260 



feeble structure of the posterior gnatliopoda, in whicli latter respect, it agrees 

 more closely with 3£. longicorms. 



Occurrence. — It is only quite recently that I have been aware of 

 this new species, some few specimens of which were found mingled with 

 M. pusiUa from the west coast of Norway. The exact locality where the 

 specimens in reality occurred, I am, however, at present unable to state. 



17. Metopa affinis, Boeck. 



(PL 91, flg. 2). 

 Metopa affinis, Boeck, Crust, amphip. bor. & arctica, ji. 62. 

 ? SjTi: Metopa latiniaiui, Hansen. 



Body (in male) rather slender, and not very much compressed. Cepha- 

 lon not nearly twice as long as the 1st segment of mesosome, lateral cor- 

 ners rounded at the tip. Coxal plates smaller than usual; 2nd pair oblong 

 oval in form, with the anterior edge but slightly curved and the tip blunted; 

 4th pair rather oblique, much broader than they are deep, distal edge 

 nearly straight. Last pair of epimeral plates of metasome but very slightly 

 produced at the lateral corners, and nearly rectangular. Eye.s small, rounded. 

 Antennae rather unequal, the superior ones very much elongated, 1st joint 

 of the peduncle exceeding in length the cephalon, 2nd a little shorter, 

 flagellum nearly twice as long as the peduncle, and less slender than in 

 most otLer species. Inferior antennae much shorter than the superior, the 

 2 outer joints of the peduncle nearly equal-sized, flagellum attaining the 

 length of those joints combined, Anterior gnathopoda rather strong and of 

 somewhat unusual shape, raeral joint forming inferiorly a rather broad 

 setiferous dilatation, carpus nearly as long as the basal joint, and somewliat 

 subfusiform in outline, propodos a little shorter and much narrower, nearly 

 linear in form, dactylus unusuall}'' short and stout, setous on the inner edge. 

 Posterior gnathopoda very powerfully developed, carpus considerably dilated 

 and projecting at the end inferiorly as a rather large setiferous lobe, propodos 

 very large and broad, subquadrate in form, though somewhat widening 

 distally, palm nearly transverse, and shorter than the hind margin, from 

 which it is defined by a distinct though small dentiform projection, its 

 edge smooth and very slightly curved. Pereiopoda unusually strongly built, 

 and of considerable size, propodos in all of tliem very powerful and some- 

 what curved, dactylus strong and falciformly curved ; last pair with the 

 basal joint comparatively small, and oval quadrangular in form, meral joint 

 strongly dilated, with the posterior edge arched and the infero-posteal corner 



