258 

 15. Metopa longicornis, Boeck. 



(PL 90, fig. 2). 

 Metopa longicornis, Boeck, Crust, ainphip. bor. & arctica. p. 63. 



Body somewhat resembling that of the preceding species, though 

 being perhaps a little more slender, and having the metasome more fully 

 developed. Cephalon twice as long as the 1st segment of mesosome, lateral 

 corners somewhat produced but blunted at the tip. Coxal plates rather deep, 

 and nearly of same form as in M. pusilla. Last pair of epimeral plates of 

 metasome somewhat more produced at the lateral corners, though not forming 

 any sharp angle. Eyes of moderate size, rounded. Antennae rather elongated, 

 the superior ones exceeding half the length of the body, 1st joint of the 

 peduncle somewhat longer than the cephalon, 2nd joint about the same 

 length, flagellum scarcely longer than the peduncle, and composed of about 

 20 articulations. Inferior antennae about the length of the superior, last 

 joint of the peduncle a little shorter than the penultimate one, flagellum 

 about of same length as the former. Anterior gnathopoda of moderate size, 

 propodos fully as long as the carpus, and slightly dilated in the middle, 

 its inferior edge having in addition to the setae a row of about 7 minute 

 spinules. Posterior gnathopoda comparatively feeble in structure, and 

 scarcely longer than the anterior, propodos oblong triangular, and much nar- 

 rower than in M. pus ill a, palm rather oblique and nearly as long as the 

 hind margin, from which it is defined by a small dentiform projection, its 

 edge quite smooth, having only a few fine hairs. Pereiopoda comparatively 

 less strong than in the said species, especially the 3 posterior pairs, in each 

 of which the meral joint is rather narrow, sublinear in form, and but very 

 slightly produced at the infero-posteal corner; last pair with the basal joint 

 exceeding half the length of the remaining part of the leg, and somewhat 

 irregularly oval in form, its posterior edge being abruptly curved in the 

 middle. Last pair of uropoda with the basal joint nearly as long as the 

 other 2 combined, and armed with 3 rather strong denticles. Telson oblong 

 in form, fully twice as long as it is broad, and armed with 3 pairs of strong- 

 dorsal denticles, tip blunted. Colour in the living state of the animal, not 

 yet stated. Length of adult female 4 mm. 



Remarks. - - The present species, established by Boeck, would seem to be 

 most nearly allied to M. pusilla, from which it is however easily distinguishable 

 by the still more elongated antennae, the much larger eyes, the feeble struc- 

 ture of the posterior gnathopoda, and the narrow linear form of the meral 

 joint in all the pereiopoda. It moreover attains a much larger size than 

 the said species. 



Occurrence. I have not myself met with this species, but Boeck 



