REPORT ON THE AMPHIPODA. 941 



Genus Tritseta, Boeck, 187G. 



1870. Lampra, Boeck, Crust, amph. lior. ct arct., p. 108. 



1871. Atylus (?), Metzger, Die wirbellosen Meeresthiere der ostfriesischen Kiiste, p. 28. 



1875. Dexamins, Stubbing, Ann. and Mag. Nat. Hist., ser. 4, vol. xv. p. 1 (sup. copy). 



1876. Tritseta, Boeck, De Skaud. og Arkt. Amph., p. 317. 



1878. Atylus, Stebbing, Ann. and Mag. Nat. Hist., ser. 5, vol. ii. p. 370. 



1880. Pohjcheria, Haswell, Proc. Linn. Soc. N.S.W., vol. iv. p. 345. 



1880. Dexamine, Nebeski, Beitrage zur Kenntniss der Amph. der Adria, p. 35. 



1882. Pohjcheria, Haswell, Catal. Australian Crustacea, p. 262. 



1882. ,, Thomson, Trans. New Zealand Inst., vol. xiv. p. 233. 



1882. Lampra, Sars, Oversigt af Norges Crustaceer, p. 26. 



1882. Atylus (pars ?), Sars, Oversigt af Norges Crustaceer, p. 101. 



1886. Dexamine, Gerstaecker, Bronn's Klassen und Ordnungen, Bd. v. Abth. ii. p. 508. 



1886. Tritseta, Norman, Museum Normanianum, pt. iil p. 15. 



1887. „ Chevreux, Catal. Crust. Amph. Bretagne, p. 16. 



For the definition of the genus, see Note on Boeck, 1876 (p. 454). The type species 

 of the genus is Atylus gibbosus, Spence Bate ; Boeck observes that Dexamine brevitarsus 

 [brevitarsis], Grube, also belongs to it ; it will further include the species Dexamine 

 antarctica, Stebbing, and probably also Atylus falcatus, Metzger, and Dexamine 

 dolichonyx, Nebeski. Pohjcheria tenuipes, Haswell, Pohjcheria brevicornis, Haswell, 

 Pohjcheria obtusa, Thomson, are, I think, synonyms of Tritseta antarctica, Stebbing, and 

 Atylus uncinatus, Sars, seems to be a synonym of Tritseta falcata, Metzger. 



Tritseta kergueleni, n. sp. (PL LXXXIIL). 



Rostrum minute, back of perseon broad, pleon carinate except on the front part of 

 the first segment ; animal globose when the head and tad are drawn towards one 

 another, but with the legs remaining exserted. The first three pleon-segments with the 

 lower margins spined, forming an angle with the hind margin, which is not acute or 

 outdrawn ; the three following segments by the dorsal processes of the fourth and sixth 

 presenting the profile of an aged human face. (Compare Note on Rondelet, 1554, p. 3.) 



Eyes round-oval, with numerous ocelli, situated near the slight lateral lobes of the 

 head, dark in the specimens preserved in spirits. 



Upper Antennae. — First joint shorter than the head, not twice as long as thick, 

 second joint twice the length of the first, not tapering regularly, but thicker in the 

 basal than the distal Half, the lower edge of this and the preceding joint having several 

 setee ; the third joint very small, not much thicker than the proximal, nor much longer 

 than the distal, joints of the flagellum ; flagellum of twenty joints, increasing in 

 length and decreasing in thickness, though not quite regularly, to the terminal joint 

 which is short ; each, the last excepted, carries a cylinder longer than the joint. 



