CYCLOPS. 119 



equal in length to the preceding three abdominal 

 segments, which are very short ; external and internal 

 tail setse of about equal length, the innermost of the 

 two principal setae nearly twice as long as the outer, 

 equal to the abdomen in length and minutely plumose. 

 Length -^th of an inch (*98 mm.). 



G. crassicornis seems to be of rare occurrence in 

 Britain, and Sars makes the same remark as to its 

 distribution in Norway, where he has found it 

 only on muddy bottoms, at a depth of about a 

 couple of fathoms, in large sheets of water. My 

 examples, on the other hand, were taken by the hand- 

 net near the edges of lakes of very moderate size, 

 at Bolam (Northumberland), and Tresco (Scilly). I 

 have not noticed the colour of the animal, but 

 Professor Sars states it to be whitish or reddish, 

 with dark blue ovisacs and red eyes. 



(G. Anterior antennae 6-jointed.) 



14. CYCLOPS ^IQUOREUS, Fischer. PI. XIX, figs. 8 10, 

 and PL XXI, figs. 1017. 



Cyclops aquoreus, Fischer. Abhandl. der Akad. der Wissen- 

 schaft. Miinchen, Band viii, p. 654, t. xx, 

 figs. 2629 (1860). 



Brady. Nat. Hist. Trans. Northumberland and 

 Durham, vol. iii, p. 128, pi. Lv, figs. 916 

 (1868.) 



Body compressed, gradually attenuated from before 



