SCHIZOPODA. 17 



the spine, at any rate in this species, developes late in life, only after the final adult 

 form is reached. 



The species was taken on the homeward voyage of the 'Discovery,' in the 

 extreme southern part of the Pacific Ocean between New Zealand and Cape Horn. 



Sub-Family Nematoscelin^, Holt and Tattersall. 



Genus Thysanoessa, Brandt. 



Thysanoessa macrura. 



(PI. HI., Figs. 1-12). 



Thtjsanoessa macrura, G. 0. Sars, 1883 ; id. (1885) ; Ortmann, 1893 ; Stebbing, 1900 ; Holt and 

 Tattersall, 1906 (1) ; Coutiere, 1906. 



Localities of capture'^ : — 



Winter Quarters. 



No. 4 Hole, 47 specimens, 7-18 mm. 

 No. 8 Hole, 40 „ 8-21 mm. 



No. 12 Hole, 2 „ 7 and 20 mm. 



From River Koettlita, 2. 1. 03, 6 specimens, 9-14 mm. 

 Outward or Homeward Journey. 



Lat. 61° 46' S., long. 141° 12' E., 16. 11. 01, 18 specimens, 14-20 mm. 

 Lat. 57° 25' 30" S., long. 151° 43' E., 20. 11. 01, 35 specimens, 12-22 mm. 

 Lat. 54° 1' 15" S., long. 170° 49' E., 27. 12. 01, 1 specimen, 6 mm. 

 Lat. 61° 13' 30" S., long. 173° 33' E., 31. 12. 01, 30 specimens, 12-19 mm. 

 Lat. 66° 52' 9" S., long. 178° 8' 15" K, 3. 1. 02, 3 specimens, 8-9 mm. 

 Lat. 70° 29' 27" S., long. 168° 51' 46" E., 26. 2. 04, 1 specimen, 28 mm. 

 Lat. 49° 40' S., long. 172° 18' 30" W., 12. 6. 04, 2 specimens, 8-12 mm. 

 Lat. 58° 49' 45" S., long. 154° 48' W., 24. 6. 04, 4 specimens, 10 mm. 

 Lat. 59° 34' 30" S., long. 106° 28' 12" W., 28. 6. 04, 3 specimens, 7 mm. 

 Lat. 55° 44' S., long. 95° 43' 30" W., 1. 7. 04, 3 specimens, 6-8 mm. 



Form (Fig. 1) of the body rather slender. 



Carapace (Fig. 1) with *a single- rather long slender spine on the lower lateral 

 margin posterior to the middle, just above the origin of the sixth thoracic limb ; 

 antero-lateral corners acute and somewhat produced; anterior margins very concave 

 and produced forwards into a long, slender, acute rostrum which reaches beyond the 

 eyes and far beyond the middle of the basal joint of the antennules ; there is a low 

 keel on the anterior part of the carapace behind the rostrum, and a very faint 

 gastro-hepatic groove. 



Pleon (Fig. l) rather elongate, narrow and attenuate; segments unarmed; sixth 

 segment equal to or slightly less than the combined lengths of the preceding two ; 



