346 



Leech and Chandler: Coleoptera 



1.75-2.5 mm. long, occurring near margins of fresh 

 water; California to Washington 



kulzeri Knisch 1922 



2. Elytral striae deeply impressed from base to apex 

 only lateral ones visibly punctate; mesosternal pro 

 tuberance narrowly fusiform, 3 times as long as wide 

 acute anteriorly, rounded posteriorly, slightly convex 

 punctate; color variable: pronotum and elytra yellow 

 to almost entirely black; Alaska to Baja California 



fimbriates Mannerheim 1852 



— Striae lightly impressed and finely punctate on disc, 

 evanescent laterally; mesosternal protuberance a nar- 

 row, finely punctate carina; color variable, usually with 

 elytra testaceous, pronotum rufotestaceous with median 

 black mark; Alaska to Baja California; Carmel, Mon- 

 terey County; Palo Verde, Imperial County! 



luniger Mannerheim 1853 



REFERENCES 



BLACKWELDER, R. E. 



1931. The Sphaeridiinae of the Pacific Coast. Cole- 

 optera, Hydrophilidae. Pan-Pac. Ent., 8:19-32. 

 BOVING, A. G., and F. C. CRAIGHEAD 



1931. An illustrated synopsis of the principal larval 

 forms of the Order Coleoptera. Ent. Amer., 11 NS. 

 (1-4):1-351, incl. 125 pis. 

 BOVING, A. G., and KAI L. HENRIKSEN 



1938. The developmental stages of the Danish Hydro- 

 philidae (Ins., Coleoptera). Vidensk. Medd. fra Dansk 

 naturh. Foren., 102:27-162, 55 text figs., many com- 

 pound. 

 FALL, H. C. 



1901. List of the Coleoptera of southern California, 



with notes on habits and distribution and descriptions 



of new species. Occ. Pap. Calif. Acad. Sci., 8:1-282. 



1924a. Some notes on Cercyon, with descriptions of 



3 new species. Psyche, 31:247-253. 

 1924b. New species of North American Hydrobiini. 



Jour. N.Y. Ent. Soc, 32:85-89. 

 1930. On Tropisternus sublaevis Lee. and T. quad- 

 ristriatus Horn. Ent. News, 41:238-240. 

 HORN, G. H. 



1873. Revision of the genera and species of the tribe 

 Hydrobiini. Proc. Amer. Philos. Soc., 13:118-137. 

 1890. Notes on some Hydrobiini of Boreal America. 

 Trans. Amer. Ent. Soc, 17:237-278, pis. 3-4. 

 HRBACEK, JAROSLAV. 



1950. On the morphology and function of the antennae 

 of the central European Hydrophilidae (Coleoptera). 

 Trans. Roy. Ent. Soc. London, 101:239-256, 17 text 

 figs. (Note that Hrbacek uses the term Hydrophilidae 

 in the broad sense, to include the Hydraenidao and 

 Spercheidae. Also that his use of the names Hydrous 

 and Hydrophilus are equivalent to the Hydrophilus 

 and Hydrochara, respectively, of the present article.) 

 LEECH, H. B. 



1946. Remarks on some Pacific Coast species of 

 Tropisternus (Coleoptera: Hydrophilidae). Canad. 

 Ent., 77:179-184, 5 text figs. 

 1948. Haliplidae, Dytiscidae, Gyrinidae, Hydrophilidae, 

 Limnebiidae. In Contributions toward a knowledge of 

 the insect fauna of Lower California. No. 11, Cole- 

 optera. Proc. Calif. Acad. Sci., (4), 24:375-484, pis. 

 20-21. 

 1950. New species and subspecies of Nearctic water 

 beetles. Wasmann Coll., 7:243-256, 6 text figs. 

 D'ORCHYMONT, A. 



1921. Le genre Tropisternus. I. (Col. Hydrophilidae). 

 Ann. Soc. Ent. Belg., 61:349-374. 



1922. Le genre Tropisternus. n. (Col. Hydrophilidae). 

 Ann. Soc. Ent. Belg., 62:11-47, 4 text figs. 



1928. Revision des Neohydrophilus americains. Bull. 



& Ann. Soc. Ent. Belg., 68:158-168. 

 1938. Contribution a l'etude des Palpicornia. XH. Bull. 



& Ann. Soc. Ent. 3elg., 78:426-438. 



1942a. Revision des Laccobius americains. (Coleoptera 

 Hydrophilidae Hvdrobiini). Bull. Mus. Roy. Hist. Nat. 

 Belg., 18:1-18, 10 text figs. 



19426. Contribution a l'etude de la tribu Hydrobiini 

 3edel specialement de sa sous-tribu Ilydrobiae. Mem. 

 Mus. Roy. Hist. Nat. Belg., (2), 24:1-68, 4 text figs. 



1946. Notes on some American Berosus (s. str.). Bull. 

 Mus. Roy. Hist. Nat. Belg., 22:1-20, 11 text figs. 

 RICHMOND, E. A. 



1920. Studies on the biology of the aquatic Hydrophili- 

 dae. Bull. Amer. Mus. Nat. Hist., 42:1-94, pis. 1-16. 

 SHARP, D. 



1882. Haliplidae, Dytiscidae, Gyrinidae, Hydrophilidae. 

 In Biologia Cent. -Amer., Insecta, Coleoptera, 1(2): 1- 

 116, pis. 1-3, 4 partim. 



1883. Revision of the species included in the genus 

 Tropisternus. (Fam. Hydrophilidae). Trans. Roy. Ent. 

 Soc. London, 1883, (2):9 1-117. 



TODD, A. C. 



1942. A new parasitic nematode from a water scavenger 



beetle. Trans. Amer. Micr. Soc. , 61:286-289, 4 text figs. 



1944. Two new nematodes from the aquatic beetle 



Hydrous triangularis (Say). Jour. Parasit., 30:269-272, 



incl. 1 pi. 



WILSON, C. B. 



1923a. Life history of the scavenger water beetle, 

 Hydrous (Hydrophilus) triangularis, and its economic 

 relation to fish breeding. Bull. Bur. Fish., 39:9-38, 

 22 text figs. 

 19236. Water beetles in relation to pondfish culture, 

 with life histories of those found in fishponds at 

 Fairport, Iowa. Bull. Bur. Fish., 39:231-345, 148 text 

 figs. 

 WINTERS, F. E. 



1926. Notes on the Hydrobiini (Coleoptera - Hydrophili- 

 dae) of Boreal America. Pan-Pac. Ent., 3:49-58. 



1927. Key to the subtribe Helocharae Orchyro. (Cole- 

 optera — Hydrophilidae) of Boreal America. Pan-Pac. 

 Ent., 4:19-29. 



Family HYDROSCAPHIDAE 



These tiny staphylinidlike beetles, about 1 mm. long, 

 are aquatic and live among filamentous algae. The 

 family was proposed for the one described North 

 American species, Hydroscapha natans LeConte; 

 Palaerctic species were added later. Hydroscapha is 

 the only genus. 



The affinities of Hydroscapha are still not clear. 

 Besides serving as the type of the subfamily Hydro- 

 scaphinae Boving, it has at various times been in- 

 cluded with Limnebius (then in the Hydrophilidae), 

 in the Scaphidiidae, and in the Trichopterygidae (now 

 Ptiliidae). In 1950 Crowson included both it and 

 Sphaeriidae in the superfamily Staphylinoidea. In 

 1954 he suggested that these two families, with 

 Lepiceridae, might form a fourth suborder of the 

 Coleoptera. 



Both adults and larvae (fig. 13:42a-d) may be found 

 abundantly in suitable streams, especially on algal- 

 covered rocks in the marginal shallows. However, they 

 are remarkably tolerant; La Rivers (1950:68) records 

 finding them on December 29, 1946 in Nevada: "A 

 quite populous colony was located in the icy Amar- 

 gosa river just south of Beatty in moderately swift, 

 rough water which froze at the banks each night. 

 Individuals were found clinging lethargically to the 

 undersurface of rhyolite stones well-grown with thin 

 algal layers." On March 31, 1953, I found them 



