$. V. ARRANGEMENT. 18i) 



A Permanent species ( Species permaneiis s. genu- 

 ina) exhibits those parts of a plant or animal, which 

 have been selected according to the following prin- 

 ciples. 



1. The parts must be such as are characteristic 

 of the order or genus of the original. 



2. They must afford sufficiently discriminative 

 specific marks. 



3. Different parts must not be assumed as foun- 

 dations of permanent species in the same family or 

 subdivision of a genus. 



principle, on which the species of reliquia might be grounded, how- 

 ever obvious or simple that principle may seem. That the prin- 

 ciple in question has occasionally been used, we do not deny but 

 it never appears as a fixed and fundamental part, in any arrange- 

 ment of extraneous fossils we have yet consulted-^-L/#7zs takes 

 Ills species of these bodies sometimes from ihe genera of the re- 

 cent subjects (e. g. Helminthol. Anomitts HtLn. Madreporus, 

 &c.) and sometimes from the tribes or orders (e. g. Phyt. Filicis 

 Phyt. Plant ce, &c.) sometimes from the species (e.g. Helm. 

 Cranlolaris, &c.) and sometimes from the parts of the originals 

 (e. g. Phyt. Lithophyllum. Phyt. Uithoxylon, &c.) Gmehn 9 -'m 

 the last edition of the Syst. Naturte, is equally destitute of any 

 regular principle in the formation of his species ; and, though his 

 arrangement is built on the originals, has assumed, in two instances, 

 the substance of the matrix, as a specific distinction for the inclosed 

 reliquia! (Ichth. nigerlchth. pallidus. Syst. Nat. T. III. p. 385.) 

 It is almost needless to add, that Waller ius t Woltersdorf, Vogfl, 

 Cart hi user, &c. (who have made the originals the foundation of 

 their systems of reliquia) are also wanting in a regular and fixed 

 principle, for the construction of the species they enumerate. 



