308 



DR. G. P. BIDDER ON 



Fig. 1. 



K 



S 



L M 



Seals of fx . tffft 



Explanation of Text-figures. 



Figs. A-G are uniformly drawn to a multiplication of 1650 diameters to be comparable 



■with Dendy's plates ; figs. H-M are X 3000 diameters. Figs. B and H are after Dendy ; 



figs. I and K after Robertson. 



Figs. A-E. Syncrypta spongiarum : — (A and B), 4- and 8-celled stages from the flagellate 

 chambers of G. compressa ; (C), 16 (?)-celled, and (D), 32-celled stages from 

 the flagellate chamber of Clathrina clathrus ; (E), single monad in the collar- 

 cell of Q. compressa (the cell is very much contracted and distorted in 

 preservation). (A, E, Plymouth Dec. 14 ; C, D, Naples Jan. 8 ; B, H, Plymouth 

 Apr. 24.) 



Figs. F-G. Pylocytes : — (F), of 8. raphanus which had been fed with starch until cessation 

 of the current ; (G), of G. compressa (the collar-cells are in active division). 



Fig. H. The 16-celled stage of Syncrypta spongiarum enlarged, for comparison, from 

 Dendy's fig. 89. 



Figs. I-M. Ingestion of monads by collar-cells of Clathrinida? : — (I), "foreign body" 

 (Robertson and Minchin, fig. 48) in a collar of Guancha coriacea ; (K), 

 "enclosure,.... perhaps of a parasitic nature" (Robertson and Minchin, 

 fig. 35) in collar-cell of the same sponge ; (L), " chlorophyll granule P " 

 enclosed in a collar-cell of Ascaltis cerebrum ; (M), a pyrenoid enclosed in a 

 neighbouring collar-cell of the same sponge. 



