GIRTY, NEW CARBONIFEROUS FOSSILS 301 



tabulfe are numerous, usually about a diameter apart, occasionally somewhat 

 less, more often somewhat more, rarely two diameters. They are centrally 

 perforated after the manner characteristic of this group. 



To this species I have also referred some specimens which occur associ- 

 ated with the types and agree with them in microscopic peculiarities, but 

 differ in being imiserial expansions, one side of which is covered by an 

 epitheca (?). The growth is very irregular and attains a thickness of 

 15 mm. or more, appearing to consist of several successive layers in some 

 cases. Sections through such specimens transverse to the zooecia show 

 the rather characteristic groups of mesopores with extra large zooecia 

 associated with them. The walls manifest great diversity in thickness, 

 being exceedingly thin in some areas and much thickened in others near- 

 by. Acanthopores are somewhat sparsely developed, but are very large, 

 strongly indenting the chambers when the walls are not too thick. In 

 some cases, where the thickness is very great, there seem to be a number 

 of grannies distributed along the median line instead of one large acan- 

 thopore situated at the angle. Sections cutting the walls longitudinally 

 show them to be thickened in the mature region and annulated, the annu- 

 lations being strong, abrupt and frequent. The diaphragms are rather 

 closely arranged, a diameter or less apart, but, in the younger region and 

 also near the outer surface, occasionally much more. The early prostrate 

 portion appears to be, in some cases at least, very long and very slender. 

 Owing to irregularities of growth, such areas of slender, non-tabulated 

 cells occasionally recur in the midst of the more mature conditions. In 

 some cases, if not all, the zooecia, after they leave the prostrate position 

 and are of more nearly mature size, are thin-walled and non-tabulate 

 for a longer or shorter distance, after which the annulations and tabulae 

 begin to appear. In the explanate specimens, the tabulae are sometimes 

 quite closely arranged over considerable areas, one half a cell diameter 

 apart, more or less. 



Coeloclemis subgeu. nov. 



Of this variety of structure, only one species is known and it is there- 

 fore taken as the type. It comprises small, irregular, hollow, dichoto- 

 mous branches lined with an epitheca. The zooecia are naturally short, 

 as the central cavity of the branches is large and the bounding zoarium 

 thin. They are prostrate and thin-walled in the immature portion, erect 

 and thick-walled in the mature. The amount of thickening varies much 

 from point to point, and it is regular and not moniliform. Maculge and 

 monticules are present, but are neither well marked, abundant nor regu- 

 larly arranged. Tabulae may be present (in the prostrate portion), but 



