TANAIDACEA AND ISOPODA— TATTERSALL. 247 



Sub-order GNATHIIDEA. 



Family GNATHIIDAE. 



Genus EUNEOGNATHIA, Stebbing. 



51. Euneognathia gigas (Beddard). 



Anceus gigas, Beddard, 1886 (1), p. 120 ; Beddard, 1886 (2), p. 137, pi. XVIII, figs. 8-10. 

 Eimeognathia gigas, Stebbing, 1893, p. 338, pi. XIV ; Hodgson, 1910, p. 15, pi. I, figs. 3-3&. 



Occurrence. — Station 294, Ross Sea, 74° 25' S.^ 179° 3' E., 158 fathoms, January 

 15, 1913, bottom fauna, one adult male, 12 mm., one Praniza larva, 12 mm. 



Genus GNATHIA, Leach. 



52. Gnathia antarctica (Studer). 



Anceus antarcticus, Studer, 1884, p. i. 

 Gnathia polaris, Hodgson, 1902, p. 241, pi. XXXII. 



Gnathia antarctica, Richardson, 1906 (2), p. 3 ; Richardson, 1908, p. 3 ; Hodgson, 1910, p. 11, 

 pi. I, fig. 2 ; Vanhofien, 1914, p. 486, text-figs. 23 and 24. 



Occurrence. — Station 331, off Cape Bird Peninsula, entrance to McMurdo Sound, 

 250 fathoms, January 14, 1912, bottom fauna, 10 males, one female, five larvae. 



Cumberland Bay, South Georgia, collected by P. Stammwitz, one male, four 

 larvae. 



Remarks. — In his report on the Isopoda of the German South Polar expedition, 

 Vanhoffen (1914) has named two varieties of this widely distributed form, G. antarctica 

 continentalis, a deep-water form with pale eyes found generally in deep water off 

 the Antarctic continent, and G. antarctica insularis, a form with darkly pigmented 

 eyes found in shallow water among the Sub-antarctic Islands. The specimens I have 

 examined do not quite bear out this rigid demarcation. It is true that the specimens 

 from South Georgia all have dark, almost black eyes, but among those from Station 331 

 the larvae are all pale-eyed, but the males show considerable variation in the pigment 

 of the eyes, some specimens having it quite dark and of only slightly less intensity 

 than the shallow-water specimens from South Georgia. 



53. Gnathia hodgsoni, Vanhoffen. 



G. hodgsoni, Vanhoifen, 1914, p. 448, text-fig. 25. 



Occurrence. — Station 331, off Cape Bird Peninsula, entrance to McMurdo Sound, 

 250 fathoms, January 14, 1912, two males. 



Remarks. — Among the numerous specimens of Gnathia collected at Station 

 331, I detected two males which agree completely with Vanhoffen's description of 

 G. hodgsoni. Vanhoffen separated this specimen from G. antarctica, Studer, on (1) the 

 longer curved pre-ocular lobes with their armature of subsidiary spinules ; (2) the more 

 spiny contour of the head and the first three somites of the body ; (3) the coarser 



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