THE HADDOCK. 55? 
Their free margin is even, a characteristic to which 
the term cycloid is applied, in contrast to ctenoid, which 
n.@., Nasal apertures (double on each side); @. 7.1, df.2, 2,/.3, dorsal 
unpaired fins ; c.f, the caudal fin of the homocercal tail. 
&., Barbule; 9f., operculum covering the four gills; 47.7., con- 
tinuation of the gill-cover forming the branchiostegal mem- 
brane ; Av. /, pelvic fin(=hind-limb)—note its jugular position 
in front of J.f£, the pectoral fin (=fore-limb). 
a., Anus; g, genital aperture; #., urinary aperture; @./.1, @,/.2, 
unpaired anal fins. : 
describes those scales which have a notched or comb-like 
Fic. 293.—External characters of a Teleostéan— 
a carp (Cyprinus carpio).—After Leunis. 
R., Dorsal unpaired fin; S., homocercal caudal fin; A., anal fin; ~ 
B., B., pectoral and pelvic paired fins. Note also the lateral 
line and barbule. 
free margin. Over the scales extends a delicate partially 
pigmented epidermis. 
Appendages.—The pectoral fins are attached to the 
