386 Zoological Society : — 



always attached to marine bodies, and the cellular body of the animal 

 being strengthened with spicula and enclosed in a calcareous cell fur- 

 nished with a single contracted aperture and pierced with numerous 

 foramens or tubes. 



These shelly bodies differ from all the shells of Rhizopods hitherto 

 known, in being attached, and in the form, structure, and disposi- 

 tion of the cells, which (should the existence of spicula on the body 

 prove a peculiarity of the genus Carpentaria, where alone it has 

 been observed) is sufficient to form a group distinct from the other 

 Rhizopods. 



The existence of these spicula shows that the genus Carpentaria, 

 and probably all the group, forms the passage between the Porifera 

 and Rhizopods, which has been long suspected to exist, but has not 

 before been described. 



On the Mediterranean specimens of Cardita variegata there is 

 intermixed with the Dujardinia a species of Lepralia, the anoma- 

 lous Polytrema minaceum, consisting of numerous layers, one 

 deposited on the other, each formed of a calcareous network, with 

 small equal hexangular interspaces, and undefined patches of a 

 crust formed of rough calcareous cells placed side by side like the 

 cells of a Lepralia, but much more unequal in size and irregular in 

 form than the cells usually found in that genus. The parietes of 

 these cells are pierced with numerous equal-sized minute pores like 

 the foramens of Foraminifera, the whole substance of the cell being 

 apparently formed of numerous short shelly tubes placed parallel 

 side by side. The cells are furnished with a small roundish hole at 

 one of their extremities, which is often hid by the convexity of the 

 other cell. 



This may be a peculiar genus of Lepraliadce allied to my genus 

 Cribrillina (Cat. Brit. Radiata, pp. 116, 147), which has "forami- 

 niferous cells," as Professor Busk calls them ; or it may prove to be 

 another form of Foraminifera. If the former, the form of the cells 

 and mouth, and the structure of the cell-walls, are sufficient to 

 distinguish it from Cribrillina. As the only way to draw attention 

 to it is to give it a name, I propose to form for it provisionally, 

 until its nature is better understood, a genus named 



PUSTULARIA. 



Cells ovate, four- or five-angled, convex, crowded together side 

 by side, forming a crust without any definite form ; the cells closed, 

 their entire parietes being pierced with numerous close uniform mi- 

 nute pores ; the cavity simple ; aperture small, roundish, simple at 

 the front end of the cell (without any ovarial cells ?). 



1. PUSTULARIA ROSEA. 



The crust rose- red, rather rugose. 

 Hab. Mediterranean. 



