184 U.S. NATIONAL MUSEUM BULLETIN 2 58 



and so does L. bonairensis. Hurley (1963) suggests that the latter 

 should be transferred to Socarnella. On the other hand, the suggested 

 aggregation of all of these species and genera would necessitate 

 removal of mono ty pic Socarnella, with its type S. bonnieri, to Ly- 

 sianassa if reexamination of it proves the simplicity of its gills and 

 the lysianassid-like upper lip and epistome. 



Uropod 2.- — -There is a difference of opinion as to the generic 

 value of the constriction of the inner ramus. Stebbing (1906) cited 

 its presence as a generic character, but the type species of Lysianassa 

 is obscure, and L. plumosa, as drawn by Sars (1895), lacks such 

 constriction, although Sars is known to have overlooked this condi- 

 tion in other species of amphipods. Hurley (1963) attributes con- 

 siderable significance to this constriction in his key to the subfamily 

 Lysianassinae, thus segregating Pronannonyx and Socarnella from the 

 Lysianassa-complex. Gurjanova (1962) considers such ornamentation 

 as interspecific in her analysis of the genus Anonyx and shows signifi- 

 cant intraspecific transitions in the development of this character. 

 Thus, it is regarded as of no generic value in Lysianassa and its 

 allies. 



Uropod 3. — A plethora of variation and intergradation in this 

 appendage, from a long to short and from a simple to lamelliform 

 peduncle, indicates the uselessness of the extreme conditions as generic 

 characters. Just those species now assigned to Lysianassa show most 

 of the extremes. The uni- or biarticulate condition of the outer ramus, 

 with its intergrading stage shown by Hurley (1963) for Lysianopsis 

 alba, is considered to be of no generic significance, although Hurley 

 utilizes the variable in his key to Lysianassinae to distinguish several 

 genera (e.g., Socarnes as opposed to Socarnopsis in train from couplet 

 11, p. 66). 



Upper lip and epistome. — The upper lip of all the genera is 

 produced forward strongly, although it is conspicuously shorter in 

 Aruga dissimilis, for example, and in several species such as A. 

 dissimilis, Lysianassa bonairensis, and L. longicornis the epistome 

 projects in varying degrees along with the upper lip. There is no 

 qualitative point at which to separate generically these examples of 

 intergradation, despite J. L. Barnard's (1955c) hesitation in regard to 

 Aruga dissimilis. 



Kinds of Lysianassa. — A number of subdivisions of Lysianassa 

 may be seen in the accompanying table and these could be subdi- 

 vided further using characters of maxillae, maxilliped, male second 

 antennae, and uropod 2. Because the lamelliform state of the peduncle 

 of uropod 3 is so variable each group has been further divided only 

 to categories A and B. 



