r 
T;. genus Cysteosoma, founded in the year 1842 by F. E. 
GUÉRIN-MEÉNEVILLE !), seems to be one of the rarest among the 
Amphipoda Hyperiidea, as only very few specimens belonging 
to it have been quoted in the literature or captured during 
the different exploring expeditions of the last time. 
DANA ?), in his systematical arrangement of the Crustacea, 
mentions it without any description as belonving to the subtribus 
Hyperidea, 1st family: Hyperide, 2 subfamily: Hyperine. 
SPENCE-BATE?) know the animal only from the description 
of GUÉRIN-MÉNEVILLE. He places it in the family Hyperidez. 
One large specimen was captured 1853 by the Swedish 
Captain MELLENBORG in the Indian Ocean, another in 1870 by 
the Danish Captain ANDRÉA at the west-side of Australia. 
During the circumnavigation of H. Brit. M. S. Challenger four 
or five specimens were caught in different parts of the Atlantic. 
Mr R. Von WILLEMOKs-SUHM, the too early deceased zoolo- 
gist of the Challenger-expedition, proposed for the animal the 
new generic name Thaumops?), because he did not know the old 
description of GUÉRIN-MÉNEVILLE. Afterwards?) he restored the 
name Cystisoma and placed all the specimens captured during 
the voyage in the old species of GUÉRIN, C. Neptunus. He 
did not try to prove the identity of the different specimens 
in his rather imperfect descriptions, and, for mMyj part, ci 
am convinced that the specimen first described as Thaumops 
1) In Revue zoologique, par la société Cuverienne, publiée sous la direc- 
tion de M. F. E. GUÉRIN-MENEVILLE. Année 1842. Paris 1842. p. 215. 
He writes the name »Cystisoma», which must be corrected into Cysteo- 
soma. 
2) In United States Exploring Expedition. Crustacea. vol. 2, Philadel- 
phia 1852, p. 1442. 
3) In Catalogue of the specimens of Amphipodous Crustacea in the col- 
lection of the British Museum. London 1862, p. 311. 
+) In »On a new Genus of Amphipod Crustaceans», in Phil. Trans. of the 
Royal Soc. of London, vol. 163; part 2. London 1874, p. 629 and 637. 
3) In. >On some Atlantic Crustacea from the Challenger-Expeditiomn>», in The 
Trans. of the Linnean Soc. of London. Second Series. Vol. 1, part 1. 
London 1875, p. 24. 
