that pursued by Jussieu in botany, namely, to form an 

 adjective name from the chief genus of a family for its distinction, and 

 by means of this name to indicate its resemblance with a known form. 

 This process appears to be the best, in the first place, because we can 

 never be at a loss for a family name, and secondly, because these adjec- 

 tives are easily formed, and merely the knowledge of the derivation of 



