30 R. NORRIS WOLFENDEX. 



CLAUSOCALANUS (GIESBRECHT). 



CLAUSOCALANUS ARCUICORNIS. 



Clausocalanus arcuicornis. Giesbrecht, Atti. Ace. Lincei Rend., Ser. 4., vol. 4, p. 334. 



Giesbrecht, Fauna u. Fl. Neap. XIX. (1892), p. 50. 

 Giesbrecht u. Schmeil, Das Tierreich, p. 27. 



That this species should occur so far south is rather peculiar. It was found in the 

 collections made at : 



Lat. 49 40' S. Long. 172 18' 30" W. 



Lat. 55 44' S. Long. 95 43' 30" W. 



Lat. 56 12' 45" S. Long. 136 18' 30" W. 



Lat. 57 25^' S. Long. 151 43' E. 



Lat. 58 49' 45" S. Long. 154 48' W. 



Lat. 59 19' S. Long. 120 24' 30" E. 



Lat. 63 5' S. Long. 175 43' E. 



Lat. 84 01' S. Long. 170 49' E. 



and does not differ essentially from the species common in the Atlantic. It has a 

 considerably greater range than was thought, since I can record it from the Irish coast 

 to nearly the Antarctic Circle. 



GAETANUS (GIESBRECHT). 



GAETANUS ANTARCTICUS. 



(Plate III., fig. 6.) 

 Qaetanus antarcficus, Wolfenden, Plankton Studies, Part I. (1905), p. 7. 



Size 8 mm. The body is very robust and dorsally very gibbous. The head and 

 first thoracic segment are coalesced, and together much longer than all the rest. The 

 last thoracic segment carries two short stout curved spines, directed backwards. The 

 head is in its upper part quite square, and with short stout curved spine, directed a 

 little forwards. The abdomen is not a quarter the length of the cephalothorax. 



Anterior antennae not as long as the body, of twenty-three segments, with the 

 eighteenth, nineteenth and twenty-first segments longer than the twentieth, and all 

 joints with very few setae. Hi of the posterior antennae more than half the length of 

 Re. Posterior foot jaws with lamellar process on the first basal. 



Maxillae ; Li 2 and Li 3, each with four bristles ; B 2 with five, Ri small and two- 

 jointed. Re small, and less than half the length of B 2. 



First feet, Re of three segments with three marginal spines, the segmentation being 

 complete ; Ri of only one segment. 



