Stenetmis mavkeli- Motschulsky, 1854. In streams from Massachusetts 



south to Tennessee and west to Wisconsin and Oklahoma. 

 Stenetmis mera Sanderson, 1938. In streams from Quebec south to North 



Carolina and west to Wisconsin and Arkansas. 

 Stenetmis mirabitis Sanderson, 1938. In eastern streams from 



Connecticut to South Carolina. 

 Stenetmis musgravei Sanderson, 1938. In streams from New York to 



South Carolina and west to Wisconsin and Texas. 

 Stenetmis parva Sanderson, 1938. In streams in southeastern Oklahoma 



and eastern Texas. 

 Stenetmis quadrdmacutata Horn, 1870. In lakes and marl bogs from 



Quebec to Maryland and west to Indiana and Michigan. 

 Stenetmis sandersoni Musgrave, 1940. In streams from Ontario and 



West Virginia to northeastern Oklahoma. 

 Stenetmis sextineata Sanderson, 1938. In streams from Tennessee and 



Kentucky to Indiana, Kansas, Oklahoma, and Texas. Tolerant of 



moderate pollution by sewage, phosphate, and a variety of wastes. 

 Stenetmis sinuata LeConte, 1852. In sandy streams from Florida to South 



Carolina and west to Mississippi. 

 Stenetmis vittipennis Zimmerman, 1869. In streams from Quebec to South 



Carolina and west to North Dakota and Kansas. 



Genus Zaitzevia Champion, 1923 



Zaitzevia parvuta (Horn, 1870) . Usually in gravel or under rocks in 

 fast mountain streams of western states from New Mexico to 

 California and north to South Dakota, Montana, and British Columbia. 



Zaitzevia thermae (Hatch, 1938) . In warm springs of Montana. (Perhaps 

 this is only an ecological variant of Zaitzevia parvuta.) 



Family DRYOPIDAE (Erichson, 1847) 



Genus Dry ops Olivier, 1791 



Dryops arizonensis Schaeffer, 1905. Usually just above the water line 

 in debris caught on sticks or rocks in stream riffles (or taken at 

 lights) in central and southern Arizona. 



In addition to this known distribution of Dryops in the United States, 

 we may expect the genus to occur in southeastern California, in New 

 Mexico, and in Texas along the Rio Grande (I have taken it just over the 

 border in Mexico) . Furthermore Dryops viennensis (Heer, 1841) , an acci- 

 dentally imported species from Europe, has become established in Quebec, 

 and is to be expected in Maine. 



Genus Hetiohus Erichson, 1847 



Eetiohus basatis LeConte, 1852. Beneath rocks near the shore in streams 

 from Georgia to Massachusetts and west to Texas, Kansas, and Ohio. 



21 



