ORDER III. 



PHARYNGOGNATHI. 



The inferior pharyngeal bones unite together into an odd bony piece, oftentimes so inti- 

 mately as to leave no vestige of the original suture (for, homologically speaking, there are two 

 inferior pharyngeals, a right and a left); at others, though strongly united, a faint trace of the 

 suture is still apparent, as is the case in Ohromididae, of the acanthopterygian sub-order, 

 treated further on, and of which no representative has as yet been found in western North 

 America properly so called. The chromids belong to a more southern clime ; the valley of the 

 Rio Grande del Norte (Rio Bravo) appears to be its northern limit in this continent. 



Stn. — Pharyngognathi, Mull, in Wiegm. Arcliiv fiir Naturg. I, 1843, 305 ; &, I, 1845, 136. 



This order is composed of malacopterygians and acanthopterygians, the former having their 

 body protected with cycloid scales, whilst in the latter we observe both types : the cycloid and 

 the ctenoid according to the families. The air bladder, in the adult fish, has no air duct leading 

 to the mouth. The vomer and palatine bones are toothless. 



SUB-ORDER I. 



MALACOPTERYGII. 



The rays which enter into the composition of the fins are all of the soft and articulated kind, 

 some of which remaining simple whilst the others bifurcate to various degrees. The veatrals 

 are abdominal ; the dorsal is situated far back opposite the anal. The scales exhibiting the 

 cycloid structure. 



Stn. — Pharyngognathi malacopterygii, Mull, in Wiegm. Arch, fur Natur. I, 1843, 310 ; &, I, 1845, 136. 



Malacopterygii, Linn. SyBt. Nat. ed. VI, 1748.— Owen, Lect. comp. anat. Vert. 1846, 48.— Bd. Icon. Enc. II, 1850,204. 



A single family constitute, for the present at least, this sub-order. It was placed by former 

 systematic writers in the same order with the other malacopterygians (Physostomi) prior to the 

 anatomical researches of Professor Mtiller, who has brought to light the peculiar structure of 

 their inferior pharygeal bones as well as that of the air bladder, above alluded to. 



Family SCOMBERESOCIDAE, Owen. 



In this family we observe the same intimate union of the inferior pharyngeals without any 

 vestige of suture, as in Ldbridae and Pomacentridae. The body is elongated, sometimes very 

 considerably so, covered with scales, cycloid in structure, with a row of keeled ones on either side 

 of the belly and distinct from the lateral line. The dorsal fin is opposite the anal and composed 



