SPONGIA. 169 



double-pointed needle-shaped spicula, very little curved, and 

 uniform in size : they are mostly disposed in lines agreeing with 

 the axis of the fibre, but occasionally cross each other at right 

 angles, especially where a branch is given off. I did not detect 

 a vascular coat on any part of the fibre." Bowerhank. In small 

 specimens there is seldom more than a single osculvun placed to 

 one side and level with the surface ; but in larger specimens 

 there is an osculum to every lobe. 



On the under surface of stones the growth of the sponge is 

 modified by its untoward position, and it then forms a loosely 

 reticulated spongy crust, from the eighth to about a quarter of 

 an inch in thickness, perforated with several fecal orifices which 

 remain always level with the surface. 



Montagu's description of the species is as follows : " This 

 sponge is firm and elastic ; but the pores formed by the anasto- 

 mosing fibres are considerably large : it is whitish when divid- 

 ed, and its lace-like appearance, when examined by a lens, ren- 

 ders it a beautiful object : the pores or interstices of the fibres 

 are circular, and it frequently happens that numerous small pores 

 surround a large one : and in most cases the intervals between 

 the larger are filled up with smaller pores. The fibres are smooth, 

 and destitute of any fimbriae or detached unconnected parts." 



After a comparison of many specimens, I have been brought 

 to believe that the Spongia limbata and S. lobata of Montagu 

 are the same species, — the one in its primary, the other in its 

 old and mature condition. The latter he thus describes ; — 

 " With clustered ovate divarications^ — " The texture of this 

 sponge is rather more coarse than that of oculata ; the lobes 

 vary from ovate to oblong, and originate from an ill-defined 

 stalk in an irregular manner ; they are nearly connected, some- 

 times inosculate, and are furnished with a few prominent pores 

 without order. Colour yellowish-brown ; height two inches. — 

 Devou coast ; rare," 



