66 



terminal one, antepenultimate joint comparatively short and broad, oval in form, 

 and coarsely denticulated on the hind edge; 2 of the apical setse much more 

 elongated than the others. Anterior maxillipeds strongly built, with the claw and 

 spines issuing from the distal part very coarse and denticulated inside. Posterior 

 maxillipeds, on the other hand, comparatively slender, with the first 2 joints 

 narrower than usual. Natatory legs exhibiting the structure characteristic of the 

 genus, rami comparatively slender, especially those of 4th pair; apical spines of 

 inner ramus in this pair rather unequal, the outer one being much the larger. 

 Last pair of legs with the proximal joint oblong quadrangular in form, and densely 

 clothed inside with small spikes, distal joint somewhat shorter and much narrower, 

 spine of inner edge almost twice as long as that of the outer, both being com- 

 paratively slender and finely denticulated; apical seta still longer and clothed with 

 scattered cilia. Ovisacs comparatively large and borne closely appressed to the 

 body, so as partly to obtect the dorsal face of the tail. Seminal receptacle with 

 the posterior part rather piodnced and narrowly cleft in the middle. 



Body of a more or less dark fuscous colour, with a greenish or bluish 

 tinge and variegated with still darker irregular shadows; caudal rami and ad- 

 joining part of tail bluish green, and also the anterior antennae and the legs 

 tinged with the same colour, ova in the ovisacs generally of a very dark brown hue. 



Length of adult female amounting to 2.50 mm. 



Remark*. -This is one of our largest and most beautiful Cyclopids, being 

 easily recognisable from most other species. The Cyplop* qvadricornis fuscii* of 

 Jurine is in all probability referable to the present species ; but, as noted before, 

 I find it scarcely admissible to appropriate the varietal names appended by that 

 author to his species C. qvadricornis as true specific designations. That the 

 ( 'i/plojis siynatus of Koch is this species, is quite certain, and this has also been 

 admitted by all authors. The name C. corona tus proposed by Clans for this 

 species is of much later date, and must of course cede to that of Koch. 



Occanr-nce. I have met with this handsome species chiefly at the borders 

 of large lakes or in lagunes and ponds left by the reflux of the water in these 

 lakes. In habits, like the other species of the present genus, it is a true bottom- 

 torm, being frequently seen clinging to some object on the ground or to the 

 plants growing upon it. When disturbed it darts away with a sudden bound, 

 and so rapidly that it becomes a matter of great difficulty to catch it by the 

 aid of an ordinary dipping-tube. 



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

 Poland (Lancle), France (Richard), Central Asia (G. 0. Sars), North America 

 (Herrick). 



