32 DISCOVERY REPORTS 



Genus Acidostomella, Schell. 

 Schellenberg, 1926 b, p. 197. 



As pointed out below, the possession of a 2-jointed mandibular palp as originally 

 described must be regarded as an unconfirmed character of the genus. No accessory 

 branchiae. 



Phoxostoma, Brnrd. (1925), is distinguished by the mandibular palp being set far back 

 at the base of the trunk, the very short unguiform 4th joint of the palp of the maxilliped, 

 and by having no groove between the upper lip and the epistome. The peculiar bulbous 

 expansion at the base of the 2nd joint of the palp of maxilla 1 is not found in Phoxostoma, 

 though this joint has the same stiff knife-like character as in Acidostomella. 



Acidostomella cultrifera, Schell. 

 Schellenberg, 1926 b, p. 197, fig. 1. 



Occurrence: 1. St. 39. South Georgia. 1 $ 9 mm., 1 juv. 4-5 mm. 



2. St. 160. Shag Rocks. 1 $ 8-5 mm. 



3. St. WS 27. South Georgia. 2 $$ 7 mm. 



4. St. WS 33. South Georgia. 1 $ 8 mm., 1 juv. 4-5 mm. 



Remarks. Agreeing with the 'Valdivia' specimen in all respects, except that the 

 mandibular palp is 3-jointed. The 3rd joint is two-thirds the length of the 2nd and is 

 setose as usual. The apex of the 2nd joint bears setae as in Schellenberg's figure, and it 

 would seem that the absence of a 3rd joint was accidental. Inner ramus of uropod 

 2 constricted. Schellenberg (193 1 , p. 22) now regards this form as synonymous with 

 Socarnoides kergueleni, Stebb. 



Distribution. Kerguelen, 5-10 m. 



Genus Acontiostoma, Stebb. 

 Stebbing, 1906, p. 15. 



Acontiostoma marionis, Stebb. 



Stebbing, 1888, p. 709, pi. xxx and p. 714, pi. xxxi (magellanicum, = juv.). 

 Stebbing, 1906, p. 15, fig. 4 and p. 15 (magellanicum). 

 Stebbing, 1914, p. 356. 

 Chilton, 1912, p. 462. 

 Schellenberg, 193 1, p. 5. 



Occurrence: St. 55. Falkland Islands. 1 ? with embryos 10 mm. 



Remarks. The embryo has 1-2 spine setae on uropod 3 and two spines on the telson, 

 but lacks the hump on pleon segment 4. These features and the finding of an adult 

 marionis in the Magellanic region support the view that magellanicum should be re- 

 garded as the young of marionis. 



The colour is noted as "pure white with pink antennae". This seems to show that 

 Chilton's endeavour to identify "bright red" specimens from New Zealand with this 

 species requires further investigation. 



