1318 THE VOYAGE OF H.M.S. CHALLENGER. 



standing unless taken in connection with the definition of the genus " Tliaumatops," 

 given in the same work as follows : — 



" Head very large, bordered with a serrated crest around the middle. First two 

 pairs of pereiopoda [First and Second Gnathopods] cheliform. Second pair of uropoda 

 are totally wanting. The interior rami are coalesced in both existing pairs of uropoda." 



Genus Cystisoma, Guerin-Meneville, 1842. 



1842. Cystisoma, Guerin-Meneville, Revue zoologique, juillet 1842, p. 214. 

 1852. „ Dana, Amer. Journ. Sci. and Arts, ser. 2, vol. xiv. No. 41. 



1852. „ Dana, U.S. Explor. Exped., vol xiii. pt. ii. pp. 981, 1442. 



1862. Cystosoma, Spence Bate, Brit. Mus. Catal. Amph. Crust., p. 311. 



1873. Thaumops, v. Willemoes Suhni, Proc. Roy. Soc. Lond., vol. xxi. p. 206. 



1874. „ v. Willemoes Suhm, Phil. Trans. Roy. Soc. Lond., vol. clxiii. pp. 629, 637. 



1874. Cystosoma, v. Willemoes Suhm, Nature, voL ix. p. 182. 



1875. Thaumatops, von Martens, ZooL Record for 1873, vol. x., Crustacea. 

 1875. Cystosoma, v. Willemoes Suhm, Zeitschr. f. wiss. Zool., Bd. xxv. p. 37. 



1875. Cystisoma, v. Willemoes Suhm, Trans. Linn. Soc. Lond. (Zool.), ser. 2, vol. i. pt. i. p. 24. 



1876. ,, v. Willemoes Suhm, Proc. Roy. Soc Lond., vol. xxiv. p. 570. 



1877. Cystosoma, Wyville Thomson, The Atlantic, vol. i. p. 129. 



1879. „ Pagenstecher, Sammlung gem. wissensch. Vortrage, ser. xiv. Hft. 315, 316, 



p. 39. 

 1885. Cysteosoma, Bovallius, Mimonectes, A Remarkable Genus of Amph. Hyper., p. 2. 



1885. Cystosoma, Stebbing, Narr. Chall. Exp., part ii. p. 622. 



1886. Thaumatops, Bovallius, On the genus Cysteosoma or Thaumatops, Bihang till K. Svensk. 



Vetensk. Akad. Handl., Bd. 11, No. 9. 



1886. Cystosoma, Gerstaecker, Bronn's Klassen und Ordnungen, Bd. v. Abth. ii. p. 490. 



1887. Tliaumatops, Bovallius, Systematical List of Amph. Hyper., Bihang till K. Svensk. 



Vetensk. Akad. HandL, Bd. 11, No. 16, p. 14. 

 1887. „ Bovallius, Arctic and Antarctic Hyperids, Vega-Exped., Bd. iv. p. 557. 



For the original definition of the genus Cystisoma. see Note on Guerin-Meneville, 

 1842 (p. 196); this may be compared with the account of the earliest described species, 

 Oniscus spinosus, in the Note on J. C. Fabricius, 1775 (p. 40). For the definitions 

 successively given for Thaumops, see Notes on v. Willemoes Suhm, 1873 (p. 423), 1874 

 (p. 440). The definition of the genus under the name Thaumatops given by Bovallius 

 in 1887 has been quoted above ; in 1886 he defined it as follows : — 



" The body is hyaline, the segments distinctly separated from one another (except 

 the two first pereional segments of Th. Neptunus and Th. pellucida, which are 

 coalesced). The epimerals are only indicated. 



" The head is large, more or less rounded, tumid. The eyes are large, occupying 

 almost all the upper surface of the head. 



" Only the first pair of antennae are developed, straight, few-articulated. The 

 second pair are represented by two small tubercles. 



