116 CARL BOVALLIUS, THE OXYCEPHALIDS. 



Gen. 1. Xiphocephalus, F. E. GUERIN-MENEVILLE, 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 perceopoda 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. Xiphocephalus, F. E. GUERIN-MENEVILLE. 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. GLAUS. 1879. 27, p. 195 (49). 



1887. 36, p. 73. 



TH. STEBBING. 1888. 39, p. 1606. 



1858. Macrocephalus, 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. GUERIN-MENEVILLE, qui a bien voulu e"tudier avec nous cette 

 espece, pense qu'elle devra etre separe'e du genre Oxyce*phale pour 

 former une nouvelle division gene'rique a laquelle on pourrait donner 

 le nom de Xyphicephale 1 ), qui exprime son principal caractere; il se 

 fonde en cela sur ce que les Oxyc6phales veritables ont le corps plus 

 court, de forme diffe"rente, 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 GUERIN-MENEVILLE. 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) Xyphicephalev in the text, but Xiphocephalus is the correct spelling. 



