43 



Distribution. Sweden (Lilljeborg), British Isles (Brady), Germany (Glaus), 

 jar Island (Lilljeborg), North America (Herrick). 



22. Cyclops capillatus, G. 0. Sars. 



(PI. XXIV). 

 Cyclops capillatiis, G. O. Sars, 1. c., p. 39 



Specific Characters. Female. Body not very slender, resembling some- 

 what in its general form that in C. vulgaris, anterior division regularly elliptical 

 in outline, with the greatest width somewhat exceeding half the length and occurring 

 in the middle. Lateral parts of penultimate trunk- segment of same shape as 

 lose on the 2 preceding segments. Last trunk-segment comparatively small, not 

 >roduced laterally. Genital segment resembling in shape that in C. vulgaris, 

 )eing about as long as it is broad at the base. Caudal rami comparatively 

 slender, almost attaining the length of the last 3 segments combined, and not 

 at all divergent; seta of outer edge rather slender and far from the end, being 

 attached near the middle; middle apical setae slender, the inner one attaining 

 half the length of the body; seta of inner corner scarcely longer than that of 

 the outer. Anterior antennae about the length of the cephalic segment, and 

 composed of only 12 joints, the 7 short articulations intercalated in other species 

 between the 7th and the antepenultimate joint being in the present form by 

 concrescence reduced to 2 elongated segments; lateral setae of the antennae un- 

 usually long and slender. Posterior antennae with the terminal joint considerably 

 longer than the penultimate one. Natatory legs moderately slender, terminal 

 joint of outer ramus in all of them armed outside with 3 spines, inner edge of 

 same joint in 1st pair with 3, in the other pairs with 4 setae; inner ramus of 

 4th pair very narrow, with the terminal joint fully as long as the other 2 com- 

 bined, apical spines of this ramus slender and elongated, the inner one slightly 

 longer than the outer. Last pair of legs with the proximal joint rather broad 

 and expanded, distal joint much smaller, rounded oval in form and having the 

 lateral spine very small. Ovisacs narrow fusiform in shape and greatly diverging. 

 Seminal receptacle with the anterior part transversely oval and evenly rounded 

 in front, posterior part only slightly produced. 



Colour yellowish, with a more og less distinct olivaceous or brownish tinge. 



Length of adult female about 1.80 mm. 



Remarks. This is a very distinct species, though in size and general 

 appearance somewhat resembling C. vulgaris. From this species it is, however, 

 markedly distinguished by the smaller number of joints in the anterior antennae, 



