PRIMARY DIVISIONS. 7 



great families of Scomheridcs and ZeidcB, or the mackerel 

 and dories. These^ in contra-distinction to the last, have 

 the scales in general remarkably small — often, indeed, 

 almost invisible : the bones of the head and gills are of 

 the ordinary structm-e ; but the latter are rarely, if ever, 

 defended by spines : the body is smooth, but the back 

 is often armed with prickles, and the dorsal fins are 

 sometimes singularly developed. — 3. The Gymnetres, 

 represented by the genus Gymnetrus of Bloch, includes 

 also that of Cepola, and all those which have been aptly 

 denominated riband-fishes, from the excessive thinness 

 and disproportionate length of their bodies : like the last 

 tribe, the scales are very small, often imperceptible, and 

 the whole structure altogether peculiar. — 4. The Can- 

 TEiLEPTES, or mailed cheeks (called by Cuvier Buccce 

 Loricatcs), have the bones of the head greatly de- 

 veloped, and generally terminating in large spines : the 

 scales are small in the typical examples, and rough or 

 prickly : the pectoral fins highly developed, and the 

 gill opening much contracted. -^5th^ and lastly, come 

 the Blennides, or blennies, known at once by the 

 flexibihty of their dorsal rays, the slimy nature of 

 their bodies, the peculiar forms assumed by the ven- 

 tral fins, and, lastly_, the viviparous nature of their 

 generation. 



(6.) The affinities by which the foregoing tribes are 

 connected into one great circular group, will be enlarged 

 upon when we come to treat of each in detail. It is 

 easy for the ichthyologist to perceive that the two first 

 — the Macroleptes and the Microleptes — comprehend 

 the most highly organised fishes in existence, and that 

 they consequently become the typical tribes. The three 

 others, far less numerous in species, will therefore be 

 aberrant : they show, indeed, enough of the typical 

 characters of the order to make us include them therein ; 

 but in other respects they partake so much of the pecu- 

 liarities belonging to other tribes, that we plainly per- 

 ceive they only form connecting links between the pri- 



B 4 



