ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 717 



which are known by morphological and palaeontological evidence to be 

 old generalised types. The most modified males are those of the 

 highly-evolved hermaphrodite, or female forms. A classification fully 

 supported by the characters of both sexes rests on a broader basis than 

 one that ignores the males. 



Headless Spermatozoa of Cirripeds.* — E. Ballowitz finds that the 

 ripe spermatozoa of Balanus and Lepas are without "heads." He has 

 studied in particular the spermatozoa of B. improvisus, which are simple, 

 slightly curved threads, with a terminal piece but with no differentiated 

 " head. 1 ' It is possible that the chromatin of the spermatocyte nucleus 

 is in one of the two (light and dark) fibres that make up the spermatozoon. 



New Devonian Isopod.f— George H. Carpenter and Isaac Swain 

 describe Oxyuropoda Ugioides g. etsp. n., a fossil Isopod from Kiltorcan 

 Hill, County Kilkenny. It is superficially like Ligia, but seems to show 

 affinities with the Chelifera. It may be a palaeozoic link between 

 Chelifera and Oniscoidea, and in certain features it resembles Serolidas. 



Annulata. 



Breeding of Nereis japonica.+ — Akira Izuka gives an interesting 



account of the breeding habits and development of Nereis japonica, a 



Lycorid Annelid, closely allied to N. diversicolor, but differing in the 



arrangement of the paragnathi, in the greater size of the falcate bristles, 



and in the possession of a distinct lens in the eye. The breeding habit 



is also different, and the author regards the Japanese worm as a new 



species. X.japotiica occurs very abundantly in the Kojiina Gulf, and 



in the rivers leading into it. It is extensively used, in its mature state, 



for manure, and in some localities it is used for bait. The worms 



burrow in the sand to a depth of about a foot or more, but emerge from 



their retreats at flood-tide, and creep actively about the bottom, feeding 



voraciously on aquatic animals and plants. When disturbed they swim 



rapidly with a wave-like movement. Fully mature worms attain a 



length of 110-120 mm. The number of segments does not exceed 120. 



The sexes are easily distinguishable, the females being deep green on 



the dorsal surface, and a greenish-yellow on the ventral surface, while 



the males are light greenish-yellow dorsally, and pinkish-white on the 



under surface. The eggs, or spermatozoa, are discharged when the worm 



is swimming at the surface, and sink gradually to the bottom. The 



spermatozoa are found adhering in large numbers to the gelatinous 



envelope of the ovum. The cleavage process agrees in general with that 



described by E. B. Wilson for X. limbata, but it seems to proceed much 



more slowly. With respect to the swarming habit of the mature worm, 



the author's observations confirm what has long been known from the 



experience of fishermen, that swarming occurs in December, usually in 



one period, lasting a few days ; that it begins on the night before 



the new or full moon in the middle or latter part of the month, and 



that it invariably takes place at midnight just after flood-tide. Very 



* Zeitschr. wiss. Zool., xci. (1908) pp. 420-6 (1 pi.). 



t Proc. R. Irish Acad., xxvii. Section B (1908) pp. Gl-7i (1 pi, and 1 fig.). 



% Ann. Zool. Japon, vi. (1908) pp. 294 305 (4 figs.). 



