152 DK. EMBLETON OX THE YENDACE. 



The skin of the Yendace and Trout is thick and tough, and 

 can easily be dissected off, whilst in the Herring it is thin and 

 delicate, and not easily detached from the muscles ; the skin of 

 the Yendace is silvery, and, like that of the Herring, devoid of 

 spots. 



The lateral line of pores exists very plainly in the Yendace 

 and Trout, very obscurely in the Herring ; the line of separation 

 between the dorsal and ventral muscles corresponding to the 

 lateral line is very conspicuous in the Yendace and Trout, when 

 the skin is removed, but is not perceptible in the Herring. 



The fins are not widely different in the three fishes, except that 

 in the Yendace and Trout, and not in the Herring, there is an 

 adipose or mucous fin between the dorsal and the root of the 

 caudal fin. The fin rays vary in different specimens of Yendace, 

 and are difficult to count. 



The inferior edge of the body in the Yendace, from the pec- 

 toral to the ventral fins, is like that of the Trout, being some- 

 what flattened, but beyond the ventrals is sharp or keel-shaped, 

 as the ventral line is all along the body in the Herring. 



The teeth of the Yendace are scarcely perceptible in the jaws, 

 and there are two or three rows of rudimentary teeth on each 

 side of the median line of the tongue. 



In the Herring, there are very minute and backwardly curved 

 teeth about the symphysis of the lower jaw, and rudimentary 

 teeth on the tongue and on the palate, as in the Yendace. The 

 angle formed at the back of the symphysis of the Herring is 

 bridged over for a small space by membrane, the posterior mar- 

 gin of which is crescentic, and there is a similar, though smaller, 

 arrangement behind the symphysis of the upper jaw. These 

 membranes exist also, though they are of less importance, in the 

 Yendace, but are absent in the Trout. At the upper part of the 

 symphysis of the lower jaw, but external to the mouth, is a 

 small smooth black knob in the Herring, but this is wanting both 

 in the Yendace and in the Trout. The Trout has numerous 

 conspicuous and sharp teeth in both jaws and on the tongue. 



Internal Organs. — The alimentary canal of the Yendace is 





