104 * BRITISH COPEPODA. 



3. Cyclops steenuus, Fischer. PL XIX, figs. 1 — 7. 



Monoculus quadricornis rubens, Jurine. Hist, des Monocles, p. 1, 



pi. i, and pi. ii, figs. 1—9 (1820). 

 Cyclops pictus, Koch. Deutschlands Crust., H. xxi, tab. i (fide 

 Sars) (1841). 



— strenuus, Fischer. Bulletin de la Soc. Imp. des Nat. de 



Moscow, torn, xxiv, p. 419, tab. ix, 

 figs. 12—21 (1851). 



— — Sars. Oversigt Ferskvandscopepoder, p. 27 



(1863). 



— quadricornis, Lilljeborg. De crust, ex. ord. trib., p. 150, 



t. xiv, figs. 5, 6; t. xv, figs. 1 — 11; and 

 t. xxvi, fig. 19 (1853). 



— brevicaudatus, Claus. Das Genus Cyclops, p. 34, t. ii, 



fig. 12; Die frei-lebenden Copepoden, 

 p. 100 (1857). 



— — Fric. Die Krustenthiere Bohinens, p. 221, 



fig. 15 (1871). 



Anterior antennge (fig. 1) reaching about to the 

 fourth thoracic segment, only slightly tapering 

 towards the apex ; last three joints much less slender 

 than in the foregoing species ; joints of the posterior 

 antennas short and stout. Joints of the swimming 

 feet destitute of cilia at the margins. Fifth foot 

 (fig. 6) composed of two joints, the first having a 

 moderately long apical seta, the second one very long 

 seta at the extremity, and a spine-like seta on the 

 inner margin. Caudal segments slender (fig. 7), 

 about three times as long as the last abdominal seg- 

 ment. Of the four caudal setse, the outer is the 

 shortest and only about half as long as the caudal 

 segments ; all the setae are finely plumose ; the 

 third seta is the longest, and about once and a half 



