190 THE SCHIZOPODA. 



as to GnatJiophausia zoea Will.-Suhm, Sergestes ardicus Kr., and Sergestes robustus 

 Smith, "that small specimens are often at least found nearer the surface than 

 the larger and that the wholly developed specimens are always only met with 

 in deeper layers." 



B. Suborder MYSIDA. 



BOREOMYSIS G. O. Sara (1869). 

 S. Boreomysis media, sp. nov. 



Plate 1, figs. 2a-2b. 



Sta. 4652. Nov. 11, 1904. Lat. 5° 44.7' S., long. 82° 39.5' W. 400 fnis. to surface. 1 adult female 



(Type). 



Sta. 4655. Nov. 12, 1904. Lat. 5° 57.5' S., long. 80° 50' W. 400 fms. to surface. 1 adult female. 



Sta. 4675. Nov. 22, 1904. Lat. 12° 54' S., long. 78° 33' W. 300 fms. to surface. 1 adult female. 



Description. — Frontal plate very considerably produced (fig. 2a), with 

 the transition between the front margin and the oblique lateral margin consid- 

 erably curved; the front margin is produced in a conspicuous, triangular, acute 

 rostrum. Eyes of very moderate size, brownish, somewhat depressed, scarcely 

 as broad as the end of the stalk, which is a little broader than long and with 

 a triangular process of moderate size on the upper surface. The antennal 

 scjuama somewhat short, only three times as long as broad, with the outer 

 margin nearly straight, the inner considerably convex and the end scarcely more 

 than half as broad as the squama a little behind the middle; the terminal margin 

 somewhat oblique and the outer tooth very distinct. 



Exopod of uropods (fig. 2b) eight times as long as broad, with a couple 

 of spines placed a little beyond the end of the proximal sixth of the outer margin. 

 Telson scarcely three times as long as broad, because its proximal third is very 

 broad; from the end of that third the telson tapers strongly to the beginning 

 of the distal fourth, where it is narrow, only two fifths as broad as at the base; 

 its terminal fourth widens feebly to the end; the incision, which occupies one 

 fifth or one sixth of the whole length, has no angles on its margins and its proxi- 

 mal part is shaped as a triangle with its two sides a little convex. • Each lateral 

 margin from the end of the proximal third to near the distal end is furnished 

 with about 10-11 moderately small spines and 18-20 very small spines, the 

 latter regularly arranged between the former and generally two small spines 

 in each interval (fig. 2b, a) ; along the distal part of the margin the spines are 

 more equal in size, small. 



Length of a female with marsupium (from Sta. 4652) 19.5 mm. 



