The marine Carboniferous of North-east Greenl. and its Bracliiopod Fauna. 547 



isms, partly not rolled. The rolled fragments are, too, more various 

 in size, than is the case in N:o 11'2, while the rock in 178 b is 

 re-crystallized in a less degree than in 112. Among the fossils ob- 

 served in the slide, the foraminifera are most numerously represented, 

 with some few specimens of Fusulinœ and Bigenerina, with numer- 

 ous rotaliform species; there are also seen some few crinoid stem- 

 joints and fragments of bryozoa. Of larger fossils, N:o 178 b con- 

 tains a badly preserved Euomphalus ; N:o 179 Spirifer cfr. striatas 

 Martin, and a Productus of the semireticulatus group, and N:o 170 

 a similar Prodactus. 



A similar rock is found in N:o 209 which, megascopically, and 

 in part, entirely agrees with those just described above, but has 

 undergone more thorough re-crystallization, and has smaller cavities 

 containing crystals of calcite. It also presents layers of a finer 

 crystalline rock which, even under the pocket-lens, appears to be 

 quite dense in structure. On a microscopic examination it proves 

 to agree perfectly with N:o 112, the matrix consisting entirely of 

 crystalline calcite, in which lie imbedded numerous rolled fragments, 

 although the size of these latter differs from that in N:o 112. While, 

 in some parts of the rock in question this size can amount to as 

 much as that in N:o 112, viz., 1 — 2 mm., it is in other parts con- 

 siderably less, or from 0.05—0.20 mm., these small grains, too, being, 

 in general, altered to crystalline calcite, while the larger retain their 

 original organic structure as fragments of Fusulinœ, crinoid stem- 

 joints, or other organisms. The process of re-crystallization the rock 

 has undergone does not seem to have been accompanied by any 

 dolomitising or silicification. 



Of larger fossils the boulder contains two well preserved spe- 

 cimens of Spiriferina Mylii n. sp. and a couple of specimens of 

 Schwagerina princeps Moll., together with several specimens of a 

 long Fusulina. 



A rock, which, at first sight, appears to be fairly different from 

 those mentioned above but which is probably connected with them, 

 is N:o 169, a light gray-red mottled rock which, in its darker por- 

 tions, contains small lighter coloured "pebbles" resembling those 

 observed in N:o 112 and the rocks agreeing with the one last-named. 

 Under the microscope the rock in question presents a structure 

 perfectly analogous to that of N:o 112, but it seems to contain, in 

 addition to well-rounded fragments, large angular pieces of another, 

 almost dense limestone, embedded in the crystalline matrix of cal- 

 cite. In this rock there occur, as in N:o 209, finer calcareous part- 

 icles, about 0.1 mm. in size, strewn among the coarser particles. 

 The red colour in the rock is, probably, mainly due to the fact 



