218 Rey. H. Clark on the Dytiscidee of Australasia. 
ribus subparallelis; elytris thorace sublatioribus, lateribus sat late mar- 
ginatis, ad apicem sinuatis, apicem versus swbdentatis, apicibus ipsis 
penitus conjunctis, $triis ad suturam haud obsoletis, ad latera latis et 
profundis; corpore subtus nigro; pedibus nigris, posticis rufo adumbratis. 
Long. corp. 6-62 lin., lat. corp. 3 lin. 
A much smaller and comparatively broader insect than E.rivularis; 
the colour is of a less piceous, more metallic tinge; the apex of the 
elytra is rather more deeply emarginate ; the elytra touch each other 
at the suture almost to the extreme apex. 
It is a trifle larger than H. oblongus of Reiche, and may be sepa- 
rated from it by its rounded emarginations at the apex of the elytra. 
I have received specimens from Moreton Bay. Mr. Bakewell’s 
collection contains examples from the same district. 
A form closely allied to this, but which may possibly prove to be 
distinct, is in my cabinet; it has a manifestly smaller scutellum, is 
not so large as the larger examples of Z. latior, and broader than 
the smaller form, and appears, so far as I can infer from four ex- 
amples, to be uniform in character. 
E. latior is a perplexing species : after much examination, I believe 
that it will hold good as defined above; and that it is able, more 
than its congeners, to some little variation in size. 
d. #. rivularis, n. sp. 
E. oblongo-ovalis, valde depressus, ceneo-, haud nigro-metallicus, ad mar- 
gines elytrorum thoracisque viridi-zneus ; capite et thorace levigatis, 
subtilissime vermiculatis; scutello haud parvo, triangulari; elytris 8- 
striatis, externis 1ma, 2nda et 3tia profundis, 8 ad suturam penitus ob- 
literata; elytris apicem versus dehiscentibus, ad apicem emarginatis, 
haud acuminatis; corpore subtus piceo; pedibus rufo-nigris, anticis 
piceis vel zeneo-piceis. 
Long. corp. 7-8 lin., lat. 8-33 lin. Ad apicem corporis 1 lin. elytris haud 
defensa. 
A striking and handsome species, which manifestly on some occa- 
sions has been found in abundance, and has been sent to England by 
Mr. Wilson and other friends of Mr. Bakewell. 
When compared with other Australian species, it is distinctly larger 
than all, of a dark metallic lustre, the margins both of thorax and 
elytra being green, and this margin being in a continuous line, not 
slightly angulated at the junction of the thorax and elytra as in the 
species Reichii and assimilis. There appears to be in it no tendency 
to variation either in structure or colour. The scutellum (the size of 
which appears to have an importance in the group) is uniform ; and, 
in all the examples before me from Mr. Bakewell’s cabinet and my 
a 
