BY THOMAS (J. SLOANB. 429 



having been characterised before the other two ; •'•' but it is with 

 reluctance I adopt it, seeing that it was originally formed for a 

 species (P. impressijrons, Chaud.) f said to be from New 

 Zealand, which may differ considerably fi'om Australian species. 

 The genus, as constituted in this paper, may be broken up into 

 groups thus : — 



A. Metasternal episterna short ... {Prosopoc/mus ol Chaudoir.) 



B. ]Metasternal episterna elongate. 



a. Elytra with fifth and seventh interstices enclosing sixth 

 at apex ( Ophryostemus of Chaudoii'. ) 



b. Elytra with sixth and eighth interstices enclosing 

 seventh at apex (Cene^is of Chaudoir.) 



The form of the metastei-nal episterna has no weight in 

 Siniodontuts, therefore I think it should not be given undue 

 prominence here ; the interstitial character also appears to me 

 of subordinate importance. It may be noted here' that the 

 genera Simodontus, Hormochihis, and SetaUmorpJia are differen- 

 tiated from one another, and from Prosopogmus on very doubtful 

 grounds. 



Prosopogmus austrinus, n.sp. 



Oval, depressed ; prothora.x sul^quadrate, posterior angles 

 sharply rectangular ; elytra striate, shoulders feebly dentate ; 

 metasternal episterna short. 



Piceous black ; legs, antenna?, mouth-parts and sides of elytra 

 towards apex piceous red. 



Head moderate ; front strongly impressed ; the impressions 

 short, veiy divergent behind, curved inwards at posterior 

 extremity, eyes convex, not deeply set in orbits. Labrum lightly 

 emarginate. Prothorax subquadrate (2-2 x 2-6 mm.), depressed 

 on disc and towards base, lightly declivous on anterior three- 



* Bull. Mosc. 1865, III. p. 93. 

 + It seems as well to point out here that Captain Broun is in error (Man. 

 N.Z. Col., 1880, p. 30.) in makmg the comparison of P. impressi/rons in de 

 Chaudoir's original description as being with Trichosternus guerini, Chaud., 

 { = Plaiysnia australasve, Guer.) instead of with Feronia (Notonomus) 

 australasicH, Dej. ; the latter being the species de Chaudoir leferred to. 



