CRUSTACEA OP THE MEEGTJI AECHIPELAGO. 65 



I am comparing, whicli is scarcely more than 11 millim 

 broad. 



P» Mrsuttos, Stimps.jfrom tlie Corean seas, differs fromP. ^^- 

 dersoni by the larger hand being only granulated on its upper 

 margin, and not at all on its outer surface. (See Miers, Proc. 

 Zool. Soc. 1879, p. 31.) 



Hilgeudorf's P. longicornis, from the coast of Mozambique, 

 may be easily distinguished from P. Andersoni by its antero- 

 lateral teeth, which are not spinif orm. Pilumnus JBleeheri, Miers, 

 from New Gruinea, presents a spiniform extraorbital angle and a 

 distinct subhepatic spine. 



Pilumnus terrce-regincd, Hasw., from Queensland, presents a 

 patch of small granulations on the mesobranchial regions (which 

 in P. Andersoni are smooth), the granules on the larger hand are 

 rounded, and it has a row of obscure granules on the lower border 

 of the merus and hand of the smaller chelipede. 



The upper surface of the cephalothorax of P. vesfitus, Hasw., 

 also from the eastern coast of Australia, is described as pre- 

 senting no distinct granules, whereas in this species the upper 

 surface is distinctly granulate anteriorly, as already mentioned. 

 P. vestitus, however, appears closely allied to P. Andersoni, and 

 a more exact knowledge of it is desirable, 



42. PiLUMKUs SEMiNUDUS, Miers. 



Pilumnus seminudus, Miers, Crustacea of the Voyage of H.M.S. 

 'Alert,' 1884, p. 222, pi. xxi. fig. c. 



A young female crab found at Owen Island I believe to belong 

 to the above-named species. 



The cephalothorax is rather enlarged, the proportion of the 

 breadth to the length being about as 7 to 5. The upper sur- 

 face, which is a little convex longitudinally and somewhat decli- 

 vous towards the lateral margins, presents no trace of divisional 

 inter-regional grooves, and is everywhere clothed with a close 

 velvety pubescence. I only observe a very faintly indicated 

 mesial longitudinal furrow. The front is nearly straight and 

 presents a small median incision ; the two lobes into which the 

 front is thus divided are not separated by a notch from the 

 internal orbital angles, so that the latter constitute at the same 

 time the external angles of the front. The orbital margins are 

 minutely denticulate, though the denticulation of the upper 

 margin is scarcely visible ; the internal angle of the lower border 



LTNN. JOURN. — ZOOLOGY, VOL. XXII. 5 



