HYDROMETRHLE. 565 



thick yellow line, the sides of this anterior region much thickened, 

 curved in and raised posteriorly ; the tubercle on the hinder angles 

 large ; the undercurved side margins from under the hinder angles 

 to the constriction with a yellow line, broadest posteriorly ; the disk 

 with a very slight, central, longitudinal keel. Elytra black-brown, 

 with blueish shades in patches, the nerves clothed with golden, scale- 

 like hairs ; Sternum ; Prosternum yellow, with a large black spot not 

 reaching to the anterior margin ; Meso- and Metasternum black, the 

 sides with longish, appressed, silky, white or brassy hairs, the part 

 next the pronotum, visible from above, less lustrous, and the black 

 colour in certain lights divided into 2 lines ; mesosternum in front 

 depressed into a narrow longitudinal channel, in which rises a fine 

 keel, which extends along the metasternuni ; from each side of this 

 keel anteriorly another similar one diverges at a considerable angle, 

 but they cease beyond the middle of the segment ; the inner side of 

 the sheath of the 2nd pair of coxa3 with a silvery line, the sheath 

 itself beneath with a large triangular yellow spot ; Metasternum ; 

 in the J the central keel is replaced by a large, transverse, orange 

 tubercle; in the ? the keel is sometimes yellowish, and in the 

 middle the colour spread out, sometimes also the middle is slightly 

 raised ; the sheath of the coxa? marked as in the mesosternum. 

 Legs; 2nd pair longest; coxae black, beneath partly or wholly 

 yellow ; fulcra yellow, with a brown or black spot ; thighs ; 1st pair 

 black, on the basal \ inside and beneath yellow, the colour ending 

 in a point \ way up, or faintly continued to the apex (viewed from 

 above the basal \ internally appears diagonally yellow) ; the outer 

 side with a narrow, obscure, yellow line; 2nd and 3rd pairs in 

 length subequal, brown above, yellow-brown beneath, apex black ; 

 tibicB brown, paler beneath; 2nd pair longer than the 3rd; tarsi 

 black ; the tibiae and tarsi much longer on the 2nd than on the 3rd 

 pair. 



Abdomen above, dull black, the middle with a gray line ; the pos- 

 terior margin of the 6th segment, in the <$ , reddish-yellow ; Con- 

 nexivum with a reddish-yellow line down the middle, broader towards 

 the end, the side next the abdomen black, the margin with a brown 

 line. Underside with a slight middle keel ; ^ black, with a brownish 

 line on the keel, the 6th segment posteriorly yellow, the posterior 

 margin very concave, and in the middle a deep round notch ; $ black, 

 the middle with a dull yellowish line widened on the 5th and 6th 

 segments. Genital segments; above, black, the 1st convex, 



