812 



THE VOYAGE OF H.M.S. CHALLENGER. 



pleopoda, which in the smaller specimen is short, broad, and foliaceous, is in the larger 

 narrow, thick, and lanceolate in form, and about two-thirds the length of the outer branch, 

 assuming much the condition of the same part in the female. 



From the imperfect condition of the specimens at my command, I have not been able 

 to make a full comparison, but I am inclined to think that the smaller variety is the 

 more active form of the male animal, whereas the larger variety is one of those older 

 specimens that are becoming effete, and putting on certain appearances which are more 

 generally conspicuous in the females. 



A solitary much-damaged female specimen, laden with numerous small ova, was trawled 

 halfway between the Fiji Islands and the New Hebrides at a depth of about a mile and 

 a half from the surface, which I consider as belonging to this same species. Half of the 

 rostrum is broken off, and all the appendages are gone, but the armature of the frontal 

 crest, and the projection to an obtuse point of the posterior dorsal margin of the third 

 somite of the pleon, show its near relationship to the present species. 



Nematocarcinus tenuipes, n. sp. (PI. CXXXII. fig. 6). 



Carapace anteriorly produced to a rostrum that is slightly elevated from the base to 

 the apex, and armed on the upper surface with two and twenty small spinules and teeth, 

 and upon the lower surface with one tooth near the extremity. 



Pereiopoda long and slender, and terminating in a dactylos that is as long as the 

 propodos. 



Telson longer than the inner, and shorter than the outer, plates of the rhipidura. 



Habitat.— Station 235, June 4, 1875 ; lat. 34° 7' N., long. 138° 0' E.; south of 

 Japan; depth, 565 fathoms; bottom, green mud; bottom temperature, 38°'l. Six 

 specimens ; four males, two females. Trawled. 



Station 218, March 1, 1875; lat. 2° 33' S., long. 144° 4' E.; near the Admiralty 

 Islands; depth, 1070 fathoms; bottom, blue mud; bottom temperature, 36°"4. One 

 specimen (damaged), male. Associated with Polycheles helleri. Trawled. 



Station 232, May 12, 1875 ; lat. 35° 11' N., long. 139° 28' E; Hyalo7iema-ground, 

 Japan ; depth, 345 fathoms ; bottom, green mud ; bottom temperature, 41°'l. Six 

 specimens ; three males, three females. Trawl and dredge both used. 



