4 8 



Memoirs of the Indian Museum. 



[Voi,. V, 



are often actually stouter than those of greatest length. The breadth of the head is 

 slightly greater than that of the shaft. The measurements of the spicules are 

 extremely variable both individually and in different sponges, but some of them are 

 always much larger than any in L. aquae- dulcior is. 



Gemmules are produced in large numbers. They are formed in groups at the 

 base of the sponge and are visible externally as relatively large patches of lichenoid 

 outline and of a deep orange-yellow colour. The skeleton becomes completely dis- 

 organized in these patches and the basal membrane disappears as an independent 

 structure. Each group consists of numerous gemmules piled one on the top of the 

 other several layers thick. The individual gemmules are flattened on the lower sur- 



Fig. ii. — Laxosuberites lacustris, sp. iiov. 

 A. — Larva in optical section, x 255. 



The cilia are omitted. 

 B. — Vertical section though a mass of gemmules, x 30. 



face, distinctly convex above, and polygonal in outline. The whole mass (fig. iib) 

 is fixed together by spicules of the normal type which transfix the coats of the gem- 

 mules vertically or tangentially, their heads being lower than their tips. The actual 

 reproductive body consists of a congeries of cells of the usual form gorged with 

 globules of food-material of a bright yellow colour. It is to this substance that 

 the colour of the whole mass is mainly due, but it is intensified by the tint of the 

 horny coat. Each gemmule has its own coat, but the different gemmules of one 

 patch are so closely pressed together that their coats become intimately connected. 



