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

222 COLLECTIONS FROM MELANESIA.57. Pilumnus semilanatus. (Plate XXII. fig. B.)The carapace is not very convex ; a few granules exist near theantero-lateral teeth ; its anterior part (i. e. the frontal and postfrontalregions and parts adjacent to the antero-lateral margins) isclothed with longish hairs, which are altogether absent from thegastric, cardiac, and branchial regions, which are nearly plain andsmooth ; the cervical suture only is distinct in some specimens ;the frontal lobes are scarcely defined by a median notch, and arevery little prominent ; the antero-lateral margins much shorterthan the postero-lateral, and armed with three teeth, the first ofwhich is blunt and is itself crenulated, the second dentiform, andthe third very small ; no tooth exists at the exterior angle of theorbit, but immediately behind it are sometimes one or two smallgranules ; the orbital margins are rather obscurely denticulated ;the pterygostomian regions nearly smooth ; all the postabdominalsegments are distinct ; the basal antennal joint barely reaches tothe subfrontal process ; the merus-joint of the outer maxiliipedes isnearly quadrate. The chelipedes are of moderate size ; arm with asmall spine near the distal end of its upper margin; wrist granulatedexternally, the granules inconspicuous, and with a small spineon its inner margin ;palm also granulated above and externally, thegranules large and showing a tendency to disposition in longitudinalseries, and becoming more crowded toward the lower margin ; fingersbrownish, the coloration not extending over the palm : legs slenderand proportionately rather long. Length of the largest perfectspecimen rather over 4 lines (9 millim.), breadth 5 lines (nearly11 millim.).Three small specimens (a male and two females) are in thefirst collection, but unfortunately without definite locality ; the labelwith particulars respecting habitat (if there existed any) was lostwhen the bottle (No. 123) came into my hands. In the secondcollection two males from Prince of Wales Channel, 7-9 fms.Either the left or the right hand may be the larger.There are in the collection of the British Museum a male and afemale specimen preserved dry, and collected by Mr. J, Macgillivrav(H.M.S. ' Rattlesnake ') off" Cape Capricorn, in 15 fathoms, on a muddy,sandy, and shelly bottom, that I refer to this species ; also an adultmale from Moreton Bay (piirchased). The coloration of Dr. Coppinger'sspirit-specimens is ])urplish, that of the dry examples reddishbrown.This species bears some slight resemblance to P. monilifera, Haswell,from Tasmania (vide Cat. p. 65, pi. i. fig. 3), which, however,has the carapace and limbs covered with a short close pubescence,and the front much more deeply incised, the carapace more granulated.58. Pilumnus semimidus. (Plate XXI. fig. C.)This species resembles the foregoing in having the gastric, cardiac,and branchial regions of the carapace smooth and naked ; but it may