CLASS PISCES. 405 



bones do not appear, and in this group some have six 

 barbels *. 



The others have eight 2 . 



There are some with a naked and very broad head, 

 which are known under the name of cats {chats), and 

 their barbels, or cirrhi, are also sometimes six in num- 

 ber 3 : sometimes they are eight 4 . 



Some should be distinguished from the rest by a 

 small flat head, dorsals also extremely small, and 

 teeth nearly imperceptible 5 . 



Next come those pimelodi, which, besides the band 

 of teeth in the jaw, have plates of teeth to the pala- 

 tines. These palatine teeth may either be like the 

 pile of velvet, or the teeth of cards, and then the 

 buckler of the nape may be distinct from the helmet 6 : 

 or it may be united to it 7 . 



These palatine teeth are also sometimes round, like 

 small paving-stones 8 . 



There are some pimelodi very remarkable for the 

 pectiniform teeth, which form a moveable group 

 within the skin of the cheek 9 . 



1 Sil. 4-maculatus, Bl. 368. 2. Pirn, narndia, Cuv., Marcgr. 149. 

 Pirn, sebce, Cuv., Seb. III. xxix. 5. Pirn, pirinamp, Spix 8. 



2 Pirn, octo-cirrhus, Cuv., Seb. III. xxix. 1. 



3 New species. 



4 Sil. catus, Lin., Catesb. II. xxiii. 



5 New species. 



6 Pirn, herzbergii, Bl. 367 ? The Pirn. doigt-dc-Ncgre, Lacep. 



7 New species, i 



8 New species. 



9 Pirn, genidens, Cuv., new species. 



