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

;CRUSTACEA. 5214, Menaetliius monoceros (Latr.).A scries of specimens of both sexes and various ages are in thecollection from the Seychelles, 4-12 fms. (No. 194) ; also a smallfemale obtained on the beach at Mozambique (No. 224), which hasthe prominences or lobes of the antero-lateral margins spiniformand acute.I have already referred to this widely distributed and variablespecies on p. lUO.A small female specimen, which has unfortunately lost all thelegs, obtained at African or Eagle Islands, 10 fms. (No. 184), hasthe rostrum remarkably abbreviated, not equalling in length theinterocular width of the frontal region ofthe carapace, the greatestwidth at the branchial regions little exceeding the width at thefrontal region, and the basal antennal joint more dilated than in thetypical M. monoceros. It appears to merit distinction at least as avariety, since I have seen no specimen in the extensive Museumseries which closely resembles it, but I refrain for the present fromdesignating it as such.5. Stilbognathus martensii. (Plate XLVI. fig. B.)I propose thus to designate two males obtained at Marie-LouiseIsland, 17 fms. (No. 180), and a male from Providence Island, li)fms. (No. 217), which, although having the ischium-joint of theouter maxillipcdes longitudinally sulcated (and hence certainlybelonging to iStilbofjiiatJivs), differ from Stilhoynatlius erythraus, VonMartens*, from the Ued Sea, in the form of the merus-joint, whichhas its extero-distal angle produced and acute as in Stenocionopscervicornis, and which further differs from the known species bothof Stenocionops and iStilbogjutthus in having the notch on the innermargin (where the fourth joint articulates with it) provided with atooth or lobe (see fig. h).The carapace is constricted behind the orbits (as in S. cerviconiis) ;the gastric, cardiac, and front of the branchial regions are ratherconvex and more or less distinctly covered with small tubercles orgranules ; the posterior margin of the carapace is cristate and prolongedin the median line into, a tooth or lobe. The spines of therostrum are slender and curved at first outwards and then inwardsso as to meet at the apices, which are vertically refiexed as in IStenocionopscicrvirostm, A. M. -Edwards. There is a rounded prominenceupon each pterygostomian region. The supraocular spines of thecarapace are very long and straight ; the eye-peduncles even longerthe basal antennal joint is considerably dilated, and has a smallspine on its outer side near the base and another at its distal extremity.The longitudinal pit on the outer surface of the ischiumjointof the outer maxillipcdes is longer than in Stilhoynatlais erij-* Verbandl. zool.-bot. Gcscllsch. Wieu, xvi. p. 370, \. (1866).