12:i Mtmntrs uj the Induiii Miisriim. (Vol,. VII, 



Tiie niiMt priinitivc ttpucicit of the AuMtrulinn Kcgion liclong totliegetuiH MtiHtochdug, 

 lik«' the Oriental A'/»i,'»/</i«*n»i«, i-ontuins hutli .syninn'trinil aiul more or leati 

 iietricul sperie.s. The Mihgetiera Phnntclulits uiiti Mii.stiic/nluM, whiih with ouc 

 exreption (.W. ftectntufrra. Heller, from New (iiiinea) are (-Mnlined to Australia, contain large 

 nml rohuHt Hynirnetrii-al inhct'ts. The subgenera AnaUulifs and Cvtcjtttt, whii-h with one 

 exit'ption (.1/. nugtmliensia inmx Australia) are found in the islands north of Australia, 

 contain smaller and often slighter insects winch are ahno>t always more or less asymmetrical. 

 Of the two spwicii of Episfthenuii inhabiting Ceylon the dominant one is slightly 

 asymmetrical, the other, which i» syninietricnl, being clasely allied to it, but much lens 

 abundant and of smaller size. In Australia, on the contrary, the various symmetrical 

 .sprcies are dominant, the asymmetiical Ma.sliMliilus (Annitic/un) iiuslrtthfiism being 

 comparatively rare ; which suggests that M. aiislrciliengia is a comparatively recent 

 itiipMrtation ond has not been derived «lirectly from its symmetrical compatriots. This 

 ii-,:f.tion is supjuirted by the fact that M. (luslntliensig is much more closely related to 

 I'apuan than to Austmlian spiiies, being indeed one of the most highly a.symnietrical 

 tnendiers of its genus, and by the fact that it has been recorded from New (tuinea as well 

 as from Australia. 



The genus Mtistitf'hiln.s probably rej)rcsents the primitive st(K-k fr»»m which the genera 

 Jjabirniis (with PnttitiniMiM his), (iniinliis and Psiitdi jusfilnims (with Tdri/iiinnis) have been 

 derived. 



In l,<iliu'niis sj)e<iali7.aiioii allcct^ mainly the tiHtasH'inum, aj»parently in a>-'Mi;jti'tn 

 with the wings, which tend to lose their normal function and iloubtless to become more 

 efficient stridulating organs at the same time. In the mo.st highly specialized members of 

 the genus, which a])pear to be confined to the Moluccas, the elytra are united in the middle 

 line, species with separate elytra being apparently to be conlined to New (iuinea. the 

 Aru Islands, etc. 



ProtomocwUta apiMMi- in iiavi- bmi derived from the simpler forms of I^biennx. li> 

 dentition is reduced, in which respect it is the most highly specialized of all the .species 

 with a nuxlified metasternum. But the elytra are not united nor ilo they show any tendency 

 to become ovate. The genus iK-curs in the Solomon Islands and has been recorded from the 

 Miilucj-as, OS well as froni the I.slands inhabited by the simpler fr)rms of Ijobienus. 



The genus Gonatns constitutes a .second line of descent from MnslnchUns. The 

 metasternum, wings ond elytra are always normal ; but the mondibles beconje very 

 stronciv asymmetrical, anti the posterittr margin of the mentum verj' strongly arched, in 

 ' iaiized forms. The progressive .stages of this developnient ore still pre.serve<l in 

 ;;hly specialize*! species. The nn»st primitive species of all, (i. minimus, appears 

 to he conluicd to New (Juinea and its neighbouring islands : but (i. pumilio, the species 

 mo^t closely allied to it, although occurring there ap])ears to be centred in the Moluccas. 

 .Much larger ami more abundant than either arc (i. sr/irlioniji, (i. germari ond (i. nariculatnr, 

 which must In* regarde*! os the dominont species of the genus, (i. schfUongi is .somewhat 

 more primitive than either of the others, and is confine<l to New (Guinea, the other two 

 being centred in the Moluccas, though recorded from New (Juinea and from Java and the 

 Philippines also. 



