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

;CRUSTACEA. 559fingers ai'e acute, slightly incurved at the tips, and have their innermargins thin-edged and entire ; the three following pairs of legshave the joints smooth, naked, and rounded ; the merus-joints butlittle thickened and -without spinules ; the penultimate joints havea small mobile spinule at the distal end of their posterior margindactylus with a single small accessory spinule. The whole of theupper and lateral surface of the carapace and the legs are closelypunctulated with small circular red spots ; the ground-colour isyellowish.Length of carapace nearly 6 lines (12 millim.).A single male was obtained on the beach at Mozambique, betweentide-marks (No. 224).There is scarcely any character mentioned in M. Milne-Edwards'svery short description, based on a specimen from New Ireland,that will not apply to the specimen from Mozambique, unless it bewhat relates to the spines of the wrist.13. Petrolisthes villosus ?? Porcellana villosa, Richters, Decapoda, in Mobius's Beitrdgc zurMeeresfauna der Insel Mauritius und der Seychellen, p. IGO,pi. xvii. figs. 11, 12 (1880).A small male collected at Darros Island (No. 200) with P. lamarclciiis referred here. To Dr. liichters's short description I mayadd the following :—The median frontal lobe is prominent androunded, and more distinctly defined than in P. lamarclii, var.asiatica. There is apparently no spinule on the lateral margin ofthe carapace. There is a strong lobe or tooth at the distal end ofthe merus-joint of the chelipedes ; between the three prominentlobes or teeth of the anterior margin of the wrist are one or twosmaller teeth ; the posterior margin of the wrist is entire. Thedactyli of the first to third ambulatory legs have three small accessoryspinules. This species has been hitherto a desideratum to theMuseum collection.Several14. Polyonyx biunguiculatus (Dana).specimens from the Seychelles, 4-12 fms. (No. 194), andEtoile Island, 13 fms. (No. 191), are referred to this species, which,as I have stated in the preceding part of this Eeport (p. 271), is distinguishedfrom P. ohcsulus by the much more prominent and acutemedian lobe of the front. I may add that the specimens I haveexamined, both from the ' Alert ' collection and from the Gulf ofSuez {R. IlacAndrew), have a prominent lobe at theinner and distalangle of the merus-joint of the chelipedes, which is not representedin Dana's figure of this species, and which is scarcely or not at alldeveloped in P. obesulus. This character will perhaps be foundsufficient to distinguish these specimens from P. binuf/uicnlatus,Dana, at least as a marked variety.