226 Dr. J. D. Macdonald on the Polycystina. 



particulars similar to that of the Foraminifera; but where this 

 is not tlic case, it is simply continuous or only augmentative. 

 Though our knowledge of the Polycystina is yet verv- limited, 

 the two modes of growth here indicated suggest their distri- 

 bution into two corresponding sections, thus : — 



Poli/ci/sfina. 

 Rhizopoda furnished with a siliceous spicular or fenestrated framework. 



continuous .. -j jj,,^,^,v/h.;». 

 concentric accessions 



Growth of (''^""l^^ 

 sarcode 1 j. 



j Sft/locIicfj/(i. 

 ) Asstromma. 



Now that the surface pelagic life of the Polycystina is a 

 matter of fact, avc can readily account for the occuiTcnce of so 

 many interesting forms in guano. 



Fisr. 1. 



FiiT. 2. 



•1; "S^--<..'■^'■' 



A.t(roi»f)i(i Yc/rcrfoni. 



Front -view. 



Side view. 



Figs. 1 & 2 are respectively a front and a side view of a 

 species oH Astronwta with three radiating lobes, A. An'stoteh's 

 having four. As the species appears to be new, I have named 

 it Astromma Yelvcrtoni. 



II.M.S. 'Lord Warden. 

 Corfu, June 24, 1^71. 



