HISTOKY. 23 



Under tlie name of PharyngognatM he combined fishes 

 with the lower pharyngeals coalesced into one bone, \dz. the 

 Labroids, Chromides, and Scombresoces. The association of 

 the third family with the two former seemed to himself a 

 somewhat arbitrary proceeding ; and it had to be abandoned 

 again, when a number of fishes which cannot be separated 

 from the Acanthopterygians, were foimd to possess the same 

 united pharyngeals. 



A more natural combination is the union of the Cod-fishes 

 with the Flat-fishes into the order Anacanthini. Flat-fishes 

 are in fact nothing but asymmetrical Cod-fishes. Miiller 

 separates them from the remaining Malacopterygians by the 

 absence of a connecting duct between the air-bladder and 

 oesophagus. However, it must be admitted that the examina- 

 tion of those fishes, and especially of the young stages, is not 

 complete enough to raise the question beyond every doubt, 

 whether the presence or absence of that duct is an absolutely 

 distinctive character between Anacanths and Malacoptery- 

 gians. 



Many of the families established by Cuvier were re- 

 examined and better defined by Miiller, as may be seen from 

 the following outline of his system : — 



Sub-classis I. — Dipnoi. 

 Ordo I. — SirenoideL 

 Fam. 1. Sirenoidei. 



Sub-classis II. — Teleostei. 



Ordo I. — ^Acanthopteri. 



Fam. 



