CRENILABRUS. 263 



er varieties we have not succeeded in procuring 

 them. The fins are somewhat brownish, and dark 

 spots are indistinctly seen on the sides. 



GEN. CRENILABRUS. 



Blue-Back, — Crenilabrus Merula. This ap- 

 pears to be the perca varia of Dr Mitchell, 

 which is an abundant and savory article at New 

 York, and usually caught at Sandy Hook. It is 

 only occasionally found in Massachusetts, under 

 the name of the blue-back, in reference, probably, 

 to its color. The length varies from ten inches 

 to sixteen, having large scales, and u ndivided cau- 

 dal fin. In the branchial membrane are eight 

 rays ; pectoral fin eighteen, ventral six, dorsal 

 twenty one, anal eleven, and caudal seventeen rays. 



A fish very similar, crenilabrus lapina, of the 

 Mediterranean, is spotted in three rows, on the 

 side, and at Sandy Hook, it is speckled with black 

 and white, from the head to the tail. A differ- 

 ence in the quality of the water, in this instance, 

 certainly gives the New Yorkers the advantage 

 over us, in possessing an excellent fish, which, 

 when it wanders into this vicinity, is not only 

 changed in color, but rendered impotent and bar- 

 ren. 



