568 IIYDROMETRINA. 



Species 6. HYDROMETRA ARGENTATA. 



GERKIS ARGENTATA, Schum. Beitr. 2, 49, 9 (1832); //. Schf. Norn. Eat. 



1, 63 (1835). 



APICALIS, Curt. B. E. xii, 553, 6, pi. 553 (1835). 

 HYDROMETRA H. Schf. Wanz. ix, 68 & 74, t. 301, fig. 932 (1850) ; 



Flor, Rhyn. Liv. i, 740, 6 (1860) ; Fieb. Europ. 



Hem. 109, 12 (1861). 



Above black-brown ; beneath black, with a silvery gloss in oblique 

 aspects. Antenna black. Pronotum with a slight middle keel 

 ceasing on the scutellar process, with a short, dull yellow line 

 in front, posteriorly silvery, shining, the flattened margin of 

 the process with short, silvery shining hairs. Elytra black- 

 brown, in certain lights blue-gray ; sheaths of the middle coxa 

 perceptibly keeled on the outer side. Legs black ; 1st pair 

 of thighs yellow at the base on the inner side. 



Head; sides with a silvery white line. Antenna black ; 1st joint 

 shorter than the 2nd 3rd and 4th together ; 3rd extremely minute ; 

 5th longer than the 2nd. Eyes and Ocelli black. Rostrum black, 

 2nd joint yellowish. 



Thorax. Pronotum; 1st region flat, with a slight keel, the 

 anterior \ of which has a dull yellow line ; the sides incrassated, 

 rounded ; sides of the middle region rounded off, but produced at 

 the hinder angles into a dwarf tubercle ; the undercurved margin 

 in both regions with a narrow yellow line, broadly interrupted at 

 the constriction ; disk flattish, punctate-granulate, with a fine 

 central, bare, silvery, shining keel ; scutellar process more convex, 

 the keel almost imperceptible, the sides and apex rounded, the 

 flattened margin narrow, clothed with shining, silvery hairs. Elytra 

 black-brown, in oblique aspects blue- gray ; nerves with brassy scale- 

 hairs. Wings fuscous-brown, white on the basal 3rd. Sternum 

 black ; Prosternum with a yellowish spot towards each side ; Meso- 

 sternum ; sides viewed from above black, divided into 2 lines by a 

 silvery-gray longitudinal streak ; sheaths of the 2nd and 3rd pairs 

 of coxaa black above and beneath, the posterior margin beneath 

 narrowly yellowish, the outer sides of the 2nd pair perceptibly 

 keeled ; on the inner side a silvery line. Legs ; coxa black, yellow- 



