132S COLEOPTERA 



regular, impunctate striae, which barely touch the base ; interstices 

 simple, not convex, without apical plicae. Legs moderately elon- 

 gate, tibiae with short setae ; middle and hind tarsi feebly furrowed 

 above. 



Length, 4 ; breadth. If lines. 



Dyer's Pass, Canterbury. I am indebted to Mr. Suter for two 

 males and one female. 



2431. Z. rufipes, ns- Black, shining ; legs, antennae, labrum, 

 and palpi ferruginous. 



Eather smaller than the typical species ; the head with two 

 obvious, transversal, interantennal impressions ; eyes more, almost 

 quite, prominent ; the thorax more quadrate ; the sides slightly and 

 gradually narrowed, but not sinuate, behind the middle, posterior 

 angles rectangular but not acute, basal impressions narrow and 

 elongate, quite distinct ; elytra subovate, more sharply striate, 



J . Length, 3f ; breadth. If lines. 



Mr. G. Y. Hudson sent me a specimen, mounted on cardboard, 

 some time ago. I do not know where he found it. 



Group-HYDROPORID-ffi. 



(Bidessini.) 



Hmd coxa soldered completely to the ventral segments, so that 

 the undersurface of the body from the front of the metasternum to 

 the hindmargin of the third ventral segment consists of one rigid 

 piece. This character distinguishes the group from all other 

 beetles. 



The posterior articular cavities are not contiguoits, and are not 

 protected by the coxal processes ; they open directly on the under- 

 surface of the coxae, and are separated from one another by the 

 coxal processes, which are completely adpressed to the level of the 

 ventral segments. 



The hind coxae are always large, with greatly-arched anterior 

 border. This development of the coxse is sometimes extreme. 



In HuxeUiijdriis the prosternum is less reduced than in any of 

 the other genera. In Bidessus and Huxelhydrus the slender hind 

 tibiae are a little bent near the base, and become a little thicker 

 towards the apex. 



Bidessus. 



{Sharp ; Aquatic Colcop., p. 344.) 



Prosterncd process longer than broad, parallel-sided, but with a 

 more or less acute extremity, which attains the metasternum ; inter- 

 coxal process of metasternum not attaining the mesosternal fork, 

 so that when the prothorax is taken away it may be seen that the 

 middle coxae touch one another ; posterior tihice with the basal por- 

 tion much more slender than the apical one. Coxal Lines longer 

 than prosternal process. Hind coxae longer than broad, under- 



