591 



6. Ischyrocerus megalops, Gr. 0. Sars, n. sp. 



(PI. 210, fig. 2). 



Body not very slender, but somewhat compressed. Cephalon about 

 the length of the first 2 segments of mesosome combined, lateral lobes 

 distinctly angular. Coxal plates rather large, successively increasing to the 

 4th pair, which are considerably deeper than the corresponding segment ; 5th 

 pair only half as deep as the preceding pair. Last pair of epimeral plates 

 of metasome obtusangular. Eyes unusually large, rounded oval in form, and 

 having the visual elements very fully developed, pigment dark. Antennae 

 rather strongly built, the superior ones equalling about half the length of 

 the body, and having the last 2 peduncular joints subequal, flagellum half 

 the length of the peduncle, and composed of 8 articulations, accessory appendage 

 extremely minute, not nearly attaining to half the length of the 1st articulation 

 of the flagellum. Inferior antennae (in male) about same length as the supe- 

 rior, last joint of the peduncle a little longer than the penultimate one, 

 flagellum about the length of the former joint, and 6-articulate. Both pairs 

 of gnathopoda in male comparatively stout, and rather similar in structure, 

 though the posterior ones are much the larger; propodos rather broad and 

 oval in form, with the palm simple, without any trace of projections, being 

 defined posteriorly by a slight angle carrying several short spines. Pereio- 

 poda comparatively stout, basal joint of the antepenultimate pair of a some- 

 what unusual form, being very broad at the base, and scarcely narrower than 

 that of the 2 posterior pairs. Last pair of uropoda nearly of same structure 

 as in /. minntus. Telson triangular in form, and carrying dorsally a few 

 simple bristles, outer part tapering to an obtuse point. Body whitish, with 

 indistinct brownish bands across the segments and coxal plates. Length of 

 adult male 7 mm. 



Remarks. - - The present new species exhibits in the structure of the 

 gnathopoda some resemblance to the Arctic form, I. latipes Kroyer, from which, 

 however, it is easily distinguishable, especially by the unusually full deve- 

 lopment of the eyes. 



Occurrence. I have only seen a few specimens of this form; these 

 were collected at Hammerfest, being found clinging to Hydroidte at a depth 

 of about 40 fathoms. 



