ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 55 



Semper considered this identical with //. atra .lager (1833) from the 

 Celebes. All authors followed Semper till 1905. In the meantime, 

 Ludwig, in 188:3, recognised a species in the West Indies different from 

 the Indo-Pacific form, and failing to identify it with H. floridana 

 Pourtales, created a new species, //. mexkana. The same error was 

 repeated by Theel, in 1886, in making his H. africana. 



Edwards obtained 138 specimens, and submitted every important 

 character to statistical study. The result is that H. floridana Pourtales 

 is re-established as a valid species, with H. mexicana Ludwig and 

 H. africana Theel as synonyms. 



Sudanese Crinoids.* — H. C. Chadwick reports on six species of 

 Antedon collected by Cyril Crossland in the Sudanese Red Sea. 

 None is new, but only two of them have been previously recorded from 

 the Red Sea. 



Ecology of Recent Crinoids.j — A. H. Clark takes a survey of the 

 recorded data in regard to recent Crinoids, with a view to suggesting 

 lines of work which may throw light on the problem of the inter-relation 

 of the Crinoids and the other classes of marine Invertebrates, and on 

 the relation of the Crinoids to marine conditions in general. An 

 analysis of the conditions of the localities in which the large forms 

 occur, shows that the only factor common to them all is a very abundant 

 food supply. In regard to colour the data seem to show that the 

 smaller staiked forms are invariably and unchangeably yellow, and this 

 colour may be, as in the case of parrots among birds, equivalent to a 

 lack of colour. Black is added to the basic colour of Comatulids at all 

 depths, and appears to denote age. Blue is added apparently only 

 within 200 fathoms of the surface. The mosaic forms are all littoral. 

 or shallow-water types. The same species may show different colours 

 according to the bottom on which it occurs, and according to the depth 

 of the water. There is, apparently, a close connection between colour 

 and amount of illumination, the blue increasing with the light. Crinoids 

 are too calcareous to be desirable as food, and it is possible that their 

 brilliant colouring is of advantage in attracting small organisms. 



Ccelentera. 



Antarctic Sea- Anemones.}— Joseph A. Clubb reports on eight 

 species collected by the ' Discovery.' Two are new—Paractis polaris 

 and Ci/stiactis antarctica. In Or i brum octoradiata (Carlgren) there are 

 sixteen brood-pouches, which arise as invaginations of the three layers 

 of the body-wall. Each has an external pore, and usually contains two 

 embryos. 



Stinging by Jellynsh.§— E. H. H. Old reports on several case - 

 the Philippines of unusual symptoms caused by contact with some 

 unknown kind of jellyfish. The unknown irritant or poison brings 



* Journ. Linn. Soc. (Zool.) xxxi. (190S) pp. 44-7. 



f Amer. Nat., xlii. (1908) pp. 710-26. 



- Nat. Antarctic Exped. (Zool.) iv. (1908) 12 pp. (3 pis.). 



§ Philippine Journ. Sci., iii. (1908) pp. 329-33. 



