Mr. H. J. Carter on Ramulina parasitica, 95 



from a base about 1-1 200th inch in diameter, apparently 

 situated in the centre of a polygonal grain of calcite about 

 2-6000ths inch in diameter (fig. 3, a and b). Grains of calcite 

 forming in apposition the structure of the chamber-wall, 

 which is therefore very thin (fig. 4, a). Internally filled with 

 a reticulated structure (fig. 4, b, and fig. 5, a) , the larger inter- 

 stices of which are in many instances occupied by a spherical cell 

 (? reproductive body) (fig. 6, g &c.) varying under 4-6000ths 

 inch in diameter. In the confined state parasitically extending 

 into the cells of Orbitolites Mantelli, var. Theobaldi, which it 

 infests, when each lobe or chamber of the parasite occupies a 

 single cell in the central plane of this Orbitolite and is succes- 

 sively connected with its neighbours, chain-like, by a single 

 stolon (fig. 1, c, and fig. 6, h), while instead of following the 

 circular linear arrangement of the cells of the Orbitolite, the 

 chain-like development frequently leaves it obliquely in a 

 zigzag form (fig. l,e) ; or in the free state (fig. l,ff) spread- 

 ing out independently in the reticulated one above mentioned 

 among the sand &c. of the stratum in which the Orbitolites 

 have been deposited, now more or less held together by a 

 matrix of crystalline calcite, which in the polished fragment 

 admits of the Ramulina in its free state being seen at differ- 

 ent depths below the surface. 



Loc. The bed of Orbitolites Mantelli^ var. Theobaldi, in 

 the west bank of the Irrawadi, 6 miles below Thayetmyo, in 

 Burma (' Annals,' 18S8, voh ii. p. 342). 



Obs. This microscopic form so prevails in the bed of the 

 Orbitolites just mentioned, that it is hardly possible to subject 

 a small fragment of the latter, which has been polished for an 

 opaque object or ground down to a thin translucent slice, to 

 microscopic examination without observing several portions of 

 it ; while its chief habitat appears to have been in and about the 

 cells of the test of this species of Orbitolite, which is the only 

 species of large Foraminifera in the deposit. So like is the 

 chamber with its straight tubuli to the cells and their inter- 

 uniting tubuli, of which the ci'ust of the Orbitolite is com- 

 posed, except that the tubuli in the former are only on one 

 side, that it is often difiicult to distinguish the difference ; 

 but that it is a distinct structure is confirmed by its growth 

 in parts only of the central plane, as above mentioned, and 

 its occurrence over part of the " crust " in the microscopic 

 section of the " crust " and central plane together, where the 

 contrast between the two is unmistakable. Of course all 

 that is peculiar to it noio in a lapidified state must have 

 taken place before it thus became perpetuated by fossilization. 

 Although parasitic it was evidently a species of Foramini- 



