56 CALIFORNIA ACADEMY OF SCIENCES. 



example, Ventura, March: hotmbergi, Santa Monica and 

 San Diego, not very common: lineatus, abundant at 

 Yuma, July: nitidus, Yuma (Le Conte). Dr. Horn 

 records laivipeniiis from Fort Tejon, and 1 have taken 

 cribricollis at San Francisco and Lake Tahoe. 



Hydraena. — H. pennsylvanica, common everywhere in 

 same situations as Ochthebius. 



Hydrophilus. — H. trio/ngularw, not rare, comes quite 

 often to electric lights: insularis, said by Horn ("The 

 Coleoptera of Baja California ")'^ to occur in Southern 

 California. 



Tropisternus. — All the species common and generally 

 distributed except salsame.ntus, which has occurred only 

 in the Redondo salt lake, April to June, and in salt pools 

 at Santa Barbara, August. 



Hydrocharis. — H. glaucus, three examples taken by 

 Mr. F. D. Twogood in a watering trough at a lumber 

 camp in the San Bernardino Mountains, elevation 5,000 

 feet, September; found also on Santa Cruz and Santa 

 Rosa islands, but everywhere rare; and by Dr. Blaisdell 

 in Calaveras Mountains, Mokelumne Hill and on Mt. 

 Diablo (Fuchs): obtusatus, one example in mountains 

 near Pomona, elevation 4,000 feet, August: rickseckeri 

 occurs near Santa Rosa (Ricksecker), 



Berosus. — B. pundatissinius, not rare, Pomona to San 

 Diego: mUe.s, plentiful at Yuma: subsignatus, Colorado 

 River: salinus, Redondo salt lake, not rare in early 

 spring; found also in salt pools at Santa Barbara in Au- 

 gust: infu!<catus, Yuma, San Diego, Redondo, Pomona, 

 etc., rather common: rugulosus, very rare, only two 

 examples found, Pomona, June and September. 



Chaetarthria. — All three species are found about equally 

 common by washing the sandy margins of streams. 



*Proc. Cal. Acad. Sci., 2nd Ser., Vol. IV, 18H p. 315. 



