ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 183 



present, when perforations are along the anterior border, not along the 

 posterior border as in Synaptula. The two large lateral holes in the 

 handle of the anchor plate are absent ; the central hole is larger than 

 Euapta, and rounded, not acute, on the outer edge. The plates are 

 otherwise as in Euapta. The calcareous ring has conspicuous anterior 

 projections. Tentacles and anchors are as in Euapta, and retractors are 

 present. 



Coelentera. 



New Fresh-water Medusoid from China.* — Asajiro Oka describes 

 Limnocodium kaivaii sp. n. from the Yang-tze-kiang, about 1000 nautical 

 miles from its mouth. The umbrella is hemispherical ; the velum 

 projects inwards for about a quarter of the breadth of the sub-urnbrellar 

 diameter ; there are over 256 tentacles of seven different sizes ; the 

 diameter was about 20 mm. The author compares this new form with 

 L. sowerbyi (whose native habitat remains unknown), and with 

 Limnocn ida from Tanganyika, Victoria Nyanza and the Niger. Systemati- 

 cally the affinities of Limnocodium (the generic diagnosis of which is 

 enlarged), are with the Olindias group, and the author is inclined to 

 place it nearer to the Leptomedusae than to the Trachomedusas. 



Hydroids of Madagascar and South-east Africa. t — A. Billard 

 reports on a collection of 38 species, of which six are new, and the chief 

 interest of his report is probably that at least eight of the species are 

 characteristically Australian, while 18 are common to Australia and 

 these South-east African regions. 



-"&* 



Structure and Development of Turritopsis nutricula.J — W. K. 

 Brooks and S. Rittenhouse describe the structure of this Medusoid. It 

 is compared with Gallitiara, and with a new genus (Modeeria in part), for 

 which the name Mccradia is proposed. The ova of Turritopsis arise in 

 the ectoderm of the manubrium ; they grow by the absorption of the 

 primitive ovarian cells, and when mature are densely crowded with large 

 yolk granules. Dehiscence takes place at a definite time, from 5 to 6 

 o'clock in the morning. The egg is spherical and membraneless. Matu- 

 ration and fertilisation occur in the water after the eggs are deposited. 



Cleavage is total and nearly equal, at first regular, afterwards very 

 erratic. A solid morula results, whose cells form a syncytium. Parts 

 of eggs divided during cleavage continue to develop normally in every 

 respect except size. Cell- walls re-appear peripherally and establish the 

 ectoderm, the mesoglcea appears, and the endoderm is late of being 

 differentiated in the internal syncytium. There is some evidence of 

 amitotic division in the late segmentation. 



The planula becomes attached by nearly its entire side, and is trans- 

 formed into a root. The first hydranth develops from a bud from about 

 the middle of the root. The tentacles develop in indefinite whorls, each 

 whorl with four tentacles. 



Annot. Zool. Japon, vi. (1907) pp. 219-27 (1 pi.), 

 t Arch. Zool. Exper., vii. (1907) pp. 335-96 (2 pis.). 

 % Proc. Boston Soc. Nat. Hist., xxxiii. (1907) pp. 129-60 (6 pis.). 



