GILLS OF FISHES. 



481 



LepadoriaHtcr, and tlie Ci/flopterus liparis have tlircc biscrial gills 

 anil one nniscrial gill; the genera Lopliivs, Bafr/icli/is, DioiJon, 

 Tetrodon, Monopfcriis, Coti/lis, have three hiserial gills ; Maltlicea 

 and Lepidosiren have two biserial gills and one uniserial gill ; the 



319 



320 



Section ct brnnr-liial arch with a pair of processes 

 A', supporting the branchial plates, b, Cod. 

 ccLxyiii. 



Section of branchial arch, a, with snpportint,' frame- 

 work of Uie iilate-bearing jirocesses. Cod. 



CCLXYIII. 



Ciicliia (AmpJiipmous) has only two gills. The above ennmeration 

 refers to the branchial organs of one side ; they are symmetrical 

 in all fishes, and the uniserial ojiercular gill is not counted, as not 

 being attached to a proi)er branchial arch. 



The Ijranchial processes are bony, at least along the outer and 

 thicker border, in most Osseous Fishes (e.g. Salmo, Alosa, Gadus). 

 They are gristly, like the arches which support them, in the 

 Sturgeon, where they break up into delicate branched fringes, 

 along their outer margin. Small ' interbranohial ' muscles extend, 

 through the uniting septum, between the bases of the processes, 

 for effecting slight reciprocal movements.' 



' CXII. CXIII. 



VOL. r. I I 



