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

CRUSTACEA. 221lower surfaces of the hands ; the front is moderately defiexed, and isdivided by a median notch into two rounded lobes ; the autero-lateralmargins are somewhat shorter than the postero-lateral, with onlythe three posterior teeth distinct, these are small and spiniforra.The orbits are tuberculated on their margins, but without any distinctspinules ; the inner suborbital angle is rather prominent. Allthe postabdominal segments are distinct in both sexes. The basalantennal joint apparently does not reach to the front ; the merusjointof the outer maxillipedes is short and transverse ; the chelipedesin the male have the merus-joint short and trigonous, with atooth near the distal end of its upper margin ; carpus and palmgranulated on their outer surface, but the granules for the mostpart concealed by the pubescence ; there is a small tuberculiform orsubspiniform tooth on the inner margin of the carpus or wrist ; thehand (for so small a species) is large, its inner surface naked, smooth,and polished, and the granulations usually obsolete on the nakedpart of the outer surface in the larger chelipede ; the fingers arechocolate-brown, the coloration not extending over any part of thepalm, and the upper finger has scarcely any traces of teeth on itsinner margin. The ambulatory legs are closely pubescent. Lengthof the largest male in the collection a little over 4g lines (10 millim.),breadth about 6| lines (14 millim.) ; length of largest chelipedeabout 10| lines (22 millim.).Ten specimens are in the collection, from Port Jackson, 5-7 fms.(No. 104).Either the right or the left chelipede may be the larger in themale. Occasionally the granulations of the hands are distinct evenupon the naked part of the outer surface ; there are several femalesin the series of very small size, yet bearing ova.There is in the British-Museum collection a specimen from PercyIsland (H.j\I.S. Herald ' '). Possibly also a small male from Tasmania(B. Giinn) is to be referred here.Finally, there are in Dr. Coppinger's collection a series of verysmall specimens from Port Denison, 4 fms. (No. Ill), of muchpaler colour than those collected at Port Jackson, and two fromPort Curtis, 11 fms. (No. 87), which j)erhaps belong to this species.This species bears some resemblance to P. hirsutus, Stimpson,which Mr. Haswell records from Port Jacksoi], but differs (in theadult at least) in the close brown pubescence, and in having a series oftubercles or small spines on the carpus (not merus) of the ambulatorylegs. In the specimens from the Japanese or Corean seas referredbut a single spinuleto P. hirsvtus in the Museum collection there isat the distal end of the carpus of these legs. Pilumnus Jisdfrons,Stimpson, from Port Jackson, differs in having the carapacedistinctly areolated and the antero-lateral marginal teeth normallydeveloped.If our specimens should prove to belong to an undescribed species,I would propose for tliem the name of P. humilis.