1000 FISHES — GASTEROSTEID^. 



long and slender caadal peduncle, which is much depressed and strongly keeled, broader 

 than deep ; no dermal plates ; plates of the skeleton not all covered by skin ; post 

 pectoral plate well developed, striated ; head shortish, the snout rather blunt ; thoracic 

 processes well developed, widely divergent, forming a V-shaped figure ; dorsal spines 

 moderate, the anterior diverging to the right or left at different angles, the posterior 

 more nearly erect; anal spine large, larger than the dorsal spines; innominate bone 

 feeble, lanceolate, not carinated, its edges raised ; ventral spines moderate, serrulate, 

 length more than one-third that of head ; gill rakers long and slender ; giU membranes 

 posteriorly free from the isthmus ; head 4 ; depth 5^; D. IX-I, 9 ; A. I, 8. Length 2J 

 inches. 



Habitat, northern parts of Europe and North America, widely distributed, inhabiting 

 both salt and fresh waters. It is found in rather deep water in the Upper Great Lakes, 

 and northward to the Saskatchawan, and doubtless beyond. It has not yet been ob- 

 served in Lake Erie. 



I have compared numerous specimens of the lake form (var. nebulosus), 

 sent me by Dr. P. R. Hoy, from Racine, Wisconsin, with examples of the 

 common marine form of G. pungitius, and I find no constant difference 

 Dr. Bean finds also no difference between the marine form found in 

 America (occidentalis) and the common G. pv/ngitius of Europe. 



The habits of the lake form have necessarily become somewhat changed 

 from those of its marine relatives. 



Diagnosis. — This species may be known at once from all other little 

 fishes found in our fresh waters by the presence of about ten spines in 

 its dorsal fin, arranged in a zigzag row, and entirely disconnected from 

 each other. ' 



Habits. — Little distinctive is known of its habits. It has thus far been 

 found in rather deep water in Lakes Michigan and Superior, and, al- 

 though not generally common, it may sometimes be found in considerable 

 numbers. It is a most active and graceful little fish, and with it we 

 close our series of the Fishes of Ohio. 



