54 SUiMMAKY OF QUERENT RESEARCHES RELATING TO 



tuberculatioD, and trend to^Yards the Clypeastroid and Cassidnlid arrange- 

 ment. In any case the Holectypoida iUustrate the process wliich, at one 

 or more stages of geological history, produced a uniform and packed tuber- 

 culation from the solitary series of large tubercles which characterize the 

 Cidaridae. 



Middle Piece of Echinus Spermatozoon in Fertilization.* — Fr. 

 Meves finds that the middle piece accompanies the sperm-nucleus to the 

 vicinity of the female pro-nucleus. When the two pro-nuclei have united 

 and the clear halo or aureole is formed around them, the middle piece is 

 seen within this zone, sometimes directly on the surface of the nucleus. 

 It keeps its shape unaltered for some time. What becomes of it is un- 

 certain, but the author has shown in Ascaris that the middle piece breaks 

 into granules, which mix and eventually unite with the plastochondria 

 of the ovum. 



North Pacific Asteroids.! — Walter K. Fisher has prepared a valuable 

 report on Phanerozonia and Spinulosa from the North Pacific and adja- 

 cent waters. He has dealt with some seven thousand specimens. Seventy- 

 three of the species (76 p.c.) dealt with are confined to the North Pacific. 

 Of the remaining twenty-three, twelve are found in the North Atlantic 

 and the other eleven are practically South American. The huge report, 

 which represents a prodigious amount of work, is finely illustrated. 



Gigantic Form of Auricularia.J — Hiroshi Ohshima describes from 

 Misaki a large Holothurian larva, closely resembling the Auricular ia 

 malibraiichiata discovered by Chun off the Canary Islands. The largest 

 was 15 mm. in length after preservation in formalin. There is a peculiar 

 arabesque arrangement of ciliary bands which have a light violet tinge. 

 The body is transparent, but there are numerous reddish-brown amoeboid 

 pigment-cells. There are numerous wheel-like calcareous bodies. The 

 food-wafting action of the ciliary bands was experimentally verified. 

 The largest specimens showed the primitive ring-canal or the broad flat 

 sac-like hydrocoel. In two specimens there were Trematode parasites in 

 the mid -gut and in the mesenchyme. 



Coelentera. 



Sea-anemones of Aru Islands. §—Ferd. Pax describes Parazoanthus 

 aruensis sp. n. and F. douylasi Hadd. and Shackl. from the Aru Islands. 

 He comments on the small number of Actinians in the Indo-Malayan 

 Archipelago, which is again confirmed by an investigation of the Aru 

 Islands. Alcyonarians abound, but only two species of Actinians were 

 observed. The reason for this remains obscure. 



Life-history of Chrysaora.]] — E. Herouard finds that a cyst is formed 

 below the pedal disc of the scyphistoma, and that this may give rise to 

 a polyp after a resting period of more than three years. The cysts are 



* Anat. Anzeig., xl. (1911) pp. S7-101. 



t U.S. Nat. Mus., Bull. No. 76 (1911) pp. 1-406 (122 pis.). 



i Annot. Zool. Japon., vii. (1911) pp. 347-52 (3 figs). 



§ Abb. Senckenberg. Nat. Ges., xxxiii. (1910) pp. 299-304 (1 pi. and 1 fig.). 



II Comptes Rendus, cliii. (1911) pp. 1094-5. 



