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

190 COLLECIIONS FROM MELANESIA.4. Oncinopus aranea.De Haan, Faun. Jajjon., Crust, p. 100, pi. xxix. fig. 2 (d ?), andpi. H (1839).Oncinopus neptuniis, Adams Sj- White, Zool. Samarang,^ ^ Crust, p. 1,pi. ii. fig. 1 (1848).Oncinopus subpellucidus, Stimpson, Proc. Ac. Nat. Sci. Pkilad. p. 221(1857) ; Haswell, Cat. Austrcdian Stalk- and Sessile-eyed Crust, p. 5(1882).Oncinopus angulatus, Haswell, Proc. Litm. Soc, N. S. Wales, iv.p. 43.3 (1880).Specimens are in the collection from Port Jackson, 5-7 fms.(No. 104), and Port Molle, 14 fms. (No. 93). Besides the abovespecimens the British-Museum series includes examples from PortJackson (J. Brazier cf-c), from Brisbane Water, Queensland (Macgillivray,H.M.S. ' Rattlesnake '), from the Mindoro Sea {A. Adams,H.M.S. ' Samarang '), and from the New Hebrides (J.Macr/iUivraif).Oncinoi)us subpellucidus, Stimpson, from Port Jackson, only differs(according to its author) from 0. neptunus in the somewhat smallerand slenderer terminal and penultimate joints of the posterior legs,and can scarcely be regarded as distinct, Onciuojnis nraneus ofDe Haan (the species on which the genus was originally founded)was regarded by Adams and White as distinct from 0. neptunus, onaccount of the much shorter legs, more deeply-incised front, withmore angulated lobes ; but there is an adult specimen from PortJackson, in Dr. Coppinger's collection, in which the legs are onlytwice as long as the carapace, and quite as robust as in De Haan'sfigure of 0. araneus ; and in a male from Brisbane Water, (Queensland,in the Museum collection, the chelipedes have their palmsdilated, just as in the Japanese species. In consideration of theevident variability of the length and robustness of the legs in thisgenus, I have considered it necessary to unite all the describedspecies under De Haan's original designation, 0. araneus.5. Mensethius monoceros (Latr.).A male is in the collection from Port Denison, (Queensland, 4 fms.(No. 111). I have in a previous Peport* remarked upon the widedistribution of this common Oriental species, and for the numeroussynonyma would refer to A. Milne-Edwards's report on the Crustaceaof New Caledonia f.A female received in Dr. Coppinger's second collection from Princeof Wales Channel (No. KiO) differs widely in its broader, much morestrongly tuberculated carapace from the male from Port Denison ;in these particulars it closely resembles specimens from the Mauritiusin the British-Museum collection. Specimens from Shark Bay, WestAustralia {Surgeon Rayner, H.M.S. Herald ' ') nearly approach theMauritius specimens in these particulars.* Philosoph. Trans. Eoy. Soe. clxviii. p. 485 (1879).t Vide Nouv. Arcliiv. Mus. Hist. Nat. viii. p. 252 (1872).