80 SPONGILLA LOEDII. 



from their root-hold to the water-level, a length of 

 two feet, and often more. This spongilla Professor 

 Bowerbank has kindly described for rne since my 

 return. I cannot do better than append the 

 Professor's description : 



1 SPONGILLA LORDIL (BOWEKBANK, N. S.) 



* Sponge sessile ; coating surface even, smooth ; oscula simple, 

 dispersed. Pores inconspicuous ; dermal membrane pellucid, aspi- 

 culous; skeleton specula, acerate. Ovaries congregated on the 

 basal membrane, very numerous ; specula entirely spined, fusiform, 

 cylindrical, dispersed on the surface. Basal membrane abundantly 

 spiculous ; specula dispersed same as those of the ovaries. Colour 

 ochreous, yellow to green. Examined in the dried state. 



' The sponge embraces the stems of a large 

 species of reed for eight or ten inches of its 

 length, and is about six or nine lines in greatest 

 thickness. In its general habit, and the struc- 

 ture of its skeleton, it closely resembles our J$ri- 

 tishFluviatilis; but it differs from that species in 

 the mode of disposition and structural peculiari- 

 ties of the ovaries, which more closely resemble 

 those of our British species S. lacustris, but 

 from which it differs in having the specula of 

 the ovaries nearly straight, while those of the 

 last-named species are usually arcuate. The 

 dermal membrane of S. lacustris also abounds in 

 entirely- spined tension specula, while that of S. 

 Lordii is aspiculous. 



