BY THOMAS G. SLOANE. 225 



^a6. — Queensland, Dawson River (Barnard); N.S. Wales, 

 Mudgee (Macleay), Lachlan River (Castelnau), ISTarrandera 

 District (Sloane). 



Genus Teratidium. 



In his description of the genus Teratidium, Mr. Bates remarked r 

 " The extraordinary insect for which this new genus is necessary, 

 agrees with Monocentrum only in the absence of the usual tooth 

 or teeth of the anterior tibife above the apical one ; but the 

 excessive dilatation of the terminal joint of the maxillary (as well 

 as the labial) palpi and the very short faint frontal grooves, form 

 very distinct and peculiar characters." After reading this, one 

 wonders whether Mr. Bates was acquainted with Monocentrum 

 in nature; a specimen of M. longiceps, Chaud., is in my possession, 

 and it has the maxillary palps very securiform, their terminal 

 joint being quite as securiform as, though a little smaller than, 

 the labial. 



The following diagnosis of the genus gives some features not 

 noticed in the original description : — 



Head constricted posteriorly, the constriction very strong 

 behind the mentum, suborbital channels and orbits; part of head 

 before posterior constriction transversely subquadrate ; vertex 

 without longitudinal sulci, convex, declivous to eyes ; a wide 

 sulciform impression extending backwards along upper margin of 

 eyes to neck, and dividing vertex from eyes and orbits; supra- 

 antennal plates large, prominent, declivous, not longitudinally 

 sulcate; clypeus strongly declivous, not divided in middle from 

 front, defined on each side by a light linear sulcus (frontal sulci); 

 eyes deeply set in orbits, these large and more prominent than 

 the eyes ; suborbital channels wide, short, single. Maxillary and 

 labial palpi with two apical joints similar in shape; penultimate 

 joint shorter than terminal. Elytra impunctate ; lateral margin 

 upturned, reflexed and widely rounded at humeral angles ; punc- 

 tures of base placed not on basal declivity, but in a depression just 

 behind the declivity; inflexed margin narrow behind first ventral 



segment. 



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