HISTORY OF THE FISHES OF MASSACHUSETTS. 77 



three spines are situated upon the preoperculum ; that at the posterior angle is the 

 largest of any upon the head ; it is very stout, is naked throughout its greatest extent, 

 and is partially covered by a loose membrane as a mere sheath, which is readily recurved 

 to its very base ; this spine extends backwards nearly to, and in some specimens as far 

 as, and I have seen it continued even beyond, the posterior extremity of the opercular 

 spine. Directly under the base of this spine is situated a second very small one, pointing 

 obliquely backwards and downwards ; at the inferior angle of the preopercle is a third 

 spine, pointing downwards and forwards. Two spines are seen upon the operculum ; 

 the larger passes from its upper anterior portion to the posterior angle, pointing obliquely 

 backwards; the other, which is quite small, is at the inferior angle, and points directly 

 downwards. Just above the origin of the pectorals is a strong scapular spine, directed 

 upwards and backwards. And above the commencement of the posterior fleshy mem- 

 brane of the operculum is seen the humeral spine, which is but little longer than the 

 occipital spines. 



The head is flattened above and furrowed by ridges which are the continuations 

 of the spines ; a slight ridge passes from the nasal spines backwards to the eyes ; 

 another extends from the post-orbitar to the occipital spines, and exterior to this is 

 another ridge ; the whole upper portion of the head is dotted with minute granulations. 

 The gape of the mouth is large ; the jaws, pharynx, and palatine-bones are armed with 

 numerous sharp, compact teeth, like those of a card ; the upper jaw is the larger. The 

 eyes are very large and prominent. The nostrils are small ; the posterior is just back 

 of the nasal spine ; the anterior is tubular, and on a line with the base of the nasal 

 spine exterior to it. The lateral line is very prominent, resembling an interrupted series 

 of tubercles. It commences at the scapular spine, and is continued to the caudal rays, 

 being much less marked at its posterior extremity. 



The first dorsal fin, which is composed of nine spinous rays, is longer than high. 

 The third ray is the longest ; the first ray is about half the height of the second ; the 

 extremities of the first six rays project beyond the connecting membrane. Dr. Dekay, 

 in speaking of this fin, says, " the second ray longest." He omits mentioning the first 

 very short ray ; and it does not appear in his figure. 



The second dorsal arises just back of the first, at the termination of a membrane 

 extending from the first dorsal. It is nearly as long again as the first dorsal ; its rays 

 are articulated. 



The pectorals are large and rounded. 



The ventrals arise beneath the lower rays of the pectorals ; simple. Rays free at 

 extremities ; first ray quite strong. 



The anal commences back of the second dorsal, and is shorter than that fin. 



