270 



wanted , unless we agree to baptise every specimen. For my forth- 

 coming report on the Porifera incalcaria, whicli will be published 

 in the well-known » Fauna and Flora of the Bay of Naples", I 

 have figured a number of spicules of one and the sarae species 

 or even specimen and I hope there agaiu to show to what extent 

 variations and modifications occur, In this short paper I cannot 

 furnish the proof of mauy of my statements , nor even mention 

 the views of other authors. I have taken the trouble to do this 

 carefully in the definitiv work ; for the sponges here after descri- 

 bed the M. S. lies before me , ready for the press ; many of the 

 plates are already printed. What I publish now , is therefore by 

 no means the result of a cursory glimpse at some preparations , 

 but an abstract of the written report. 



As to the technical terms used in this paper I refer to Sollas ^) 

 and to a paper of my own ^). 



Cydonium gigas (O. S.) SoU. 



Syn. 1862 Geodia gigas O. S. 



Cf. Schmidt, Spong. Adriat. Meeres (1862) p. 50 PI. IV figs. 8 & 9. 

 Sollas, Chall. Tetractin. (1888) p. 258—259. 



The shape of this sponge is spherical , sometimes very regular , 

 sometimes very irregular and resembling brains. The surface is 

 smooth or rough. In some specimens large parenchymal oxeas pro- 

 ject beyond the surface; in such cases the sponge feels rough. In 

 others there are few of such spicules , but a large quantity of 

 minute spicules (oxeas and anatriaenes). Apart from the spicules 

 the surface looks like shagreeu. At one or more places a shallow , 

 rarely deep depression is to be seen where the proctions lie con- 

 gregated together. If, what sometimes happens the depression is 

 deep and narrow, an osculum is formed which resembles the os- 



1) 1. c. 



2) On the Canal System of the Homocoela and on the Morphological Value of the 

 Terms Osculum and Pore in Sponges. Tijdschr. Ned. Dierk. Ver. (3). III. 1892. p. 235—242. 



