84 



duced below the emargination to a sharp corner; 5th pair rather large, much 

 more broad than deep, and exhibiting on the middle a very conspicuous trans- 

 versal umboniform eminence. Last pair of epimeral plates of metasome not 

 produced at the infero-lateral corners and nearly rectangular. First segment 

 of urosome without any dorsal projection, but slightly impressed at the base. 

 Eyes inconspicuous in spirit-specimens. Superior antennae about the length of 

 the 5 anterior segments of mesosome combined; 1st joint of the peduncle elon- 

 gated, more than twice as long as the other 2 combined and of uniform breadth 

 throughout; flagellum of rather coarse structure, about twice the length of 

 the peduncle and composed af about 25 joints, the 1st of which is by far the 

 largest; accessory appendage scarcely l /z as long as the flagellum, very narrow, 

 almost setiform, and composed of 6 articulations subequal in size. Inferior an- 

 tennae a little longer than the superior, last joint of the peduncle longer than the 

 preceding one, flagellum more slender than that of the superior and composed of 

 about 23 articulations. Anterior gnathopoda with thepropodos about twice as long 

 as the carpus, oblong oval, palmar edge very oblique and scarcely defined below, 

 dactylus about half the length of the propodos. Posterior gnathopoda with the pro- 

 podos a little broader than the carpus and about half its length. Basal joint of the 

 last pair of pereiopoda broadly oval, more than twice as large as that of the ante- 

 penultimate pair. Last pair of uropoda with the inner ramus a little shorter than 

 the outer, terminal joint of the latter rather small. Telson fully twice as long 

 as broad at the base, gradually tapering, with 2 pairs of dorsal denticles, 

 cleft extending far beyond the middle, very narrow, fissure-like. Colour whit- 

 ish. Length of the only specimen procured 11 mm. 



Remarl'S. I have been in some doubt about the sex of the specimen 

 examined and, having not found any distinct incubatory lamellae, have signed 

 it on the plate as a male, thus believing the calceolae of the antennas to be 

 a peculiar masculine character. The Rev. Mr. Stebbing has, however, on the 

 plate representing his species Trypliosa antennipotens determined the specimen 

 as a female, though it has the antennae provided with calceolae in exactly 

 the same manner as the Norwegian specimen. It would thus appear that in 

 this genus, as is the case with Ichnopus, both sexes are provided with those 

 peculiar appendages. From the Challenger species the present form is easily 

 recognized, not only by the peculiar umboniform eminence of the 5th pair of 

 coxal plates, but also by the absolute want of any dorsal projection of the 1st 

 segment of the urosome. 



Occurrence. - The above described specimen was collected many years 

 ago at Hvitingso, west coast of Norway, from a depth of about 150 fathoms. 



Distribution. Skagerak (Gunhilds Expedition), 1 specimen collected 

 at a depth of 400 to 420 fathoms. 



