56 CALIFORNIA ACADEMY OF SCIENCES. 



example, Ventura, March: holmbergi, Santa Monica and 

 San Diego, not very common: lineatus, abundant at 

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

 records Icevipennis from Fort Tejon, and I have taken 

 cribricollis at San Francisco and Lake Tahoe. 



Hydrsena. H. pennsylvanica, common everywhere in 

 same situations as Ochthebius. 



Hydrophilus. H. triangularis, 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. punctatissimus, not rare, Pomona to San 

 Diego: miles, plentiful at Yuma: subsiynatus, Colorado 

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

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

 gust: infuscatus, 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. 



