14 Proceedings of the Biological Society of Washington. 



The last two species and the shad exemplify gradations of a funda- 

 mentally simple habit. All are anadromous, and ascend the river 

 primarily to spawn. The shad do not linger after performing this function 

 and the young apparently soon leave the upper river. Adults of the 

 striped bass behave about the same while young of various sizes linger in 

 these waters. The adults of white perch, however, are apparently at 

 home in our waters, and some of them are present throughout the year. 



Summary. 



Of the 54 species in the above list 10 are known to have been introduced 

 into the Potomac and possibly some of the others were. The known in- 

 troductions include two species of catfish, the carp, two crappies, the 

 goggle-eye, the warmouth, one sunfish, and two kinds of bass. 



Approximately 83 per cent of the species belong to five families of 

 fishes, while the remainder, 9 species in all, represent 8 families. The 

 Cyprinidfe or minnow family ranks first with 19 species; the other 

 important families are sunfishes and bass (Centrarchidse), 10 species; cat- 

 fishes (Siluridse), 6 species; and suckers (Catostomidse), and perches 

 (Percidse) with 5 each. 



Bibliography. 



Smith, Hugh M., and Bean, Barton A. 

 List of fishes known to inhabit the waters of the District of Columbia 

 and vicinity. Bull. U. S. Fish Commission. (1898), 1899, pp. 179- 

 187. Records 8 species from our region. 

 Bean, Barton A., and Weed, Alfred C. 

 Recent additions to the fish fauna of the District of Columbia. Proc. 

 Biol. Soc. Wash. 24, pp. 171-174, June 16, 1911. Records 4 species 

 from Cabin John Run. 



