163 



Gen. 39. Macrocheiron, Brady, 1872. 



Generic Characteis. Anterior division of body less pronouncedly 

 depressed than in Lichomolgus; cephalic segment without any distinctly defined 

 transverse suture dorsally. Tail slender, with the apical setae normally developed. 

 Anterior antennae, as in Lichomolgus, 7-articulate. Posterior antennae differing 

 somewhat in structure in the various species, being generally provided with 

 2 apical claws, the inner of which, however, may be setiform. Maxillae with 

 the terminal lappet conspicuously expanded at the base, and the apical lash 

 more or less sharply marked off; palp with 3 or 4 small setae on the end. 

 Anterior maxillipeds with the apical lash less slender and less abruptly 

 bent at the base than in Lichomolgus. Posterior maxillipeds in female com- 

 paratively small, in male very powerfully developed, with the dactylus slender 

 falciform. Natatory legs with the inner ramus in the 3 anterior pairs well 

 developed and longer than the outer, in the 4th pair, however, much reduced in 

 size and composed of only 2 joints, which in some cases may be wholly con- 

 fluent. Last pair of legs with the free joint very long and slender, curving 

 backwards, and provided at the end inside with a slender spine, outside with 

 a much shorter simple bristle. Ovisacs much smaller than in Lichomolgus. 



Remarks. This genus was proposed in the year 1872 by Brady, to 

 include a species (M. fucicolum) found by him on the coast of Northumber- 

 land. The genus was subsequently withdrawn by the same author, and the 

 species upon which it was founded referred to the genus Lichomolgus of 

 Thorell. I think however that there are reasons for restoring the genus in 

 question, as it exhibits several well-marked distinguishing characters indicated 

 in the above diagnosis. Two well-defined Norwegian species referable to this 

 genus will be described in the cequel, and I have also had an opportunity of 

 examining a 3rd species obtained during the Monaco-Expedition from the 

 Sargasso Sea. Moreover several of the exotic species described by A. Scott 

 and referred bv him some to the genus Lichomolgus and some to the genus 

 Pseudanthessius, may more properly be included in the present genus. 



87. Macrocheiron fucicolum, Brady. 



(PI. XCI). 

 Macrocheiron fucicolum, Brady, Nat. Hist. Trans. Northumberland and Durham, Vol. IV, p. 434, 



PI. XVIII, figs. 9 18. 

 Syn : Lichomolgus fucicolus, Brady. 



Specific Characters. Female. Body moderately slender, with the 

 anterior division not much dilated, being regularly oblong oval in outline, and 



