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

;194 COLLECTIOKS FROM MELANESIA,at the distal end of eacti basal antennal joint two teeth, whereof oneis directed downward and one outward. The legs are more or lesspubescent. The chelipedes are slender ; the atm or merus-jointdenticulated on its lower surface, and armed above with three orfour short spines ; the wrist or carpus rather obscurely bicarinatedhand (in both sexes) smooth, slender, naked, somewhat compressed,and twice as long as broad, or even longer ; fingers straight andacute. The ambulatory legs are of moderate length ; the merusjointsusually bear two well-developed distal spines, but one of theseis occasionally absent ; there is usually a short spine or tubercle atthe distal end of the following joint, which is most distinct in thefirst pair of ambulatory legs ; dactyli slightly curved. Length ofthe largest specimen (an adult female) to base of rostrum about 1-^inch (30 mm.), of rostral spines -^tj inch (15 mm.), greatest breadthrather over -| inch (22 mm.) ; length of first ambulatory leg about1| inch (38 mm.).There are in the first collection several specimens of both sexesfrom Port Curtis, 7-11 fms. (Nos. 85, 87). In the second collectionare two males from Thursday Island, 3-4 fms. (No. 175).The spines of the dorsal surface of the carapace vary considerablyin length.Several of the specimens are more or less thickly covered with anovergrowth of Polyzoa and Sertularians {Thuiaria and Grisia), andwith a species of Zoanthus.From P. aculeatiis, as described by Milne-Edwards, this varietyis distinguished only by the form of the postocular spine (see fig. A),and by the existence (usually) of two spines at the distal end ofthe merus-joints of the ambulatory legs. From the P. halimoides,recently described by me, it is distinguished by having two spineson each branchial region, the form of the postocular tooth, &c.Several other species of this subgenus have been described, noneof which, are to be confounded with P. (Chlorinoides) aculeatus.P. S2yatiilife>\ Haswell, a species dredged at Port Stephen, is atonce distinguished by its bifurcated rostral spines, &c.11. Hyastenus diacanthus {De Ilaan).A male and three females of this very common species are retainedfor the collection from Thursday Island, Torres Straits, 3-6 fms.(Nos. 130, 175), one was received from Port Denison, another fromPort Molle, 14 fms. (93), another from Port Curtis, 0-11 fms.(92), and another from Port Darwin (12 fms.). As is very usualwith H. diaca7ithus, these specimens are more or less covered•with sponges, &c.I have already referred to the synonyma and general distributionof this species *.In a very small female in the collection, from Port Denison,* Proc. Zool. Soc. pp. 19, 26 (1879) ; Cat. New-Zeal. Crust, p. 9 (1876).