342 THE VOYAGE OF H.M.S. CHALLENGER. 



Station 289, October 23, 1875 ; lat. 39° 41' B., long. 131° 23' W.; South Pacific 

 Ocean ; depth, 2550 fathoms ; bottom, red clay ; bottom temperature, 34°-8. Trawled. 

 Length (male), 25 mm. (1 in.). 



The rostral crest is not greatly elevated, and is furnished with only one tooth on the 

 upper margin, and behind it a very minute point. The animal offers no peculiar 

 characters, except that there is a regular fringe of fine hairs on the infero-lateral margin 

 of the sixth somite, and a slight indication of a dorsal carina ; the telson in relation to 

 the length of the other tail appendages is rather short, and the extremity is somewhat 

 truncated and flanked by two small points or denticles. 



The ophthalmopod is longer than the rostrum, flattened, and slightly curved ; it is 

 furnished near the base with a very prominent tooth-like process ; the small tubercle 

 common to the species of Benthesicymus being here largely developed. The ophthalmus, 

 at the extremity of the ophthalmopod, is orbicular, not of greater diameter than the stalk, 

 and of a brown colour, with a small mass of black pigment at the base. 



The first pair of antenna? has the peduncle long. The first joint extends considerably 

 beyond the rostrum and is hollowed on the upper surface to receive the ophthalmopod, 

 the floor of the depression being paved with minute spinules ; it is robust on the inner 

 side, lobed anteriorly on the upper surface and very thin on the outer side, where it is 

 armed with a short stout stylocerite. The second joint is short and lobed on the upper 

 surface ; the third is longer than the second, and articulates with it at the inferior angle, 

 and is lobed on the upper surface posteriorly ; it carries two flagella, of which the upper 

 is broad at the base, and supports a closely-packed series of very long, slender, mem- 

 branous cilia, and suddenly narrows to a slender filamentous termination. The lower is 

 continuously slender from the base. 



The second pair of antennae has a slender flagellum, rather longer than the animal, 

 and supports a scaphocerite that is longer than the peduncle of the first pair and 

 terminates in an ovate extremity, and the margin is fringed with numerous multi- 

 articulate ciliated hairs and is without an outer subapical tooth. 



The mandible supports a large two-jointed synaphipod, the extremity of which 

 reaches beyond the distal extremity of the peduncle of the second pair of antennae ; the 

 first joint is broad and foliaceous, the second narrow and foliaceous. 



The second pair of gnathopoda is long, has the meros and ischium long and broad, 

 the carpos long, narrow, and subequal to the propodos, and terminates in a broad, flat, 

 palm-like dactylos. 



The first pair of pereiopoda is short, robust, and terminates in a short robust chela. 

 The second pair is long and slender. The third is still longer and more slender, but is 

 lost in the typical male specimen (but preserved in the female from another station). 

 The penultimate pair is long, slender, and styliform. The posterior pair is wanting in 



