116 Carl Bovallius, The Oxycephalids. 



Gen. 1. Xipliocephalus, F. E. Guérin-Méneville, 1841. 



Diagn. The body is much elongated, rod-like. 



The head shows a distinct neck, an egg- or spindle-shaped ocu- 

 lar region, and a much elongated, needle-shaped rostrum. 



The first two pairs of perœopoda are cheliform, and very small. 



The last coalesced ural segment is cylindrical, rod-like. 



The peduncles of the uropoda are much elongated, and very 

 narrow. The inner ramus of the last two pairs is coalesced 

 with the corresponding peduncle. 



The telson is much elongated, and needle-shaped. 



Syn. 1841. Xiphocophahis, F. E. Guérin-Méneville. 8, p. 271. 



1848. Rhabdosoma, A. Adams and A. White. 9, p. 63. 



» Spence Bate. 1862. 20, p. 344. 



» Th. Streets. 1878. 26, p. 286. 



» » C. Claus. 1879. 27, p. 195 (49). 



» » » 1887. 36, p. 73. 



» Th. Stebbing. 1888. 39, p. 1606. 



1858. Macroceplialus, Spence Bate. 18, p. 361. 



1887. Rhabdonectes, C. Bovallius. 35, p. 39. 



The passage relating to the name Xiphocephalus, in the work 

 of Eydoux and Souleyet runs: 



»M. Guérin-Méneville, qui a bien voulu étudier avec nous cette 

 espèce, pense qu'elle devra être séparée du genre Oxycéphale pour 

 former une nouvelle division générique à laquelle on pourrait donner 

 le nom de Xyphicéphale^), qui exprime son principal caractère; il se 

 fonde en cela sur ce que les Oxycéphales véritables ont le corps plus 

 court, de forme différente, et en ce qu'ils ont sept paires de pattes, dont 

 deux didactyles et cinq ambulatoires». 



Adams and White, when they instituted Rhabdosoma, gave scarcely 

 any ampler diagnosis than Guérin-Méneville. They said: 



»We regret that the state of the only specimen in the British 

 Museum is such that we cannot give the generic character with that 

 detail which we should wish. — — — The head is as long as the 

 rest of the body, and ends in a very long beak; from the state of 



1) » Xyphicephale» in the text, but Xiphocephalus is the correct spelling. 



