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

CRUSTACEA. 319notches, but the posterior and lateral margins of the third segmentof the postabdomen are armed with a series of small spinules whichdo not extend over the dorsal surface, but reach downward to thepostero-lateral angles ; there are also one or two small spinules orteeth at and near the postero-lateral angles of the first and secondpostabdominal segments ; the eyes are much narrower and (transversely)longer than in M. suensis, the first peduncular joint of theinferior antennae is somewhat longer and slenderer ; the wrist andpalm of the first legs (gnathopoda) are much more hairy ; the spineon the posterior surface of the merus-joint of the second legs ismuch shorter, the wrist longer, and the palm perhaps rather moreslender and hairy, with a less distinctly defined distal notch, behindas well as in front of which are one or two small teeth ; the threeposterior legs are slenderer, with the distal angles of the merusjointsacute but not prolonged into spines ; the rami of the posterioruropoda are subequal, but much longer than in Megamcera suensisand less acute. Colour (in spirit) light yellowish brown. Lengthabout 5 lines (11 millim.).A single specimen was obtained at Albany Island, 4-5 fms., withthe preceding species ; also two from Prince of Wales Channel,7-9 fms. ; and one from Thursday Island, 4-5 fms. (No. 165).In the long rami of the posterior uropoda this sjiecies somewhatresembles 31. mastersii, Haswell, from Port Jackson ; from which,however, it is distinguished by the larger narrow eyes and thesomewhat excavated and less distinctly toothed distal margins ofthe palms of the second legs ; nor does Mr. Haswell mention thespinules of the third postabdominal segment, &c.From Mcera rubromacuktta, Stimpson, it is distinguished by theentire non-pectinated postero-dorsal margins of the postabdominalsegments, the narrow eyes, and the non-defined distal margin of thepalms of the second legs.It is also apparently very nearly allied to the British Megamcerasemiserratu and M. hrevicaudata, Spence Bate, and may be only avariety of one of these species ; but in M. semiserrata the eyes arerepresented as less narrow and elongated, and the dactyli of the legsof the second pair are serrated upon the inner distal half, and inM. brevicaudata the palm has the inferior margin loss distinctlydefined and more convex in its distal portion *.I may note, in conclusion, that Kossmann has described f twospecies, Mcera erythra-a and M. massavensis, from the Red Sea,which appear to be distinguished from all the foregoing species ofMcera and Megamcera by the form of the palms of the second legs.9. Podocerus australis, Haswell.Five male specimens were obtained at Port Jackson from weedon the ship's bottom.* M. semiserrafa is one of several Anipbipoda which it would seem are inaccurately marked in Mr. Spence Bate's Catalogue as represented in tlie Museum.t Zool. Ergebn. einer Reise im roth. Meeres, pp. 132, 133, pi. xirfigs. 1-11 (1880).