3. Elytra with regular series of punctures clearly trace- 

 able in apical one-fourth to one-third, and laterally with 

 at least 3 rows of closely spaced regular punctures 

 from apical margin to near umbone; elytra, and pronotum 

 except discally, usually testaceous; California to Oregon 



imbellia (LeConte) 1861 



— Elytra with lateral rows of serial punctures not regular 

 and clearly defined, but confused with coarse punctures 

 of interspaces; pronotum and elytra piceous or black, 



paler laterally; California to British Columbia 



pacifica Leech 1948 



345 

 Leech and Chandler: Coleoptera 



10. Elytra more coarsely punctate; salt marsh and saline 

 pools, coast of California and up estuary of Colorado 

 River hamiltoni pacificua Leech 1950 



— Elytra more finely punctate; saline waters, Death 

 Valley, California hamiltoni pyretua Leech 1950 



11. Smaller species, 3.5-4.5 mm. long; hind edge of hind 

 femora simple; Central Valley of California 



flatiuaculua (Motschulsky) 1859 



— Larger species, 5-6 mm. long; hind edge of hind femora 

 of male raised and slightly produced at middle; Cali- 

 fornia to British Columbia . . . diffuaua (LeConte) 1855 



Key to the California Specie* of Enochrus 

 Adults 



1. Fifth abdominal sternite with a small apical emargi- 

 nation, from which projects a differentiated fringe of 

 flat golden ciliae 2 



— Fifth abdominal sternite entire apically, not emarginate, 

 without differentiated fringe of flat ciliae 8 



2. Last 2 segments of maxillary palpi of equal length, or 

 last longer than penultimate 3 



— Last segment of maxillary palpi shorter than penultimate 



5 



3. Head luteous in front of eyes, elsewhere black; 

 presternum not carinate; smaller species, 3.5-4 mm. 

 long; pronotum black, sides and parts of anterior and 

 posterior margins luteous; California 



cuspidatus (LeConte) 1878 



— Head entirely black, or vaguely narrowly rufopiceous 

 in front of eyes; prostemum with low poorly defined 

 median longitudinal carina; larger species, 4-5 mm. 

 long 4 



4. Head black, pronotum and elytra rufotestaceous; 

 southwest U.S fucatua (Horn) 1873 



— Head, pronotum, and elytra black, usually only front 

 angles of pronotum pale; Pacific Coast, Arizona 

 carinatua (LeConte) 1855 



5. Larger speoies, 4.5-5 mm. long; prosternum not carinate; 

 mesosternal protuberance nearly level, its form some- 

 what obscured by pubescence; California to British 

 Columbia calif ornicua (Horn) 1890 



— Smaller species, 2.75-3.75 mm. long; prosternum 

 carinate; mesosternal protuberance laminiform, acutely 

 prominent anteriorly, not at all obscured by vestiture 



6 



6. Pronotum piceous on disc 7 



— Pronotum entirely testaceous; elytra polished, minutely 

 punctate, except for several more or less evident 

 longitudinal series of coarser punctures; southwest 

 U.S pectoralia (LeConte) 1855 



7. Elytra extremely finely, sparsely punctate, except 

 for serial punctures which stand out contrastingly; 

 pronotum usually broadly piceous, elytra tinged with 



piceous; narrower species; San Diego County 



criatatua (LeConte) 1855 



— Elytra rather densely, moderately coarsely punctate, 

 serial punctures not conspicuous; pronotum usually 

 piceous only at middle of disc, elytra not tinged with 

 piceous; broader species; California to Oregon to Utah 



obtuaiuaculua (Motschulsky) 1859 



8. Dorsal surface black or piceous, sides of head and 

 pronotum often paler; California to Oregon 



conjunctiva (Fall) 1901 



— Dorsal surface testaceous, except for piceous markings 

 on head and sometimes on pronotum; pronotum with 

 4 small black dots as if at corners of a discal quad- 

 rangle 9 



9. Front margin of clypeus evenly arcuate-emarginate , 

 without trace of a secondary emargination at middle; 

 species occurring in brackish or saline water along 

 seacoast, near lower Colorado River, and in Death 

 Valley 10 



— Arcuate front margin of clypeus with a secondary 

 emargination at middle, exposing a preclypeus 11 



Genus Helocharea Mulsant 



Adults 



Elytra with 10 rows of coarse punctures, the rows not 

 impressed as striae; front margin of labrum arcuate in- 

 wards; mesosternal protuberance distinctly longitudinally 

 carinate; length 4-5.5 mm.; California to Baja California 

 to Texas normatua (LeConte) 1861 



Key to Certain California Species of Cercyon 



Adults 



Several species of Cercyon occur under kelp and 

 other debris on ocean beaches, and a few are found 

 in dead grass and other decomposing vegetation 

 beside streams or lakes. Most of the species are 

 strictly terrestrial, though found only in damp places, 

 especially in rotting vegetable matter and in the 

 dung of animals. Preliminary studies by a specialist 

 at the British Museum have shown that the nomen- 

 clature of the species in North America is sadly 

 confused. It is not practicable to give a key to all 

 the species occurring in damp places; the following 

 are found near water. 



1. Form broad, rather flat, head held obliquely; head, 

 pronotum, and intervals of elytral disc rather densely, 

 uniformly punctate, surface shining between punctures; 

 prosternum with at most a very low, weak carina on 

 median line; differentiated metasternal area limited 

 to mid-metasternum; larger species 2.5-3.5 mm. long, 



occurring on sea beaches 2 



— Form oval, convex, head held nearly vertically; head, 

 pronotum and elytral intervals sparsely, finely punc- 

 tate, surface alutaceous; prosternum with a high, 

 sharp, longitudinal median carina; discal elytral 

 striae lightly impressed, closely punctured, lateral 

 series not impressed, consisting only of coarser 

 punctures; differentiated metasternal area limited to 

 mid-metasternum; mesosternal protuberance oval 

 twice as long as wide, flat, punctate; smaller species, 



Fig. 13:41. Hydrophilidae. a, head of an adult representative of 

 Sphaeridi ini to show margin of head hiding base of antenna; b, 

 head of an adult representative of Cercyonini (D'Orchymont, 1919). 



