25 



the front angle a little less than 90° and besides the tip a little acuminate (fig. 2 a). Eyes 

 somewhat small, narrower than the stalk beyond the middle (fig. 20), as deep as broad, light 

 brownish; the eye-stalks not depressed, with the upper tubercle considerably protruding (fig. 2b). 

 Antennal squama (fig. 2^) four times as long as broad, broadest at the middle, with the inner 

 margin distinctly a litde more curved than the outer; the terminal lobe is well developed, almost 

 half as long as broad, thus considerably overreaching the marginal tooth. 



Exopod of uropods very slender, with nearly the proximal fourth of its outer margin 

 naked, and a small spine at the end of this naked part. Telson (fig. 2d) slightly more than 

 three times as long as broad, with its distal half less narrow than in most other species of the 

 genus, at the narrowest place more than half as broad as its proximal broad part ; the terminal 

 cleft, which occupies one-sixth of the total length, has its proximal part narrow, triangular; the 

 spines along the lateral margins are comparatively few in number, most of them moderately 

 long, only the proximal ones shorter and besides on each side a very short spine between 

 much longer spines. 



Length of the young specimen 8.2 mm. 



Remarks. — This species is in general aspect similar to B. microps G. O. S., but is 

 instantly distinguished by the spinulation of the lateral margins of the telson. The specimen 

 shows no trace of marsupial lamellae and is scarcely more than half-grown, but though the shape 

 of the squama and the telson differs somewhat according to age in the forms of Boreomysis, 

 I think that the description and figures given may be sufficient for the determination of 

 adult specimens. 



10. Boreomysis Sibogce n. sp. PI. II, figs. 3 a — 3t'. 



Stat. 185. September 12. Lat. 3° 20' S., long. I27°22'.9E. HenseN vertical net, from 1536 m. 

 depth to surface. 3 (? 4) specimens. 



Description. — Frontal plate very moderately produced, with the margins somewhat 

 convex (fig. 3«) and the front angle between them nearly 120°, but the end itself is produced 

 into a moderately small, triangular, acuminated rostrum. Eyes moderately large, considerably 

 broader than deep (figs. 3^ — 3(^), broader than the end of the stalk, very light brownish and 

 somewhat shining; eye-stalks short, with the upper .surface flattened and the distal tubercle 

 feebly prominent, seen from above somewhat broader than long, with the lateral margins 

 strongly diverging. Antennal squama (fig. 3^) somewhat less than four times as long as broad, 

 broadest considerably before the middle; the outer margin is straight or at the middle feebly 

 concave; a terminal lobe is rudimentary or wanting, the outer marginal tooth overreaching the 

 transverse end. 



Exopod of uropods (fig. 3^) somewhat slender, with a couple of spines a little beyond 

 the end of the proximal fourth of the outer margin, and this proximal part as usually naked. 

 Telson (fig. 3^') proportionately broad, slightly more than three times as long as broad, at the 

 narrowest place almost half as broad as slightly beyond the base and distinctly broader near the 

 end than somewhat before the bottom of the cleft; the terminal cleft, which occupies one-fourth 



SIBOGA-EXPEDITIE XXXVII. 4 



