FISHES OF MASSACHUSETTS. 83 



ing several striae, and, under the microscope, a great number of 

 very minute points or granulations, giving a rough feel to their 

 surface. The number of the scales in an oblique direction, 

 from the origin of the dorsal fin to the abdomen, is ten. The 

 lateral line, which is very distinct and nearly straight, passes 

 through the seventh row of scales. Length of the head, one 

 fifth the length of the body, flattened between the eyes : eyes 

 moderate in size ; pupils black ; irides silvery ; diameter of the 

 eye equal to half the distance between the eyes. Mouth small ; 

 jaws toothless ; upper jaw the longer. Nostrils large. Sub- 

 orbitar and opercular surfaces, golden ; the latter covered with 

 delicate striae. 



The Dorsal fin arises on the anterior half of the body, as 

 long again as high : the first two rays are spinous ; the first, 

 very short and slightly roughened behind ; the second, large 

 and strongly serrated behind. 



The Pectorals arise in front of the dorsal fin, at a distance 

 equal to half their length ; their length equal to one sixth their 

 height. 



The Yentrals are situated under the anterior portion of the 

 dorsal fin, at the posterior third of the pectorals ; their length 

 to their height as 2 to 7. 



The Anal fin is higher than long ; its first two rays are spi- 

 nous, serrated behind, resembling those of the dorsal. 



The Caudal fin is lunated, its depth at the base to its length 

 as 6 to 9. 



The fin rays are as follows : D. 15 ,- P. 15 ; Y. 9 ; A. 17 ; 

 C. 18. 



The appearances of this species in color, forms of its fins, and 

 many other particulars, vary exceedingly by domestication. 



Catostomus. Le Sueur. 



Generic characters. Back loith a single fin : gill mem- 

 branes three rayed ; head and opercula smooth ; jaws toothless 

 and retractile ; mouth beneath the snout ; lips plaited, lobed, or 

 carunculated, suitable for sucking. Throat with pectinated 

 teeth. 



