NEREIS JAPONICA. 



region of body undergo shrivelling, as it does in Ccratoccphale oszvai.* 

 There ean be no doubt, that the persistent condition of parapodia and setae 

 enables the mature worm to swim swiftly through water as in the 

 immature stage. 



The swimming worms may be easily captured cither with the tow- 

 net or hand-net. The native fishermen who capture them in quantities for 

 manure, employ " pyramidal net," a kind of large bag-net commonly used 

 in Kojima Gulf for the capture of lifysis, Pa&neus, crabs or Salanx and 

 other small fishes. The net, as set in frame, is of a pyramidal form, with 

 the mouth at the restangular base of about 2 by 5 htro ; the edges of the 

 pyramid measure about 9 htro in length. This net, when set into use, is 

 fastened to two strong poles planted upright in the bottom, the two 

 shorter sides of the mouth being held vertically and the longer sides 

 horizontally. Thus the net is stretched so as to receive the swarm of the 

 worms coming down along with the ebbing water. 



The mature worm, after being captured, can be easily kept alive for 

 a week or more in shallow wooden vessels placed at a shaded place and 

 containing a small quantity of the water, taken during high tide, just 

 enough to cover the worms. The water must be changed at least once a 

 day, taking care to remove all the injured worms as soon as possible, 

 without which precaution the water will soon become so filled with 

 discharged sexual products as to be detrimental to the health of the 

 worms. Too much water, as also too much light, induces the worms to 

 motion and thus increases the chance of their receiving injuries to 

 the body. 



The sexes are easily distinguishable from the colour of the worms. 

 The females are of a deep green on the dorsal and of a greenish yellow 

 on the ventral side. The males are light greenish yellow dorsally and 

 pinkish white ventrally, blending into a deep pink at the bases of 

 parapodia. 



* Izuka, A. — Observations on the Japanese Paiolo, CcraloCcphak osawai. Jour. Coll. Sci. 

 Vol. XVII. Art. 11. 1903. 



