FOEAMTNIFEBA OF THE FAMILY ASTEORHIZIDiE. 321 



Unfortunately there is not suificient material to submit the 

 structure of the sliell to more complete examination. 



The form therefore appears to be an extremely simple type of 

 Poraminifer, living attached to foreign bodies and building a 

 protective roof, but vrith that remarkable power of selecting 

 sponge-spicules for its building material which is shown in 

 Pilulina, Marsipella, and Technitella. 



In habit it is the equivalent of simple forms of Nubecularia 

 in the Porcellanea, and of Flacopsilina and Wehlina in the 

 Lituolidje. 



It may be objected that this spicular structure should not be 

 regarded as a character of generic value ; and that such a type 

 as Placopsilina bulla might, if circumstances compelled it to 

 build with spouge-spicules only, produce a similar shell. There 

 is, however, a great difference in the style of architecture of 

 forms that constantly select spicules and those that, as it were, 

 pick them up indiscriminately with sand and shell-fragments. 



In such a form as Saliphi/sema the shell may be entirely sandy 

 or completely spicular ; but as all intermediate stages occur, no 

 one would give separate names to the extreme forms. On the 

 other hand, the characteristic shape of Pilulina and Technitella, 

 combined with their constant spicular character, gives them an 

 undisputed title to generic distinctness. 



The case now under consideration seems to me to be a parallel 

 one : and in proposing a new generic name I am only following 

 the precedent of the late Dr. H. B. Brady. 



The tent-like shape and the spicular structure suggest the 

 name of HhapMdoscene. 



A possible alternative would be the revival of the name Squa- 

 mulina, first used by Schultze *. His specimens, however, seem 

 to have been only immature individuals of Nuhecularia ; and as 

 the best-known form referred to this genus, the so-called 8qua- 

 mulina scopula of Carter, turned out to be founded on the basal 

 dome of specimens of Haliphysema, it is better that the name 

 should be allowed to drop. 



EXPLANATION OF PLATE X. 



Bhaphidosceiie conica on Botellina labyrinihica. 



* Schultze, ' Ueber den Organismus der Polythalamien,' 1854. 



