6 THE CANADIAN NATURALIST. [Vol. X. 



and it can scarcely be anytliiog else thau a RhizojDod, probably 

 allied to the modern Saccammina gJohosa, or to the Carboni- 

 ferous S. Carteri, though much smaller than either, and diflfering 

 in its tendency to external ornamentation. It is of course pos 

 sible that a test of this kind might belong to an animal of very 

 different character from Saccammina, but in the present state of 

 knowledge of such forms, I think it quite justifiable to refer it 

 to this genus." 



In the conclusion of the above note I referred to the chara- 

 like form of the test, and to its entire difference of structure-- 

 from any vegetable organism. At a subsequent date I obtained 

 additional specimens from Mr. Walker, of Hamilton, Ontario ;; 

 and in my paper on Stromatoporidce, published in the Journal 

 of the Geological Society in 1879, I referred to it, under the^ 

 above name, as associated with Stromatopora, and sometimes' 

 overgrown by its layers. 



In the course of last summer, I received from Prof. William- 

 son, of Manchester, Part X of "his valuable Memoirs on the- 

 Organisation of the Plants of the Coal Measures, and was sur- 

 prised to find my little fossil noticed therein, with a new name 

 and in quite a new connection. It appears that some bodies of 

 similar appearance, but much smaller, had been found by Prof. 

 Judd in Carboniferous limestone in Wales, and that they had* 

 been referred to the group of Radiol arians. This reference was- 

 disputed, apparently on good grounds, by Prof. Williamson. He- 

 had examined them, under the impression that they might be of 

 vegetable origin, but finally had supposed it more likely that 

 they were animal and foraminiferal, and had assigned to them 

 the non-committal name of Calcisphcera. They had also, in the 

 course of the discussion as to their nature, raised the chemical 

 question whether it was possible that silicious tests like those of 

 Radiolarians could be replaced by carbonate of lime : a change 

 which, though perfectly possible, and sometimes realised in Pa- 

 laeozoic silicious sponges, is in the highest degree improbable in 

 the case of these bodies. In the course of this investigation, 

 Prof. Williamson had received from our mutual friend Mr. H. B. 

 Brady, F.R.S., specimens of the little fossil from Kelly's Island? 

 which, I think, I had sent to him, and these were referred by 

 Williamson to the same genus with the Welsh specimens and 

 named by him Calcisphcera rohusta. He described the speciee 

 as follows ; 



