REPORT ON THE ISOPODA. 51 



same genus and species has been met with since, not only off the coasts of Norway, but 

 also in the Arctic Ocean, by many of the exploring expeditions which have investigated 

 the marine fauna of the extreme north ; the species was obtained during the voyage of 

 the "William Barents" in great abundance, and it has been figured by Dr. Max Weber 

 in his account of the Isopoda obtained during that voyage. Dr. Oscar Harger ' has 

 recorded Munnopsis typica from the shores of North America. Three distinct species 

 of Munnopsids, obtained during the voyage of the Challenger, I refer to this genus ; two 

 species were obtained from the southern hemisphere and from very deep water; 

 Munnopsis australis was dredged at Station 146, off Prince Edward's Island, and Munnopsis 

 gracilis considerably further to the east, off the shores of New Zealand, in 1100 fathoms. 

 The third species comes from the northern hemisphere, near to Japan, in 345 fathoms of 

 water ; but I am more doubtful about assigning it to this genus. The definition of the 

 genus Munnop>sis is given below ; I have altered it from Sars's original definition so as to 

 include the two species described in the present Eeport. 



Anterior division of the body dilated, posterior suddenly much narrower and linear. 

 Four anterior thoracic segments excavated above, obtusely rounded at the sides ; the 

 three following subcylindrical, with short acuminate lateral processes. Abdominal 

 segment elongate, much longer than broad. Antennules with the basal joint large and 

 flattened, the flageUum elongate and multiarticulate ; antennse very long and slender, 

 many times longer than the body ; the two last peduncular segments greatly elongated ; 

 the flageUum about equal in length to the peduncle ; mandibles subtriangular, entire and 

 acuminate at the apex, without a molar process ; the palp absent or if present slender ; 

 its last joint thick at the base and curved in the form of a hook ; of the first four pairs 

 of thoracic limbs the first pair are short ; the second pair not much longer, rather robust 

 and subprehensile in the males ; the two following pairs greatly elongated and very- 

 slender, many times longer than the body, but with the basis, ischium and meros very 

 short ; last three pairs of legs natatory, all alike, with the last two segments foliaceous, 

 margined with long slender delicately plumose seta? ; abdominal operculum large, nearly 

 covering the whole under surface of the abdomen ; suboval, simple in the female, but 

 consisting of three distinct segments in the male, one median and very slender, and two 

 lateral, and furnished within with a peculiar curved organ, terminating behind in a 

 much elongated seta (as in Eurycope) ; caudal appendages slender, simple. 



Munnopsis gracilis, F. E. Becldard (PI. XIV. figs. 9, 10). 



Munnopsis gracilis, F. E. Beddard, Proc. Zool. Soc. Lond., 1885, pt. iv. p. 916. 

 Off the North Island of New Zealand, at Station 168, from a depth of 1100 fathoms, 

 a small Munnopsis was dredged among a very large number of specimens of Eurycope 

 novse zelandias. 



1 Marine Isopoda of New England, loc. tit., p. 329. 



