210 SIXTH REPORT — I83G. 



has few representatives in North America, their number not 

 exceeding one-thirtieth of the whole, while the European seas 

 nourish nearly one-fifth; the majority of the species, as in 

 most other acanthopterygian families, belong to the Indian and 

 South Seas. 



M(snoidecB. — Of this very small family, comprising only 42 

 species, about one half belong to the Indian and Polynesian 

 seas, one fourth frequent the seas of Europe, and only one 

 species, gerres aprion, has been detected on the shores of Caro- 

 lina, to which it ranges from between the tropics. 



Chcetodontoidccs . — This family, named also squammipennce , 

 contains about 150 species, of which the greater part are inha- 

 bitants of the Indian and Polynesian seas. One species only 

 {brama Rail) frequents the European coasts, while four are 

 North American, and one seventh of the whole exist on the 

 Atlantic coasts of North and South America. The pempheris 

 mexicanns is found at Acapulco ; the remaining species of that 

 genus inhabit the tropical, Pacific, and Indian oceans. 



The next family in Cuvier's arrangement is that of the ana- 

 hasidecB or polyacanthoidecE, containing only 40 species, all of 

 which belong to Southern Asia, except a spirohranchus, which 

 inhabits the rivers of the Cape of Good Hope. 



The preceding acanthopterygian families, with the addition of 

 the fistularoidece, hereafter mentioned, and the platessoidea:^ 

 anged by Cuvier with the malacopterygii, constitute Agassiz's 

 order Ctenoidei, so named from the pectinated laminae of their 

 scales. About 1400 recent ctenoideans have been described. 



Scomheroidece. — This family, included by Agassiz in his or- 

 der Cycloidei, is, next to the jiercoideoe, the most numerous 

 of Cuvier's acanthopterygii, the described species amounting 

 to more than 320. The scomber aiders, more than any other 

 group of fish of equal magnitude, affect the surface of the ocean 

 especially in the warm latitudes, and a considerable number of 

 the species i-oam from one side of the Atlantic to the other, 

 among which are the scomber grex, pelamys sarda, trichiurus 

 lepturus, elecate atlantica, lichia glauca, caranx carangus, 

 and nomeus Mauritii. Of sixteen genera, actually ascertained 

 to be North American, only seven enter the European fauna, 

 viz., scomber, pelamys, naucrates, caranx, seriola, temnodon, 

 and coryphcena ; but five of the remainder occur also on the 

 African shores of the Atlantic, viz., cyhium, trichiurus, elecate, 

 trachinntus, temnodon, and vomer, leaving only two of the 

 North American genera peculiar to the western side of the At- 

 lantic, viz., argyryosus and rhombus. The forms peculiar to 



