IOO 



SEIJI KOKUBO : 



my friend Mr. T. Sato, by whom they were collected in Lake 

 Kawaguchi (Province Suruga) in August 19 10. Later, I have 

 discovered this species also near Sapporo. Specimens from this latter 

 locality differ from those from Lake Kawaguchi in being a little 

 larger in size, besides being slightly different in the structure of the 

 " Rudermembran." The variations are however to be looked upon as 

 local. 



5. Cyclops signatus Koch. 



PI. II, figs. 16—19. 

 Cyclops signatus, Koch 1841 ; Brady 1878. 

 Cyclops tenuiçornis, Brady 1876. 

 The female, 1.7 mm. long, carries egg-sacs in spring, indicating 

 the breeding season. The blue colouration of the céphalothorax is 

 due to pigments scattered all over that part ; the eyes are red as in 

 other species. The three terminal joints of first antennae are provided 

 with " Rudermembran " on the inner margin. The receptaculum 

 scminis is orange-coloured and is of a mushroom-like shape. The 

 furcal rami are very short and densely haired on the inner margin. 



The recorded habitats of this species are : northern and southern 

 Europe, Scandinavia, Germany, Holland, France, England, and North 

 America. It occurs frequently in the vicinity of Sapporo, but never 

 in any great abundance. 



6. Cyclops flexipes, n. sp. 



Pl. II, figs. 20 — 23. 

 Body broad, widest in front, rather abruptly narrowed backwards. 

 Female 1.40 mm. and male 1.25 mm. in length. First antennae not 

 slender, and almost reaching the posterior border of first body 

 segment, when turned backwards; 12-jointed; 8th, 9th and 12th 

 joints nearly equal in length and longest ; 2nd, 3rd and 6th 

 shorter, but nearly equal in length among themselves ; the remaining 

 6 joints subequal and of a medium length. The anterior 4 pairs of 



