318 



Leech and Chandler: Coleoptera 



Fig. 13:16. Dytiscidae, adults, a, Deronecfes roffi; b, Deronecfes striatellus; c, Agabus 

 disintegratus; d, Agabus regularis; e, Acilius semisulcatus male; f/ A. semi'su/cotus female; 

 g, Thermonecfus marmoratus; b, Tnermonectus basillaris (Sharp, 1882). 



Anterior (inner) claw of front tarsus of male a little 

 shorter, 2/3 to 3/4 length of outer claw; Sierra of Cali- 

 fornia, north to British Columbia, east to Saskatchewan 



pervicinus Fall 1923 



Claws of front tarsi of male equal in length; California 



hirtellus LeConte 1852 



Key to the California Species of Deronectes 

 Adults 



1. Hind femora densely, evenly punctate throughout 



. 2 



— Hind femora usually closely punctate in posterior 

 half, more sparsely punctate or nearly smooth in front 

 of median row of setigerous punctures 10 



2. Form more broadly rotundate-oval and strongly convex 

 (less noticeably in exi-nius), mid-coxae more widely 

 separated 3 



— Form more elongate and less convex, mid-coxae more 

 narrowly separated 6 



3. Each elytron with 3 lines (sutural, discal, subhumeral) 

 of lightly impressed punctures, discal series twice 

 as far from sutural series as latter is from suture. 

 Hind coxal lines slightly to moderately divergent 

 anteriorly. Undersurface usually black 4 



— Each elytron with a sutural and more than 1 discal 

 line of punctures. The discal series are less distinctly 

 impressed, especially toward base, and are more or 

 less confused with similar interstitial punctures 



posteriorly. Hind coxai lines widely divergent ante- 

 riorly; if continued, they would pass outside the meso- 

 coxae. Undersurface rufous. Rotundate oval, strongly 

 convex species; elytra black, marked with yellow as 

 follows: a transverse posteriorly indented basal spot, 

 2 smaller median spots arranged transversely, and 

 1 or more irregular apical spots (fig. 13:15a); California 

 deceptus (Fall) 1932 



4. Form less convex and less rotundate; median area of 

 elytra (i.e., between discal striae) flattened and 

 slightly depressed. Under surface black, very densely, 

 finely punctate and irregularly wrinkled, opaque. 

 Elytra black with yellow fasciae (fig. 13:156), rather 

 than with spots as in deceptus; California 



exiviius (Motschulsky) 1859 



— Form broader and more convex, elytra not flattened 

 or depressed medially. The undersurface rufopiceous to 

 black, densely, finely punctate, mid-metasternum more 

 sparsely punctate, shining 5 



5. Form more elongate, less obese. Elytra black with a 

 yellow fascia near base, an indistinct median fascia, 

 and vague yellow markings laterally near apex (fig. 

 13:16a). Elytra virtually glaorous; California 6 [U. 

 addendus (Crotch), nee Fall] roffi (Clark) 1862 



— Form more strongly convex. Elytra yellowish, with 

 ante- and postmedian interrupted black fasciae. Elytra 

 finely pubescent; California 6 .. corpulentus (Fall) 1923 



6 Said to occur in California, on the basis of some old specimens 

 in the LeConte collection. All modern examples so determined 

 have proved to be misidentified specimens of deceptus or eximius. 



