394 KEVISIOX OF THE AMYCTERIDES, 



Head with supraorbital tubercles and generally frontal gTanules or tuliercles. 

 Rostnim short, about as wide as head, deeply excavate above, with the cljTieal 

 plate more or less exserted; with a prominent tul)ercle on each lateral margin, 

 and in most species with a pair of large basal tubercles, corresponding in posi- 

 tion to tlie internal ridges. Antennae slender; scape long. Ej'es rotundate or 

 subrotundate, rather coarsely faceted. Prothorax shaped as in Acantholophus, 

 the apical margin more or less produced above; witliout ocular lobes; disc with 

 median and sublateral areas separated by the submedian rows of tubercles; 

 lateral margins tuberculate, the tubercles either fine or two in number, out- 

 wardly projecting. Elytra elongate, narrow in d", broader in $ ; apex more or 

 less deeply emarginate and bimucronate ; base contained between the advanced 

 ends of the third interstices; disc striate punctate with two or three rows of 

 tubercles, the third row sometimes reduced to a single infrahumeral tubercle (U- 

 spine. Venter more or less flattened in c?, convex in ?; the intermediate seg- 

 ments moderately long;' the apical segment without excavation. Legs moderately 

 long and slender; tarsi of moderate length. 



Though in general appearance resembling the smaller species of Acantho- 

 lophus, the present genus may be readily distinguished by the relation of the 

 bases of the prothorax and elytra. The arrangement of the rostral tubercles 

 is also different, the large basal pair not being found in Acantholophus. The 

 presence of these is however not absolutely constant in Hi/horrlu/nchua, and the 

 arrangement of the head and rostral tubercles affords good specific features. 



The species are very similar in appearance but are all readily separat(>d, 

 partly on the characters of the aljove-mentioned tubercles, but partly also on 

 the arrangement of tlie lateral protlioraeic and of the elytral tubercles. 



Ifistori/. — The genus Hi/borrhi/nchus was proposed in 1865 by William 

 Macleay for the reception of one species previously placed in Acantholophus — 

 coenoinia Bohem. — and of three new species — fHrcatiu<, mncitlatus and rufjosus. 

 Subse(|uently, in 186(), Macleay ndiled 4 further species — masterni, prodigus, 

 rnissiu.wiihix and hicornutm. 



II. coenosus Bohemann was originally described (8chonh. Gen. S|)ec. Cui'c., 

 vii. (1), 1843, ]). 80) under the genus Amyctenis. In 1846 Schonherr included 

 it in Acantholophtts, then first formally described (Mantissa secunda Cure., ji. 

 57), tliougli the species is not mentioned by name, only the number (50) of its 

 place in the original i)ublication l)eing given. The species was also included in 

 tlie table of the genus Acdiitholn/ihii.v given bv 0. T?. Waterhouse (Ti-ans. Ent. 

 Soc. N.S., iii., 1854, p. 2). 



This species T would now select as the genotype of H;iborrhi/)ich)(.--\ not 

 because it is the earliest described species referable to the genus, but because 

 Macleay in describing H. fiircatus (the first species described l)y him) based his 

 description on the sexes of two species, one of them being the species (muculatu-'f) 

 next in order. The ciuestion of the allotment of these names is discussed under 

 11. fwreatus. 



The third species (ruijosus) is here made the type of a new genus. 



Of the 4 species added )iy Macleay in ISIifi, two — ma.'itcrni and craftrfiuscuhi-f 

 — are now removed to a new genus. 



Only one species lias been described of recent years — auric^ena Blackb. 

 (Trans. Roy. Soc. S. Aust., 1809, p. 80). This 1 liave already leinoved to 

 Cuhlcorrhj/nchiis (Proc. Linn. Soc. N.S. Wales, 1016, xli., part 3, p. 452). One 

 new species is added in the present paper, making a total of 6 species at jiresent 

 known. Acantholophus convexiusculns Macl. was provisionally referred to 

 Ihlhorrhtinchus in tlu^ pi'cvious part of this revision. It is here referred to a 



