Report on the zoological collections made in the Indo-Pacific Ocean ...

206 COLLECTIONS FROM MELANESIA.it differs in the character of the tuberculation of the carapace andlegs. In the smaller examples the tubercles are much smaller andmore acute, and these specimens have much the aspect of certainActcece^ e. g. A. granulata, Audouin, and^. carcharias, 'White ; fromboth of which species they may be distinguished upon the mostsuperficial examination by the smoothness of the sternum and postabdomen.A small specimen from Tasmania in the British-Museum collection,designated " X. peronii, M.-Edw.," in, I think, Prof. A.Milne-Edwards's handwriting, and two from Bass Straits, receivedwith fishes of H.M.S. Challenger ' ' collection, are intermediate betweenthis genus and Actcea, and are principally distinguished bythe smooth, more distinctly separated and rounded tubercles of thecarapace and the longer spines of the ambulatory legs. I believethe Xantho spinosus of Hess to be identical with A. peronii.Actaiodes polyacantlius* , from the Red Sea, comes very near thisspecies, but has five acute antero-latcral marginal teeth, &c.Euxanthus mamlatus, Haswellf (which is only known to me bythe author's brief diagnosis), from Darnlcy Island, differs in theform of the teeth of the antero-latcral margins and the existence oflongitudinal rows of pits on the outer surface of the hands.34, Hypoccelus pxaictatus. (Plate XIX. fig. B.)The carapace is transverse, somewhat broader in proportion to itslength than are specimens of ff. SGuIp)tus in the Museum collection.As in that species it is everywhere strongly lobulated, the lobulesrounded, convex, and separated by deep intervening grooves, thecervical suture being even wider and deeper than the rest ; the lobulesare rather coarsely punctulated. The front is rather obscurelybilobated (besides the rounded lobe over the inner orbital angle) ; theantero -lateral margins are strongly arcuated and cristiform, withscarcely any indications of any antero-lateral teeth except the last,which is small and little prominent ; the postero-lateral margins areshorter than the antero-lateral margins and dee2)ly concave. Theinferior parts of the body are more or less coarsely pitted ; thepterygostomian cavity is smaller than in B. sculptus, but ratherwider tlian in a specimen of H. granulatus in the Museum collection,nearly ovate in outline, and divided along its greatest width by acrest running parallel to that part of the antero-lateral margin thatborders the cavity above. The basal antennal joint enters the innerorbital hiatus, but not so deeply as in H. sculptus. The chelipedesresemble those of H. sculptus ; the wrist and pahn, however, arestrongly pitted on their upper and outer surfaces, whereas in specimensof B. scidptus in the Museum collection these pits are absentfrom the wrist and from the upper surface of the palm, Fingers* Chlorodius poll/acanthus, Heller, Sitz. Akad. Wien, xliii. (i.) p. 339, pi. ii.fig. 21 (1861).t Proc. Linn. Soc. N. S. Wales, vi. p. 751 (1881); and 'Catalogue,' p. 48(1882).