17: 



GANOID FISHES OF THE CARBONIFEROUS FORMATION 



The generic name is taken from Canobie, the district in which the fish-bearing beds 

 of Glencartholm are situated. 



1. Canobius Ramsati, Traquair. Plate XXXIX, figs. 1 — 3. 



Specific Characters. — Suspensorium nearly vertical, preoperculuin simulating that 

 of Eurynotus in being pointed above and below; body-scales comparatively smooth, 

 being marked only with faint ridges and furrows, posterior margins of the scales rarely 

 showing any denticles ; a row of especially large median scales runs along the back from 

 the occiput to the dorsal fin. 



Description. — Length 2^ to 3 inches ; shape shortly fusiform, deep in front and 

 tapering rapidly towards the tail. The length of the head is contained five times, and the 

 greatest depth of the body little more than three times in the total. 



The head is short and deep, with a very obtusely rounded snout in front, behind 

 which and nearly right over the mouth is a circular orbit of considerable size. As far 



Fig. 11. — Outline-sketch of the principal external head-plates in Canobius Ramsayi, Traq. br., brancluostegal 



rajs; d., dentary ; other letters as in Fig. 12. 



as can be made out, the bones of the cranial roof seem quite Palaeoniscoid in their 

 arrangement; their external surfaces are marked with comparatively coarse flattened 

 corrugations. The suspensorium is nearly vertical, being only very slightly inclined 

 backwards; the posterior margin of the opercular flap has a regularly curved semilunar 

 contour. The operculum is small, its anterior margin is nearly vertical, but its inferior 

 one is so oblique as to look as much backwards as downwards, and consequently the 

 posterior margin is considerably shorter than the anterior one, the superior being 

 the shortest of all. It is succeeded below by a suboperculum of a somewhat rhomboidal 

 shape, the acute angles being the postero-superior and the anteroinferior; its vertical 

 depth is fully as great as that of the operculum, and its anterior and posterior margins 

 continue uninterruptedly into the gentle curvature of those of that plate. The 

 preoperculuin simulates that of Eurynotus and other Platysomidae, being a narrow plate, 

 with acute superior and inferior angles and a very obtuse anterior one; its long posterior 

 margin, which fits on to the anterior margins of the operculum and suboperculum, is 

 gently convex and nearly vertical in position ; the other two short margins are gently 

 concave, the antero-superior being the longer, and fitting on to the posterior margin 

 of an elongated suborbital, while the shorter antero-inferior one is in contact with the 



