PESr-BTPTTON OF EPHYDATfA BLEMBINHTA. 81 



of the flesh spicules so charactei'istic of both pluniosa and 

 palmei'i. Though this is a negative character^, combined with 

 the other differences it seems to be a sufficient reason for the 

 formation of a new species, to which I liave given the name 

 blembingia. 



IV. Summary. 



Ephydatia bloml)ingia is an encrusting sponge which 

 grows on vegetable supports. It is pale flesh in colour, and 

 loose in texture. The skeletal spicules are covered with small 

 spines. Flesh spicules are absent unless the small amphioxea 

 (h) be considered to belong to such a category. The spicule 

 fibres are poorly developed, and in the deeper parts of the 

 sponge the spicnles, as a rule, lie about iri'egularly arranged 

 in the tissues. S])ongin is present only in very small quan- 

 tities. The gemmnlos are numerous, but not aggregated in 

 groups. They are situated — each one occupying a cavity of 

 its own — near the surface as well as deeper down in the 

 tissues of the sponge. They are oval in shape, and possess 

 an opening resembling that of a bottle, which is obstructed 

 by a chitinous septum. They are provided with a thick and 

 well-developed coat, in which anqihidiscs of equal lengths are 

 arranged in a single layei-. Tlu> shaft of the nm]5hidiscs is 

 famished with coniciil s])iiics, Inrge in size and situated at 

 right angles to the longitndiunl axis. The outer surface of 

 the discs is convex, and the ninrgin is slightly serrated. Amphi- 

 discs, in all stages of dcn'olopment, are scattered about in the 

 sponge tissue where they are formed. 



Part II. — The Formation of the Gemmule of Ephydatia 

 blembingia. 



I . Introduction. 



When I took the description of E})hydatia blembingia 

 in hand I had no intention of desct'ibing the development of 



VOL. 44, PART 1. NEW SERIES. P 



