7 o DISCOVERY REPORTS 



12. St. 184. Palmer Archipelago. Many $$, ovig. ?? and immat. up to 25 mm. 



13. St. 189. Palmer Archipelago (70 metres). 3 <$<$ 16-20 mm., 5 $? 20-27 mm., 

 1 ovig. $ 21 mm. 



14. Ibid. (7 metres). 3 S3 20-27 mm., 1 $ 31 mm., several juv. 6-13 mm. 



15. St. 208. South Shetlands. 2 ovig. ?? 22 and 24 mm. 



16. St. WS 38. South Georgia. 1 $ 20 mm. 



Remarks. The 1st side-plate is strongly produced forwards, and the lower profile of 

 side-plates 1-4 forms a very even, often slightly concave line. 



The colours of nos. 3 and 11 are given as "creamy white with black eyes" and 

 "creamy white, thorax and abdomen scarlet above, eyes black" respectively. 



Schellenberg (1926) has uttered a caution against uniting all the various forms of 

 chilensis under one name, and has wisely adopted names for the various forms. Being 

 against the principle of a trinomial nomenclature, I should prefer to keep them all as 

 species. But the main point is that all records of chilensis should state definitely 

 which form is meant, so that the distribution of each may be determined. 



Distribution. Ross Sea; 'Gauss' winter station; Palmer Archipelago. Probably 

 also South Orkneys and Coats Land (Chilton, 1912). 



Orchomenella charcoti (Chevr.) (Fig. 27/). 



Chevreux, 1913, p. 92, figs. 4-6 (Orchomenopsis c). 



Occurrence: St. 175. South Shetlands. 1 $ with embryos 17 mm. 



Remarks. There is no doubt that this is the form described by Chevreux. The eyes 

 are brown (as preserved), not black as in rossi. The palm of the 1st gnathopod is even less 

 obvious than in Chevreux's figure, in fact the 1st gnathopod might almost be described 

 as simple. The finger of the 2nd gnathopod is stronger, and overlaps the minute distal 

 projection of the 6th joint more than in Chevreux's figure. There are two apical spines 

 on each lobe of the telson, but one is not actually apical, but a little subapical (and not 

 symmetrical on the two lobes), and there are 2-3 lateral spines (also not symmetrical). 

 The carina on pleon segment 4 is more obviously triangular than in Chevreux's figure, 

 resembling closely Stebbing's figure of that of Tryphosa trigonica. The epistome is 

 straighter and not so prominent as the gently gibbous upper lip. 



Although drawn into the synonymy of the polymorphous "species" chilensis by 

 Schellenberg, I think this is worthy of specific rank. The 4th pleon segment, gnathopod 1 , 

 the flattened or slightly emarginate lower hind margin of the 2nd joint of peraeopod 5 

 (which feature is also present in the ' Discovery ' specimen) and the brown eyes enable it 

 to be picked out at once from specimens of rossi. 



Distribution. Palmer Archipelago. 



Orchomenella macronyx, Chevr. (Figs. 27 d, 29). 



Chevreux, 1906, p. 8, figs. 5-7. 

 Chilton, 1912, p. 470. 

 Schellenberg, 1931, p. 43, fig. 22. 



