422 Prof. J. Wood-Mason on a new 5/?eci'e5 o/" Portunidae. 



XLII. — Description of a new Species of Portunida^ f)-om 

 the Bay of Bengal. By Prof. J . Wood-Mason, Deputy 

 Superintendent of the Indian Museum, Calcutta. 



Goniosoma Jioplites^ n. sp. 



The wliole animal is covered witli a short and dense pubes- 

 cence, which is developed into cilia on the edges of the legs 

 and between the cpibranchial teeth. The carapace resembles 

 that oi Neptunus gladiator in the distribution of its granulated 

 lines and elevations. The an tero- lateral margins are armed 

 Avith six teeth ; the first two small, similar, close together, and 

 rather obtuse ; the third and fourth larger, sharper, curved a 

 little forwards, and broad-triangular ; the fifth rather smaller 

 than these, but similarly sha]:)ed ; the last very sharp and 

 long, about thrice the length of any of the rest. Front 

 divided into eight teeth arranged in pairs ; or into four bilobed 

 ones, each lateral tooth being subdivided into two nearly equal 

 and similar lobes, the outer one of which forms the inti-a- 

 orbital angle, each median tooth into two unequal and dissimi- 

 lar ones, the external and smaller of which is directed slightly 

 outwards and has its extremity rounded off, but the internal 

 and larger has its external angle obliquely cut away and its 

 internal angle rounded off; the two median teeth are sepa- 

 rated from one another by a fissure shallower and narrower 

 than those which divide them from the lateral ones. Poste- 

 rior angles each produced straight outwards to a strong and 

 blunt process, the posterior edge of which is in the same 

 straight line with the hinder margin of the carapace ; and the 

 emarginations for the reception of the bases of the swimming- 

 legs are in consequence much deeper than usual. Chelipedes 

 and legs agree with those of Goniosoma caUianassa, Hei'bst, 

 except that the meropodites of the former have a shai-]? spine 

 at the very extremity of their posterior crest and only two 

 spines in front, that the spine on the internal margin of the 

 carpopodites is very long and acuminate, and that the im- 

 movable finger has at the base but four transversely convex 

 ridges instead of five, the central rib to be seen on the under 

 surface of this part in G. callianassa being absent — that the 

 thighs of the walking-legs are a little thicker at base and all 

 have the lower and posterior crest produced at the apex to a 

 sharp spine, and that the penultimate joint of the swimming- 

 pair is obviously denticulated below. 



Length of the carapace 15'0 millims., breadth 28*5; breadth 

 of the hinder margin 12'5 ; length of the last epibranchial 

 spine 3"0. 



Hah. Madras. 



