56 



such places, by heavy storms or excessively high tides, are exposed to some ad- 

 mixture of salt water. 



Distribution. British Isles (Brady), coasts of Sweden (Lilljeborg), France 

 (Canu), Madeira (Fischer), Kerguelen Islands (Brady). 



Gen. 15. ZaUS, Goodsir, 1845. 



Generic Characters. Body short and broad, flattened, with the segments 

 of the anterior division lamellarly expanded laterally. Rostral plate broad, sub- 

 truncate at the tip. Last pedigerous segment very small, without any distinct 

 epimeral plates. Urosome narrower than the anterior division, though having the 

 anterior segments somewhat expanded laterally; genital segment in female with 

 distinct traces of a subdivision. Caudal rami short, with the normal number of 

 setae. Anterior antenna in female 9- articulate, terminal part comparatively short; 

 those in male strongly prehensile. Posterior antennae well developed, with the 

 spines of the terminal joint in most cases densely fringed with cilia on the one 

 edge; outer ramus comparatively small, biarticulate. Oral parts on the whole 

 resembling in structure those in Harpacticus: posterior maxillipeds, however, 

 comparatively smaller. First pair of legs, as in Harpacticus, with both rami 

 distinctly prehensile and of very unequal length, the outer one being much the 

 longer and biarticulate, tipped by a number of strong claws. The 3 succeeding 

 pairs rather slender, and of exactly same structure in the two sexes. Last pair 

 of legs more or less extended laterally, distal joint comparatively large, inner 

 expansion of proximal joint in female very broad, though not much prominent, 

 in male rudimentary. Ovisac broad, flattened. 



Remarlcs. This genus, established as early as the year 1845 by Goodsir, 

 has by most authors been referred to the family Peltidndos, on account of the 

 broad flattened body. The several appendages, however, are built upon the very 

 same type as in the genus Harpacticus, and the present genus ought therefore 

 more properly to be included in the family Harpactiddce as here defined. It may 

 be noted here, that one of the characters assigned to this genus by Prof. Brady, 

 viz., "head distinct from cephalothorax" does not hold stand. The head is in 

 reality, as in most other Harpacticoids, wholly united with the 1st pedigerous 

 segment; nor is the outer ramus of the 1st pair of legs, as indicated by that 

 author, 3-articulate, but like that in Harpacticus, only composed of 2 joints. 



