Shore flies of the genera Coenia Robineau-Desvoidy and Paracoenia Cresson are revised, resulting in the description of two new subgenera of Paracoenia, Calocoenia and Leptocoenia, and of four new species, Paracoenia ampla, P. calida, and P. wirthi from California, and Coenia alpina from Labrador, Canada. Biological information on P. turbida and P. calida is given and the known distribution for each species is presented. P. paurosoma is reported from the Palearctic Region for the first time based on specimens from Sweden; several new distribution records from North America are also included. Characters of the male postabdomen are used, and the male genitalia of each species are illustrated. Keys or references to all known species of these genera are included.
Mathis, Wayne N.
"A systematic study of Coenia and Paracoenia (Diptera: Ephydridae),"
Great Basin Naturalist: Vol. 35
, Article 8.
Available at: http://scholarsarchive.byu.edu/gbn/vol35/iss1/8