On Aquatic Carnivorous Coleoptcra or Dytiscidce. 417 



This species is closely allied to Hydroporus howittii, but it is always different 

 in colour, and may be readily distinguished by the more even punctuation of the 

 elytra, the punctures being more distinct at tlie base, and less dense towards the 

 extremity ; the colour is blackish, with the head red, the thorax varying from red 

 to fuscous black, the elytra black, often with the outer margin and two longitudinal 

 stripes yellow, the undei'side blackish more or less diluted with red. The male has 

 the front and middle tarsi dilated ; the third joint of the front one being rather 

 larger in comparison with the basal ones than in H. howittii, the claws are less 

 unequal than in H. howittii. There are two forms of the female, one with the 

 surface differing but little from that of the male, while the other is dull and more 

 densely punctured and pubescent. 



Tasmania and Soutliern Australia. 414. 



446. Macroporus lateralis, n. sp. i^ — Ovalis, robustus, tenuiter pubescens, dense 

 punctatus, subopacus, fusco-ferrugineus, capite, pedibus thoraceque rufescentibus, 

 hoc medio late infuscato, elytrorum limbo fusco-testaceo, antennis rufo-fuscis basi 

 rufo ; coxis posterioribus sat fortiter punctatis ; abdomine obsolete punctato. 

 Long. 5f, lat. 3 A m.m. 



The only individual I have seen seems to indicate a species distinct from H. 

 hamatus ; it is rather larger and is intermediate in appearance between the two female 

 forms of that species ; the tarsi are rather differently formed, the terminal joint on 

 the front and middle ones being less elongate than in H. hamatus. This individual 

 had been named H. gardnerii by the late Mr. Clark. 



West Australia. 415. 



447. Hydroporus gardnerii, Clk., M.C. — Ovalis, robustus, tenuiter pubescens, 

 crebrius sat fortiter punctatus, subnitidus, nigricans, capite thorace, antennis pedibus 

 que rufis, antennis versus apicem, vertice, et thorace anterius et posterius fuscis, 

 elytris margine sordide pallido ; coxis posterioribus fortiter punctatis ; abdomine 

 evidenter punctato. Long. Q\, lat. 3f m.m 



The front and middle tarsi are dilated in both sexes ; but are broader in the 

 male than in the female, and in the former sex the claws of the front ones are 

 unequal, the anterior one being rather shorter and more curved than the hinder one. 

 There are two forms of the female — a dull one and a shining one. The species 

 is distinguished from H. hamatus, by its larger size and coarser punctuation. It 

 varies in colour, but probably never has stripes on the elytra ; these are in some 

 cases infuscate yellow, while in others the yellow colour is limited to the side 

 margin. The tarsi are much broader in the female than they are in that sex of H. 

 hamatus. 



Tasmania, New South Wales, (Adelaide). 416. 



