322 



Leech and Chandler: Coleoptera 



claws of mesotaxsi of male of equal length; larger 



species, 14-16 mm. long; southwest U.S 



atricolor (Aube) 1838 



— Elytra yellow, finely irrorated with black, or black 

 except at apex and around margins; pronotum yellow- 

 ish, usually marked with black; ventral surface largely 

 piceous; mesotarsal claws of male unequal; smaller 

 species, 10-13 mm. long 4 



4. Claws of front tarsi of male elongate, anterior ones 

 1/3 larger than their fellows and longer than claw-bear- 

 ing segment; female with an elongate-oval roughened 

 area on each elytron, from humerus to beyond middle; 

 carina of prosternal process usually black; California 



aniaonychus (Crotch) 1873 



— Claws of front tarsi of male not as long as claw-bearing 

 segment; female without roughened area on elytra; 

 prosternal carina usually pale 5 



5. 3oth claws of front tarsi of male straight, sinuate 

 along lower margin; hind femora pale to almost com- 

 pletely piceous; Nearctic binotatus (Harris) 1828 



— Claws of front tarsi of male short, rather evenly arcuate, 

 anterior ones a little broader medially than their 

 fellows; hind femora pale 6 



6. Anterior claws of front tarsi of male more abruptly 

 sinuate along lower edge, broader at middle than at 

 base; aedeagus of male with apical quarter thinner, 

 more strongly twisted to one side; Pacific Coast north 

 of Los Angeles County hoppingi (Wallis) 1933 



— Anterior claws of front tarsi of male less abruptly 

 sinuate along lower edge, not broader at middle than 

 at base; aedeagus with apical quarter thicker, less 

 strongly twisted, southwest United States, Mexico 

 gutticollis (Say) 1834 



Key to the California Species of Colymbetes 



Adults 



1. Front tarsi of male densely clothed beneath with 

 glandular hairs, but without enlarged suction cups 

 (palettes); undersurface, including legs, black; Pacific 

 Coast, California? seminiger LeConte 1862 



— Frontal tarsi of male with rounded palettes beneath, 

 at least in part 2 



2. Front tarsi of male with 4 rows of similar rounded 

 palettes, but no basal rows of small elongate palettes 

 or of hairs 3 



— Front tarsi of male with 3 rows of rounded palettes, 

 and basal rows of elongate palettes or of hair 4 



3. Form stout, convex; legs rufopiceous. Sculpture of 

 pronotum consisting of irregular impressed lines of 

 varying lengths, few of which join or enclose spaces; 

 metasternal wing at narrowest point behind middle 

 coxa, fully '/£ as wide as hind coxal plate measured 

 along continuation of same line; southern California, 

 San Diego County, San Bernardino County 



strigatus LeConte 1852 



— Form narrower, flatter; legs testaceous, femora some- 

 times tinged with rufous or piceous. Pronotal sculpture 

 vermiculate, most of lines joining and enclosing 

 spaces; width of metasternal wing behind middle coxa 

 less than 1/2 that of hind coxal plate measured along 

 same line; northwest north America, Sierra of California 



(subsp. of) rugipennis Sharp 1882 



4. Protarsi of male with 3 rows of rounded palettes and 

 a basal strip of glandular pubescence 5 



— Protarsi of male with 3 rows of rounded palettes and 

 a somewhat double basal row of smaller elongate 

 palettes, each a little less than half as big as the 

 round ones; San Francisco Bay area, east to foothills 

 of Sierra (species) 



5. Protarsi of male with 3 rows of rounded palettes; 

 apical half of 1st segment with glandular pubescence; 

 elytra of female dull, transverse lines in basal V, broad, 

 very deeply engraved, intervals between being scabrous; 

 Oregon, Humboldt County inae qualis Horn 1871 



Apical third of 1st protarsal segment of male clothed 

 beneath with glandular pubescence; elytra of female 

 shining, sculptured as in male; Monterey County, 

 Napa County ? exaratus LeConte 1862 



Genus Eretes Laporte 



Adults 



The single species occurring in North America is at once 

 recognizable by its narrow form, pale color, size (14 to 

 17 mm. long), and the fact that the elytral margins, from 

 behind the middle to about posterior fifth, are set with 

 short flat spines and fine golden hairs; cosmopolitan; 

 in California, at least as far north as northern Fresno 

 County sticticus (Linnaeus) 1767 



Genus Hydaticus Leach 



Adults 



Length 11.5-14.5 mm.; black, head reddish anteriorly, 

 pronotum black only across base discally, elytra usually 

 with indications of pale vittae (especially in female), 

 often pale across base, and pale laterally; elytra extreme ly 

 finely punctate; northern north America; northern Cal- 

 ifornia ? modestus Sharp 1882 



Genus Acilius Leach 



Adults 



Length 13-15 mm.; yellowish-brown dorsally, elytra irrorated 

 with black, pronotum with 2 transverse discal black bands 

 (fig. 13:16e); elytra of male rather densely punctate, 

 punctures in basal region somewhat lunate; elytra of 

 female (except in var. simplex LeConte) fluted, with 4 

 broad pubescent grooves, outer 3 reaching to humeral 

 area, inner one to a little in front of middle (fig. 13:16/); 

 northern north America, south to San Diego County (simplex) 

 in California . . .semisulcatus abbreviatus Mannerheim 1843 



Key to the California Species of Thermonectus 



Adults 



1. Elytra black, each elytron conspicuously marked with 

 10 or 11 yellow spots of various sizes, lateral spots 

 often connected along elytral margins (fig. 13:16^); 

 length 12-14 mm.; southwest U.S., Central America, 



San Diego County, Riverside County 



marmoratus (Hope) 1832 



— Elytra black to rufopiceous, with irregular marginal 

 longitudinal yellowish marks which may be divided 

 by dark lines or specks; subbasal transverse yellow 

 band present or not (fig. 13:16A); length 9-11 mm.; 

 southern U.S., Guatemala, San Diego County north to 

 Shasta and Lassen counties . . . basillaris (Harris) 1829 



Genus Graphoderus Dejean 



Adults 



Length 13-15 mm.; pronotum black discally along anterior 

 and posterior margins; elytra yellowish, irrorated with 

 black, extremely finely punctate; northern North America; 

 Lassen County occidentalis Horn 1883 



Key to the California Species of Dytlscus 



l.Hind coxal processes broadly rounded or bluntly 

 pointed apically 2 



