32 



The diagnoses here given of the several species have chiefly been drawn up 

 from adult female specimens, the males affording, as a rule, no particular characters 

 availble for the specific distinction. 



14. Cyclops strenUUS, Fischer. 

 (PI. XVI). 



Cyclops strenuus, Fischer, Bulletin tie la Societe Imper. d. Nat. de Moscow, Vol. XXIV, p 419 



PI. IX, figs. 1221. 



Syn . l ) ? Monoculus qvadricornis rubens, Jurine. 

 ? Cyclops pictus, Koch. 



qvadricornis, Lilljeborg. 

 brevicaudatus, Glaus. 

 Clausi, Lubbock. 



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

 division oblong oval in form, greatest width about equal to half the length and 

 occurring in the middle. Cephalic segment only slightly longer than the 4 suc- 

 ceeding segments combined, and narrowly rounded in front. Lateral parts of 

 penultimate trunk-segment terminating in a short tooth-like projection turned 

 somewhat outwards. Last trunk-segment angularly produced laterally. Tail some- 

 what exceeding half the length of the anterior division ; genital segment conspicu- 

 ously dilated in front, though the width is somewhat less than the length. Caudal 

 rami moderately slender, exceeding in length a little the last 2 segments combined, 

 and slightly divergent, being linear in form, and each provided dorsally with a 

 distinct longitudinal keel, inner edge finely ciliated; seta of outer edge rather 

 small and not much remote from the end ; apical setae comparatively short, the 

 inner medial one only very little longer than the outer and scarcely twice as 

 long as the corresponding ramus, seta of inner corner not much longer than that 

 of the outer. Anterior antennse of moderate length, reaching, when reflexed, to 

 the middle of the 2nd segment, and composed of 17 joints. Natatory legs with 

 3 spines outside the terminal joint of the outer ramus of 1st and 2nd pairs; 

 inner edge of same joint carrying in 1st pair 3, in the succeeding pairs 4 setae. 

 Inner ramus of 4th pair moderately slender, with the outer apical spine some- 

 what exceeding half the length of the inner. Last pair of legs with the distal 

 joint not twice as long as it is broad, lateral spine rather strong and attached 

 about in the middle of the inner edge. Ovisacs comparatively large, oval in 

 form, and borne closely appressed to the sides of the tail. Seminal receptacle 

 transversely truncated in front. 



*) Many other synonyms have been given in the work of Dr. Schmeil. But as he 

 evidently has combined several species under the name strenuus, only those synonymes are here 

 quoted, which more strictly may refer to the species here under consideration. 



