122 DISCOVERY REPORTS 



on each lateral process. The palp is again six-jointed, the terminal segment being equal 

 to the second (Fig. 66 b). It is perhaps of interest to note that the egg mass in this 

 instance is single and carried on both ovigers. 



For the present it is advisable to refer all these forms to a single species because of 

 the variation that occurs typically in the terminal segment (or segments) of the palp in 

 T. pfefferi. The specimens from Gough Island and that from Tristan da Cunha, 

 although found beyond the northernmost limits of the sub-Antarctic Zone, can hardly 

 be distinguished from the South Georgian specimens — except as regards the egg mass 

 and the palp. The specimens from the Magellan district include no ovigerous males, 

 but the walking legs of some of the females contain developing ova, so that it is highly 

 probable that adults do not exceed i mm. in trunk length. The smaller ratio between 

 the lengths of the second tibia and tarsus plus propodus can hardly be regarded as 

 of specific importance. Caiman (1915, p. 59, figs. 13 and 14) found a similar type 

 of variation in Achelia spicata, although in that case the specimens were (with two 

 exceptions) from one locality. The numerous specimens from the hulk of the ' Great 

 Britain' are a pure culture. In such a limited area close inbreeding doubtless occurs. 



The breeding season appears to vary somewhat, males from the first two stations were 

 carrying larvae in October and December; the single male from Gough Island was 

 carrying eggs as early as July. 



Measurements {mm.) 



<s (St. cj a 



Length of proboscis ... 

 Greatest width of proboscis 

 Length of trunk 



Width across second lateral processes 1-75 0-9 i-i 



Length of abdomen 

 Length of chelophore 

 Third leg: 



Coxae 



Femur 



First tibia ... 



Second tibia 



Tarsus and propodus 



Claw 



Auxiliaries ... 



WS 25) (St. 53) (St. 124) 



1-2 0-55 0-82 



0-55 0-3 0-4 



i'65 0-8 i-i 



07 0-33 0-4 



0-2 0-13 0-13 



1-6 07 0-95 



1-8 073 i-o 



2-05 079 1-2 



2-4 08 1-3 



1-2 0-6 075 



0-5 0-3 0-25 



0-35 0-15 0-2 



Distribution. South Georgia, the Falkland Islands, Gough Island and Tristan 



da Cunha. 



Genus Rhynchothorax, Costa 



Rhynchothorax australis, Hodgson. 



Hodgson, 1907, p. 57, pi. viii, fig. 3; 1915, p. 148. 

 Caiman, 1915, p. 67, fig. 21. 

 Loman, 1923 a, p. 12. 



St. WS 84. 24. iii. 27. 7I miles S 9° W of Sea Lion Island, East Falkland Islands, from 

 52° 33' S, 59° 08' W to 52° 34' 30" S, 59° 11' 00" W, 75-74 m.; c. S. Sh. St. Commercial otter 

 trawl: i immature specimen. 



Distribution. Ross Sea area and the Magellan district. 



