HYDROPHILIDAE
Helophorinae
Helophorus linearis LeConte  (15)
H. sp.  (1)
Epimetopinae
Epimetopus sp.  (8,18)
Hydrochinae
Hydrochus simplex LeConte  (18)
H. undulatus Hellman  (2)
Hydrophilinae
Berosini
Berosus aculeatus LeConte  (1)
B. exiguus (Say)  (1,8,18)
B. infuscatus LeConte  (1,8,18)
B. miles LeConte  (8,18)
B. pantherinus LeConte  (1,8,18)
B. peregrinus (Herbst)  (1,8,18)
B. pugnax LeConte  (1)
B. striatus (Say)  (1,11)
B. stylifer Horn  (8,18)
Chaetarthriini
Chaetarthria atroides Miller  (10)
C. bicolor Sharp  (8,18)
C. hesperia Miller  (10)
C. pallida (LeConte)  (10)
Anacaenini
Paracymus communis Wooldridge  (16)
P. confusus Wooldridge  (8,17,18)
P. subcupreus (Say)  (1)
Crenitis digestus (LeConte)  (9, as Paracymus)
Anacaena limbata (Fab.)  (1)
Laccobiini
Laccobius agilis (Randall)  (1)
L. minutoides Orchymont  (8,18)
L. teneralis Cheary  (8,16,18)
Hydrophilini
Helochares maculicollis Mulsant  (1,8,18)
Enochrus blatchleyi (Fall)  (1)
E. cinctus (Say)  (1,8,18)
E. diffusus (LeConte)  (1)
E. hamiltoni (Horn)  (1,5,8,18)
E. ochraceus (Melsheimer)  (1,8,18)
E. perplexus (LeConte)  (1)
E. pygmaeus nebulosus (Say)  (5,8)(9,18, as pygmaeus Fab.)
E. sayi Gundersen  (5,8,18)
Cymbiodyta beckeri Smetana  (8,12,18)
C. dorsalis (Motschulsky)  (12)
C. toddi Spangler  (5,12,16)
Helocombus bifidus (LeConte)  (1)
Hydrobius fuscipes (L.)  (1)
H. melaenum (Germar)  (1)
H. tumidus LeConte  (1)
Hydrochara leechi Smetana  (8,14,18)
H. obtusatus (Say)  (1, id prob. Incorrect)
H. occulta (d'Orchymont)  (8,14,18)
H. soror Smetana  (8,14,16,18)
H. spangleri Smetana  (8,14,18)
Tropisternus blatchleyi Orchymont  (8,18)
T. collaris (Fab.)  (8,18)
T. ellipticus (LeConte)  (8,9,11,18)
T. lateralis (Fab.)  (1,6,7)
T. lateralis nimbatus (Say)  (8,18)
T. mexicanus mexicanus Laporte  (1,6)
T. mexicanus striolatus (LeConte)  (1)
T. mixtus (LeConte)  (1)
T. natator d'Orchymont  (1,8,18)
T. sublaevis (LeConte)  (1)
Hydrophilus ovatus (Gemminger & Harold)  (8,18, as Dibolocelus)
H. triangularis Say  (1,8,18)(7, as Hydrous)
Sphaeridiinae
Coelostomatini
Dactylosternum sp.  (11)
Phaenonotom exstriatum (Say)  (13)
Megasternini
Cercyon analis (Paykull)  (13)
C. connivens Fall  (13,16)
C. haemorrhoidalis (Fab.)  (1,4)
C. h. herceus Smetana  (13)
C. lateralis (Marsham)  (4)
C. mendax Smetana  (13)
C. praetextatus (Say)  (4,13)
C. pygmaeus (Illiger)  (4,13)
C. quisquilius (L.)  (4,13)
Sphaeridiini
Sphaeridium lunatum Fab.  (4,13)
S. scarabaeoides (L.)  (3,4)
 1.  In OSU Collection - Det. C. A. Frost
 2.  In OSU Collection - Det. J. L. Hellman
 3.  In OSU Collection - Det. J. H. Robinson
 4.  Reported by Blume, 1985
 5.  Reported by Gundersen, 1977
 6.  Reported by Hatch, 1930
 7.  Reported by Hatch & Ortenburger, 1930
 8.  Reported by Kondratieff et al., 2005
 9.  Reported by McKinley et al., 1972
10. Reported by Miller, 1974
11. Reported by Reisen, 1975
12. Reported by Smetana, 1974
13. Reported by Smetana, 1978
14. Reported by Smetana, 1980
15. Reported by Smetana, 1985
16. Reported by Smetana, 1988
17. Reported by Wooldridge, 1966
18. Reported by Zuellig et al., 2006
21 genera - 70 species & subspecies