82 the president's address. 



Fig. 25. Primitive tetraxon (calthrops) of Dercitopsis ceylonica, 

 x 230. 

 26a-26c. Small oxea of Dercitopsis ceylonica, x 230. (Oxea 

 four or five times as large occur in the same 

 sponge.) 



(Figs. 2-186, 20, 25-26c, from Dendy's Report on the Sponges 

 collected by Prof. Herdman at Ceylon in 1902. Figs. 19, 21, 22, 

 22a, 24, 24a, from Ridley and Dendy's Report on the Challertgo 

 Monaxonida. Figs. 23, 23a, from Dendy in Ann. <& Mag. Nat. 

 Hist., Ser. 5, vol. 20, PI. xv.) 



Journ. Quekett Microscopical Club, Ser. 2, Vol. XII., No. 72, April 1913. 



