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Show 422 MR. H. R. HOGG ON AUSTRALASIAN SPIDERS. [Dec. 2, its eyes as well as in the form of the male palp and epigyne of the female, has almost every intermediate gradation between a moderately curved and quite flat cephalothorax. The two undoubted species of Holconia Thor., II. immanis and II. insignis, differ from Isopeda solely in being the extreme representatives of the series in flatness of the cephalothorax, while in structural features they are otherwise undistinguishable. In the only specimens I can find to attribute to L. Koch's II. dolosa, the cephalothorax is not even noticeably flat, and a northern species, II. subdola Thorell, is only very doubtfully attributed by him thereto. I have therefore amalgamated the genus with Isopeda L. K. In all the genera except Pediana the median eye-area is at least not longer than broad, generally distinctly broader, but in the latter it is longer than broad. For this reason, although the rear row of eyes is clearly procurved, it has been included by M. Simon among the Heteropodece. Isopeda horni mihi belongs to this genus, and two new species from Western Australia bring the number of its members to four. I have not been able to obtain a male of any of my species; but the epigyne of the female is so distinctly of the Isopeda type, that it appears more probable than not that all the males will prove to be provided with a spiral flagellum and drum, and this is the case in P. regina, the type species, as described by Thorell. The first and second pairs of legs are nearly equal in length, and in the larger species are barely Laterigrade in mode of setting. The eye-space is raised lip all round, and, although worthy of a distinctive genus, where it diverges from Isopeda it does so almost more in the direction of Mithurga Thor, than towards Heteropoda Latr. Its beard alone could hardly, I think, entitle Typostola E. Sim. to rank as a separate genus, but the shortness of the palpal spiral distinguishes it from all the species of Isopeda, where the number of turns is generally about ten, but here only three. A primitive Delena from King's Island (Bass's Straits), in which the spiral is quite rudimentary, both stylus and conductor making only a single turn, and the tibial apophysis is single instead of double, also necessitates a new genus. Except in its smaller size, it is otherwise scarcely distinguishable from Delena cancerides Walck., and clearly suggests the direction along which the present modification has been derived. The genera may be separated as follows :- A. The middle eyes of the front row much nearer to one another than to the side-eyes, and clearly larger than the latter. Cephalothorax very Hat and low. Pars cephalica divided from the thoracic part by deep impressions, forming an acute angle. a1. Spiral of male palp having about ten convolutions. A double apophysis on anterior end of tibial jo in t ............ ........................................................Delena Walck. (7) a2. Spiral of male palp with only one convolution. Apophysis at anterior end of tibial joint single only.................................................................................. jEodelena, nov. gen. (6) |