630 



THE VOYAGE OF H.M.S. CHALLENGER. 



species was taken near the south part of Japan, and a smooth or less dentated form off 

 Manila in the Philippine Sea. 



The depth at which the oriental specimens were taken ranged from 250 to 700 

 fathoms, while those from the West Indies were got in 218 and 955 fathoms respectively. 



Heterocarpus dorscdis, n. sp. (PI. CXI.). 



Eesembles Heterocarpus oryx, A. Milne-Edwards, but may be distinguished from it 

 by having only eight teeth on the dorsal crest and upper margin of the rostrum and 

 seven on the lower, by the first pair of antennae being longer than the rostrum, and the 

 second pair twice the length of the animal. 



Habitat.— Station 194, September 29, 1874; lat. 4° 34' 0" S., long. 129° 57' 30" E. ; 

 off Banda Island ; depth, 200 fathoms; bottom, volcanic mud. Two specimens; females. 

 Dredged. 



The carapace is traversed longitudinally by five distinct carinse, of which the central 

 is anteriorly produced to a rostrum that is half as long again as the carapace, and is 

 armed with eight well-defined teeth, the posterior being on the gastric region ; the 

 lower margin of the rostrum is furnished with seven strong teeth, of which the posterior 

 is considerably in advance of the orbital margin. 



The second or upper lateral carina commences at the orbital margin just above the 

 tooth of the outer canthus, and passes a little outwards and downwards along the surface 

 of the carapace to within a short distance of the posterior margin, at which point it is 

 deflected at right angles inwards towards the median carina, posterior to which it meets 

 the corresponding bend of the carina on the opposite side. The lower lateral carina 

 commences at the fronto-lateral angle of the carapace, which is anteriorly produced to a 

 long strong tooth, and traverses the carapace in a line parallel with the preceding ridge, 

 and terminates gradually, being lost at a short distance from the posterior margin. The 

 infero-lateral margin of the carapace is also traversed by a stout ridge that commences 

 on the inner side of the fronto-lateral tooth, and is continuous to the posterior margin. 

 There is moreover a small carina between this marginal ridge and the lower lateral ; it is 

 very short, commencing at the posterior edge of the carapace and disappearing at a 

 point which corresponds with the coxa of the posterior pair of pereiopoda. 



