On Aquatic Carnivorous ColeojJtera or Dytiscidce. .S83 



354. Hyphydrus lyratus, Schartz, M.C — Oblongo-ovalis, sat latus et convexus, 

 dense aequaliter punctatus, subtus ferrugineus, supra rufo-testaceus, prothorace basi 

 medio nigricante, elytris longitudinaliter fusco vel nigro-signatis, stria discoidali 

 ad basin sat distincta. Long. 4^, lat. 3 m.m. 



Mas, fortiter punctatus, sat nitidus, tarsis quatuor anterioribus dilatatis et 

 deplanatis, abdomine segmento baaali medio spina crassiuscula oblique erecta, 

 segmento apicali medio quadrato-impresso, apice summo bi-denticulato. 



Fern., anterius angustior, opaca, subtiliter punctata, elytris versus latera fovea 

 elongata impressa. 



This species ajij^ears to be a variable one. Hyphydrus nigro-notatus, Clk., is the 

 Formosan variety of the species. 



Australia, Formosa, China, New Guinea, Pulo-penang. (Sidney, Port Denison, North- West Australia ; 

 Dorey). 44. 



SS."). Hyphydrus xanthomelas, Regt. Ann. Soo. Fr. 1877, p. Ixxx. — Oblongo- 

 ovalis, sat latus et convexus, piceus, capite et prothoracis lateribus ferrugineis, 

 elytris nigricantibus testaceo-signatis, dense sequaliter punctatus, elytris stria 

 discoidali ad basin sat distincta. Long. 4^, lat. 2| m.m. 



Mas, fortiter punctatus sat nitidus, tarsis quatuor anterioribus sat dilatatis et 

 deplanatis ; abdomine segmento basali margine posteriore medio acute denticulato, 

 apicali medio leviter longitudinaliter inipresso, apice summo bi-denticulato. 



Fern., r 



This species is very closely allied to IL lyratus, but the intermediate tarsi are 

 not so much dilated, and the male sexual abdominal characters are less developed ; 

 the darker colour is perhaps not constant ; indeed M. Regimbart's description 

 indicates an insect less marked with black than the one I have described — the only 

 one I have seen. 



Philippine Islands, (ManDla). 45. 



356. Hyphydrus decem-maculatus, Wehncke, Stet. Zeit. 1877. p. 151. — An^uste 

 ovalis, sat convexus, piceus, capite ferrugineo plus minusve infuscato, elytris 

 ferrugineo-maculatis ; confertira fortiter aequaliter punctatus, elytrorum stria 

 discoidali obsoleta. Long. 4^, lat. 21 m.m. 



Mas, trochanteribus anterioribus valde elongatis, subtus sinuatis, dextro apice 

 acuminate, sinistro apice dilatato ; tarsis anterioribus leviter, intermediis fortiter 

 dilatatis et deplanatis. 



Fern., paulo minor, pedibus simplicibus. 



This species is variable in the colour. The structure of the male trochanters, 

 which is different on the two sides of the body, is highly remarkable. 



Australia, (Cape York, Rockhampton). 46. 



