29 



Sea. All the species are inhabitants of more or less brackish water, though they 

 may be of marine origin, as they are never found in purely fresh water. 



13. Halicy clops magniceps (Lilljeborg). 



(PI. XV). 

 Cyclops magniceps, Lilljeborg. De crustaceis ex ordinibus tribus, etc. p. 204, PI. XXII, fig. 1. 



83-11: Cyclops ceqroreus, Fischer. 



christianiensis, Boeck. 



Specific Characters. Female. Body moderately stout, with the anterior 

 division oblong oval in outline, greatest width about equalling half the length 

 and occurring somewhat in front of the middle. Cephalic segment very large 

 and broadly rounded in front; last trunk-segment only slightly produced laterally. 

 Tail scarcely more than half as long as the anterior division, genital segment 

 nearly of equal width throughout, anal segment shorter than the preceding one, 

 and deeply cleft at the end. Caudal rami about twice as long as they are broad 

 and somewhat divergent; seta of outer edge attached about in the middle; apical 

 setse rather slender, the inner medial one attaining half the length of the body; 

 seta of outer corner shorter than that of the inner. Anterior antennas compara- 

 tively short and stout, being composed of only 6 distinctly defined joints, the 

 first 2 rather dilated, the 3rd quite short, the 4th nearly as long as the outer 

 2 joints combined. Posterior antenna with the terminal joint sub-fusiform in 

 shape, and provided in the middle outside with a well-marked notch, indicating 

 the place where the 2 outer joints have been coalesced. Posterior maxillipeds 

 very small and only composed of 2 joints, the distal one much the smaller. 

 Natatory legs with the terminal joint of the inner ramus not much larger than 

 the middle one, and provided in the 1st pair with 2, in the other pairs with 3 

 spines in addition to the setse; terminal joint of outer ramus having 3 spines 

 outside in the 3 anterior pairs, 2 in the 4th pair. Last pair of legs with the 

 proximal joint imperfectly defined from the segment, distal joint much expanded, 

 spatulate in form, terminal edge obliquely truncated and carrying 4 comparatively 

 short setas, the innermost but one simple, the others ciliated. Ovisacs oblong 

 oval in form and borne closely appressed to the sides of the tail, each containing 

 only a limited number of ova. 



Male much smaller than female, and having the anterior antenna? very 

 strongly built, being composed of 1 1 more or less distinctly defined joints, the 

 last consituting the terminal section and produced in a sharp point. Last pair 

 of legs with the proximal joint more distinctly defined, distal joint only differing 



