846 



THE VOYAGE OF H.M.S. CHALLENGER. 



Notostomus, excepting in the relative lengths of the several joints and in having the 

 mastigobranchial plates larger in proportion. 



The second pair of gnathopoda is broken off near the mero-carpal articulation, but the 

 joints remaining are compressed and curved. 



The pereiopoda so far as preserved resemble those of Hymenodora mollis, and are 

 remarkable for the great length of the propodos, which is cylindrical, and for the flattened 

 or compressed condition of the ischium and meros. The first two pairs are chelate and 

 slender, the second being more slender than the first and having the carpos longer than 

 the propodos, and all are furnished with a well-developed basecphysis. 



The first pair of pleopoda has the inner ramus reduced to a rudimentary condition ; 

 all the others have the two branches subequal, the inner of the anterior pair carrying a 

 long, slender, and cylindrical stylamblys, the extremity of which is furnished with a 

 bundle of small cincinnuli. The posterior pair is too much damaged to be described, but 

 what remains appears to be of generic character. 



Hymenodora rostrata, n. sp. (PI. CXXXVI. fig. 4). 



Dorsal surface of the carapace laterally compressed and anteriorly produced in a 

 depressed line to a sharply pointed rostrum, that reaches as far as the distal extremity 

 of the first joint of the first pair of antennae, and furnished on the upper surface with 

 eight small denticles ; inferior margin smooth and receding oblicpiely to the orbit, which is 

 clearly defined but furnished with no tooth at the outer canthus. First and second 

 antennal teeth small ; the second is strengthened by a long carinadike ridge that proceeds 

 posteriorly from it. 



Pleon slightly carinated and produced to a small tooth on the fourth and fifth somites ; 

 on the third and sixth the carina terminates abruptly. 



Habitat— Station 184, August 29, 1874; lat. 12° 8' S., long. 145° 10' E.; near 

 Torres Strait; depth, 1400 fathoms; bottom, Globigerina ooze; bottom temperature, 

 36°. One specimen, male. Trawled. 



Station 205, November 13, 1874 ; lat. 16° 42' N.; long. 119° 22' S.; Philippine Islands ; 

 depth, 1050 fathoms; bottom, blue mud; bottom temperature, 37°. One specimen, 

 male. Trawled. 



