464 SUMMARY OF CURRENT RESEARCHES RELATING TO 



In tlic walla of tho gastrozooid tliore is a deep layer of yellowish gra- 

 uulations. The crystals of gnauiu which were discovered by Kolliker 

 in tho white platocome from the canals which traverse the cnidoblast ; 

 if, tlicrcfore, these elements give indication of a renal organ, we must 

 seat that in the canals of the central organ, and not in tho inferior 

 canals or those of the white plate. 



Identity of the two British Species of Cyanea.* — Prof. W. C. 

 M'lutosh gives reasms for believing that the two British species 

 of Cyanea, C. capillata Esch. and C. Lnmnrcldi Peron and Lesu., are 

 identical, the latter being the young condition of the former. 



Chromatology of Actiniae.! — Mr. C. A. MacMunn finds in 

 Actinia mcsemhryanthemum and other species a colouring matter which 

 is provisionally named actiniohnomatin ; it is distinguished by its 

 spectral characters and by its chemical reactions as well as by its 

 functions, from actiniochrome, for it is respiratory, whereas actinio- 

 chrome has no such function. A special colouring matter has been 

 found in Sagartia parasitica, which likewise exists in different states 

 of oxidation. In the mesoderm and elsewhere in A. nicsemhryantliemum 

 there is a green pigment, which ajipears to be biliverdin. Anthea 

 cereus, Bunodes hallii, and Sagartia beUis yield a colouring matter 

 resembling chlorofucin ; this is derived from tlio "yellow cells" 

 which are abundant in their tentacles and elsewhere ; and it is not 

 identical with any animal or plant chlorophyll. When " yellow 

 cells " are present there appears to bo a suppression of those colouring 

 matters which in other species are of respiratory use. 



Porifera. 



Structure of the Skeleton in the Anomocladina-I— Piof. W. J. 

 Sollas gives a preliminary description of the structure of the skeleton 

 in the Anomocladina as seen in Vetulina. 



After boiling in caustic potash the corpuscles of Vetulina are found 

 to exhibit the characters which Zittel first assigned to them. By 

 cutting frozen sections, one corpuscle thick, it is seen that there is as 

 a rule but one kind of node, only this is not produced by the union 

 of the ends of the corpuscular rays, but by the centrum of the cor- 

 puscles, against which the rays of neighbouring coriiuscles abut. 

 About the place of abutment the centrum throws out numerous 

 branched spines, which make interpretation of the structure difficult. 

 In some cases the centrum gives off rays on one side only, and on the 

 other side receives rays only. It then, when isolated, much resembles 

 the stellates of Hulasterella Carter. 



New American Fresh-water Sponges.§ — Under the title 'Thoughts 

 on the Spongidfe ' Mr. H. Mills gives some account of American 

 sponges of the fresh-water group, and describes some new species. 

 These are as follows : — Myenia Everetti, found on Mount Everett, 



* Ann. and Mag. Nat. Hist., xv. (1885) pp. 148-9. 



t Proc. Roy. Soc, xxxviii. (1884) pp. 85-7. 



J Auu. and Mag. Nat. Hist., xv. (1885) j.p. 236-8 1 fig.). 



§ Proc. Amei. Soc. Micr. 7th Aim. Meet., 1884, pp. 131-47 (3 figs.). 



