frovi the Carboniferous Limestone uf Devonshire. 159 



labyrinthic structure sliows a dark centre, more or less irre- 

 gular in shape, as if the crystallization or infiltration had begun 

 round the walls and had not quite filled up the centre of each 

 space. The whole of the arenaceous walls or framework is 

 rendered solid by the infiltration of the calcareous matter, so that 

 even the quartz grains require nitric acid of its full strength 

 to separate them. So far, I have not observed any shells of 

 Foraminifera or any extraneous material worked into the walls 

 of this species, more than the grains of quartz-sand ; and if 

 the calcareous matter were withdrawn, leaving only the arena- 

 ceous walls, the difference between a portion of this and Dr. 

 Carpenter's figure (t. 76. fig. 2) would be very little indeed. 



In some of the labyrinthiform spaces there may be observed, 

 besides the one dark irregular mark, two or three small specks 

 like imperfect cells : in one place I observed three elliptical 

 disks, with perfectly formed double rings or walls ; but al- 

 though these disks have at first sight the appearance of sec- 

 tions of corals, the annulations are only paler-coloured lines, 

 and not solid walls. The two loops in the left-hand figure and 

 the septa in the lower figure are all of the same kind (see 

 fig. 12); they do not appear ever to have been solid structures. 

 When I first saw these cells, I thought it probable that the 

 foraminiferous animal had grown up round some stems of 

 corals for support ; but on a more careful examination I am 

 compelled to give up this opinion. 



Now the question is, what is this animal, and what position 

 can we assign to it in the scale of creation ? It does not ap- 

 pear to be a Gliona ; or if it is, its habits are quite different 

 from those of other forms I am acquainted with ; nor does it 

 agree well with the arenaceous grouj) of sponges, the " Dys- 

 idea^^ so far as I know them ; but, viewing this in all its 

 bearings, it appears to me to hold a place between the arena- 

 ceous Sponges and the arenaceous Foraminifera. The stolo- 

 niferous growth is common to both ; in the Foraminifera there 

 appears to be a much greater degree of regularity observed in 

 building up their structures than is seen in the habits of the 

 stoloniferous Sponges. The general growth of the Foramini- 

 fera is more or less concentric, starting from a primordial cell ; 

 in the fossil we have imder consideration no such growth can 

 be traced, although no doubt this also sprang from a primordial 

 cell. But I would not insist upon this, as it may have been a 

 gemma or bud, or even a group of cells ; but whatever its 

 beginning may have been, it has spread over several inches 

 of the carboniferous limestone, and was also three or four 

 inches thick. There is not the least sign of its ever having 

 been circumscribed by a test of any kind, but it appears fo 



