DESCRIPTION OF EPHYDATIA BLEMBINGIA. 



71 



A Description of Ephydatia blembingia, with 

 an Account of the Formation and Structure 

 of the Gemmule. 



Ricliard Evans, M.A., B.Sc. 



With Plates 1—4. 



Contents. 



Part I. — The Morphology, etc., op Ephydatia. blemuingia 



I. Introduction .... 



II. Description of Epliydati a bleinlnni^ia . 



(1) Colour, habits of growtii, and external form 



(2) Skeleton .... 



A. Spicules 



B. Arrangement of spicules to form fibres 

 c. Spongin 



(3) Canal system 

 (i) The structure of the mature gemimile 



III. Affinities of Ephydatia blembingia 



IV. Summary ..... 



Part IT. — The Formation of the Gemmule of EpnY]')ATiA 



BLEMBINGIA. 



I. Introduction ...... 



II. Historical review ...... 



III. Descriptive account of tiie development of the gemmule of Ephy 

 d at ia blembingia 



(1) Origin, etc., of the reproductive part of the gemmule 



(2) Origin, etc, of the cells which form the chitinous layers, etc 



(3) Origin, etc., of the scleroblasts and amphidiscs 



(4) Structure, etc., of the " trophocytes " 



(5) General conclusions . 

 IV. Critical review of previous accounts 



V. Bibliography . . . - 



Description of Plates .... 



72 

 72 

 72 

 73 

 73 

 7G 

 70 



n 



78 

 79 

 81 



81 



82 



89 

 89 

 91 

 92 

 94 

 95 

 96 

 103 

 105 



