52 PEELIMINAEY EEPOET 



Genus PTGOSTEUS Brevoort. 

 Pygosteus pungitius (Linnsens). Nine-spined Stickleback. 



Olive above, much dotted; sides barred with dark; belly silvery. 

 Body slender, a little compressed, the portion before the caudal fin 

 very small. Head short and blunt; eye wider than the length of 

 the snout. Dorsal spines not all pointing in the same direction; 

 anal spine larger than the dorsal; gill rakers long and slender. 

 Head contained 4 times in the length. Depth 5 to 6. Dorsal rays 

 VIII or IX-1, 9. Anal I, 8. Length 3 inches. 



Not common in the state, so far as known. It was described 

 from Lake Superior as Gasterosteus nebulosus Agassiz, Lake Supe- 

 rior, 310, pi. 4, flg. 4, 1850. A specimen in the University museum 

 was taken in Lake Superior at Grand Marias by T. S. Roberts in 

 1879. 



Order ACANTHOPTERI. 



Family PERCOPSIDJl. The Trout Perches. 



Body elongate, rather heavy anteriorly, compressed posteriorly. 

 Head rather pointed; mouth small; eye large; maxillary bones 

 small; premaxillaries forming the upper jaw; upper jaw protrac- 

 tile; the jaws set with weak teeth. Gill membranes free from the 

 isthmus; pseudobranchia developed; branchiostegal rays 6; gill 

 rakers tubercle-like. The bones of the head cavernous ; scales cten- 

 oid, lateral line present. Several well developed pyloric caeca. 



Genus PERCOPSIS Agassiz. 



Percopsis guttatns (Agassiz). Trout Perch. 



Body somewhat mottled with light and dark colors, upper parts 

 with many dark spots. Body rather heavy, quite small just before 

 the caudal fin ; head conical, not covered with scales ; mouth small. 

 Head contained 3 4-5 times in the length. Depth 4^. Dorsal fin 

 inserted about the middle of the body, its rays II, 9. Anal I, 7. 

 Ventrals each I, 8. About 50 scales in the lateral line. Length 

 6 inches. 



This little fish is everywhere common in the northern part of the 

 state. A large number of specimens have been collected in the 

 streams and lakes of the Upper Mississippi (Nat. Hist. Surv., 

 1892-3-5) ; more than 500 specimens were taken at one haul with a 

 small seine in the St. Louis River at the mouth of the Cloquet River 

 (Woolman & Cox, 1894). 



