HISTORY OF THE FISHES OF MASSACHUSETTS. 275 



their entire surface, including oftentimes the fins. Irregular bluish lines, appearing 

 like hieroglyphics, are distributed over the head ; these are more strongly marked 

 between and in front of the eyes than on the neck. The pupils are black, the irides a 

 beautiful silver. 



Bescription. Form elongated. Its height measured across to the anus, including 

 the dorsal fin, is not quite equal to one third of its length ; its thickness is about equal 

 to half of its height, not measuring the dorsal fin. The length of the head to the 

 length of the entire fish is as one to four : it is slightly flattened upon its top, and on 

 the back of the neck, in front of the dorsal fin, is a perceptible convexity. The portion 



he head between the eyes, and in front of them to the angle of the jaws, is 

 destitute of scales, as well as the lower portion of the opercula. The scales upon 

 the operculum are larger than those upon the preoperculuni. The preoperculum is 

 finely denticulated upon its posterior edge, throughout its whole length : the 

 posterior edge of the operculum is bordered by a fleshy membrane. 



The jaws are equal, and are armed with numerous teeth ; the six front teeth in 

 either jaw larger than the others ; the front teeth in the upper jaw larger than the 

 corresponding ones in the lower. The upper jaw is very projectile. The lips are 

 large and fleshy. The eyes are circular ; the diameter of the eye is equal to one 

 fifth the length of the head. 



The lateral line arises just back of the superior angle of the operculum, and curves 

 with the body until about opposite the termination of the dorsal fin, whence it 

 pursues a straight course to the tail. - 



The dorsal fin arises on a line with the posterior angle of the operculum, and 

 terminates within about an inch of the tail It has eighteen strong spinous rays, the 

 extremities of which are naked ; the upper portion of their connecting membrane is 

 free, presenting the appearances of small filaments or tentacles ; the eleven posterior 

 rays are membranous. The spinous rays gradually increase in height from the first to 

 the membranous rays, which are still more elevated. The first spinous ray is very 

 short, being only one seventh the height of the last spinous ray. The membranous 

 portion of this fin is rounded when expanded. 



The pectorals arise on a line with the dorsal; their height is to their length as 



three to one. 



The ventrals are just back of the pectorals ; the first ray is a strong spine- The 

 length of these fins is to their height as one to three. 



The anal fin has three spinous rays ; from the extremities of these spines, as well as 

 from that of the ventral fins, filaments are suspended as in the dorsal fin. 



