On Aquatic Carnivorous Coleoptera or Dytiscide. 383 
354. Hyphydrus lyratus, Schartz, M.C.—Oblongo-ovalis, sat latus et convexus, 
dense zequaliter punctatus, subtus ferrugineus, supra rufo-testaceus, prothorace basi 
medio nigricante, elytris longitudinaliter fusco vel nigro-signatis, stria discoidali 
ad basin sat distincta. Long. 43, lat. 3 m.m. 
Mas, fortiter punctatus, sat nitidus, tarsis quatuor anterioribus dilatatis et 
deplanatis, abdomine segmento basali medio spina crassiuscula oblique erecta, 
segmento apicali medio quadrato-impresso, apice.-summo bi-denticulato. 
Fem., anterius angustior, opaca, subtiliter punctata, elytris versus latera fovea 
elongata impressa. 
This species appears 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. 
355. Hyphydrus xanthomelas, Regt. Ann. Soc. Fr. 1877, p. Ixxx.—Oblongo- 
ovalis, sat latus et convexus, piceus, capite et prothoracis lateribus ferragineis, 
elytris nigricantibus testaceo-signatis, dense «qualiter punctatus, elytris stria 
discoidali ad basin sat distincta. Long. 43, 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 impresso, apice summo bi-denticulato. 
Fem., ? | 
This species is very closely allied to H. 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, (Manilla). 45. 
356. Hyphydrus decem-maculatus, Wehncke, Stet. Zeit. 1877. p. 151.—Anguste 
ovalis, sat convexus, piceus, capite ferrugineo plus minusve infuscato, elytris 
ferrugineo-maculatis ; confertim fortiter eequaliter punctatus, elytrorum stria 
discoidali obsoleta. Long. 44, lat. 2§ m.m. 
Mas, trochanteribus anterioribus valde elongatis, subtus sinuatis, dextro apice 
acuminato, sinistro apice dilatato; tarsis anterioribus leviter, intermediis fortiter 
dilatatis et deplanatis. 
Fem., 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. 
