JAPANESE FRESHWATER CYCLOPID.E. 



99 



measuring only about 0.85 mm. in length. The body is nearly 

 colourless excepting the red eyes and the greenish intestine. The 

 breeding season falls in June as shown by the females carrying 

 egg-sacs of a dark-bluish colour. The seta with which the first joint 

 of first antennae is provided, is very long and conspicuous as shown 

 in fig. 8. The seta of the fourth joint is not so prominent as 

 represented in a figure given by Brady in his work. cl) Furthermore, I 

 have not been able to detect the hairs which Brady observed at the 

 base of fifth foot. The two egg-sacs, each containing 15 — 16 eggs, are 

 so disposed that they come in contact on the dorsal surface of 

 abdomen. 



My specimens were obtained in Lake Bivva, in Lake Kawaguchi, 

 and in Hokkaido. 



4. Cyclops leu emartri G. O. Sars. 

 Pl. II, figs. 13 — 15. 



Cyclops laickartii, G. O. Sars 1883. 

 Cyclops Scourfreldi, G. S. Brady 1891- 



The body is very slender, the breadth decreasing from head 

 posteriorly to the end of thorax. The female is 1.35 mm. long. The 

 formula of first antennae is similar to that of Cyclops strenuus, being 

 composed of 17 joints, of which the terminal two are much longer 

 than any other and are provided each with a " Rudermembran " 

 along the inner margin. The " Rudermembran " of terminal joint is 

 not only serrated on margin bub is also deeply notched in the 

 middle (Fig. 15). The second joint of first maxilliped presents 

 minute crenulation on the posterior margin. The receptaculum seminis 

 is T-shaped. 



For the first specimens of this intresting species I am indebted to 



(1) G. S. Brady. — A revision of the British species of freshwater Cyclopidae and 

 Calamidae. P. 20. London, 1891. 



