138 UMBRINA ALBURNUS. 



exposed ; it is armed in like manner, but wants the external row of larger teeth. 

 The tongue is large, smooth, thick, fleshy, round, and free in front. The vomer 

 and palate-bones are without teeth ; but the phai-yngeals are studded at intervals 

 with rather stout, conical, sharp-pointed, recurved teeth. At the chin is a short, 

 stout, conical barbel, truncated at its apex ; it is moved by a delicate muscle on 

 each side, which arises from the lower jaw, and is inserted by a minute tendon 

 into the base of the barbel, and is supplied by twigs of the fifth pair of nerves. 

 On each side of the barbel are two pores. 



The pre-opercle has its angle rounded, and is without denticulations ; the 

 opercle is rather broad, and terminates posteriorly in two flat points ; the whole 

 head, pre-opercle, and opercle are covered with scales, those on the latter bone 

 being largest. There are seven branchial rays, but the two upper are compressed 

 and concealed by the opercle, and the two inferior are so small that they can 

 only be well seen after dissection. 



The dorsal fin begins opposite the origin of the ventral, and terminates before 

 the root of the caudal ; its anterior portion has ten spines, of which the anterior 

 is so short as to be seen only on close examination, while the second, third, and 

 fourth are very long, the third most so of all ; the second portion of the dorsal 

 has one delicate spine and twenty-six soft rays. The pectoral fin is large, strong, 

 broad, and rounded posteriorly ; it arises in front of the dorsal, and terminates 

 opposite its soft portion, and has twenty rays, with an elongated triangular fold 

 of skin covered with scales in the axilla. The ventral fin is short, broad, thin ; 

 it begins about the anterior fourth of the pectoral, but does not extend as far 

 back, and has one spine and five soft rays, with a small, loose fold of skin in the 

 axUla above. The anal is small, and arises o^jposite the twelfth dorsal soft ray, 

 and has but one spine and eight soft rays, of which the third, fourth, and fifth 

 are longest. The caudal fin is short, sub-crescentic, the upper horn thinner and 

 smaller, though of equal length. 



The scales are sub-quadrilateral in form, a little longest in the antero-posterior 



