26 



of the length, has its most proximal part shaped as a moderately broad triangle : the spines 

 along the lateral margins are very numerous, very unequal in size but nearly regularly arranged, 

 in the large specimen two or three short spines, in a smaller specimen only a single short 

 spine, being placed in the interval between two much longer spines, but near the distal end 

 and towards the base of the spiniferous part of the margins this regularity gradually disappears, 

 as the spines near both ends are more uniform in length. 



Length of the largest specimen, a female with the marsupium half-developed, 2 i mm. 



Remarks. — This species is allied to B. arctica Kr., but in the latter form the squama 

 is much longer and narrower and the telson decreases feebly in breadth from before the middle 

 to the end. The material to hand comprises a female with the marsupium half-developed, a 

 younger female and the cephalothora.x of a scarcely adult male. But in the same bottle I found 

 the cephalothora.x of a fourth specimen which is far from adult and has a large Epicarid 

 attached to the skin between the eyes ; in this specimen the squama is shaped as in B . Sidogcr, 

 but the eyes are smaller and the eye-stalks not depressed, wherefore I cannot decide with 

 certainty whether this specimen belongs to B. Sidogcr or to another species ; I am apt to think 

 that it belongs to B. Sidogcr and may venture the hypothesis that the reduction of the eyes 

 may be due to the influence of the parasite. 



II. Boreomysis inermis n. sp. PI. II, figs. \a — \c. 



Stat. 141. August 5. Lat. \° d .^ S., long. i27°25'.3 E. 1950 m. Hensen vertical net, from 

 1500 m. depth to surface, i specimen, cf. 



Description. — Frontal plate considerably produced, with the anterior part of the 

 lateral margins very convex and then directed inwards forming a flatly convex front margin, 

 at the middle of which a small, triangular, acute rostrum is seen (fig. 4^). Eyes somewhat 

 smaller than in B . SidogcF, not fully as deep as broad, as broad as the end of the stalk, very 

 light brownish ; eye-stalks scarcely depressed, much broader than long, with the tubercle very 

 prominent. Antennal squama (fig. 4a) more than three times as long as broad, broadest somewhat 

 before the middle ; the outer margin feebly concave ; the terminal lobe very short, slightly 

 long-er than the short marginal tooth. 



Exopod of third pair of pleopods rather considerably longer than the endopod and a 

 little longer than the exopod of second pair. Exopod of uropods (fig. 4^) with the margins 

 subparallel and the outer margin setose to rather near the base, the nakeci part being unusually 

 short, considerably shorter than the breadth of the exopod, apparently without spines at the 

 end; endopod of uropods with a single long spine on the inner margin at some distance from 

 the base. Telson (fig. 4^) three and a half times as long as broad, distally narrow, at the 

 narrowest place somewhat less than half as long as broad near the base and the distal third 

 with the lateral margins conspicuously diverging towards the end; the cleft, which occupies less 

 than one-sixth of the total length, has the proximal part laterally marked off, triangular, with 

 an extremely narrow slit at the bottom. Judging from the small incisions along the lateral 

 margins of the telson each margin has possessed six spines much or very much longer than 



