ABSTRACT 



A key is given to the North American genera {Asellus and Liroeus) of 

 asellid isopods. Another key is provided for the surface- living species 

 of Asellus but lack of clear, published morphological distinctions in 

 the genus Liroeus prevents the construction of a key for that genus. 

 Notes on ecology, collection, preservation and identification are also 

 included. 



