42 NORTHERN ZOOLOGY. 



as broad as it is long: its height is two-thirds of its breadth. The jaws are equal. There 

 are no conspicuous spines on the head, but the preoperculum ends posteriorly in a little point 

 that is bent upwards, and is concealed in the thickness of the skin. The operculum terminates 

 in a rounded process, whose membraneous edging has two acute angles. There are six slender 

 cylindrical rays in the branchiostegous membrane : in gobio the rays are stronger and flatter. 

 The membranes can be inflated : the isthmus, or space between their insertions, measures half 

 an inch. Body moderately compressed, and tapering gradually from the broader head to the 

 caudal fin : its greatest height, which is at the beginning of the dorsal, is nearly the same with 

 its transverse diameter there, but the compression is more decided towards the tail, whose 

 thickness at the insertion of the caudal is little more than half its depth. The belly and 

 under surface of the head are flattish, the back is more acute, particularly the posterior part of 

 it. The anus, situated precisely as in gobio, is rather nearer to the snout than to the insertion 

 of the caudal. There are no scales, the body and head being covered with soft skin. The 

 lateral line consists of a series of little depressions with raised margins, and runs parallel to 

 the ridge of the back, and nearer to it than to the belly. 



Teeth. — The intermaxillaries, lower jaw, and vomer, are armed with short teeth, en velours. 

 The tongue is smooth, very broad, short, and fixed. 



Fins.— Br. 6 ; P. 15; V. 1/4 ; D. 8/ — 18 ; A. 14 ; C. 15. 



The pectoral fins are large and fan-shaped, their longest rays, as in gobio, equalling the 

 head in length. They are all articulated and unbranched. The ventrals, arising a little 

 behind the pectorals, contain five rays ; the first of which, a slender spine half the length of 

 the others, is so closely applied to the succeeding articulated one as scarcely to appear dis- 

 tinct until the integuments are removed. Cuvier describes gobio as having one spinous ray in 

 each ventral, and only three articulated ones ; but in Mr. Yarrell's English specimen these 

 fins correspond exactly, in the number of their rays, with cognatus. 



The first dorsal commences a little farther back than the ventrals, and exactly at the same 

 distance from the snout as in gobio, but it extends about a line farther along the back, and 

 contains two more rays than in that species. All the rays are very slender and flexible, but 

 not articulated, and are connected to their tips by a delicate membrane. The longest mea- 

 sures one- third of the height of the body. The second dorsal arises within less than a line of 

 the first, and has an attachment twice as long, reaching to within three lines of the insertion 

 of the caudal. Its rays (eighteen) are articulated and simple, except the two central ones, 

 which are very slightly forked. [The English specimen of gobio has only six rays in the first 

 dorsal, but Cuvier says they vary from six to nine : and the second dorsal has sixteen rays all 

 articulated and simple, though Cuvier describes the last ray as forked, and some of the others 

 as branched. There is a space, measuring two and a half lines, between the first and second 

 dorsals, and their rays are one-third shorter than the corresponding ones of cognatus.] 



The anal fin, similar in form to the second dorsal, has fourteen rays all articulated and 

 simple. It commences opposite to the sixth ray of the second dorsal, and does not reach 

 quite so near to the caudal fin. The caudal unites with the tail in a straight line, and con- 

 tains fifteen rays, all more or less forked. It forms one-sixth of the total length as in gobio. 



