On Aquatic Carnivorous Coleoptera or Dytiscide. 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 the 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 underside 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. howitti. 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 Southern Australia. 414. 
446. Macroporus lateralis, n. sp. -—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. 5%, lat. 3$ m.m. 
The only individual I have seen seems to indicate a species distinct from H. 
hamatus ; it is rather largerandis 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, 
erebrius 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. 64, lat. 33 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, 
