﻿68 



CARBONIFEROUS AND PERMIAN EORAMINIFERA. 



1 or 3, but more complete examination shows that the resemblance is that of analogy, 

 rather than of relationship. The arenaceous exterior of Bigenerina (as of Textularia 

 generally) is the result of sandy incrustation on a normally perforate shell-wall ; the shell 

 in that genus is regularly and neatly built, and the aperture takes the form of a single, 

 rounded, central, terminal orifice. These are more important peculiarities than the mere 

 order of the segments. On the other hand, the thick, finely arenaceous tests of the 

 specimens under consideration, their irregular septation, labyrinthic chambers and com- 

 pound apertures, are characters that necessarily give them a place amongst the Lituolida. 

 In many particulars they bear considerable resemblance to varieties of the genus Haplo- 

 phragmiwm figured by Reuss, 1 but the absence of the regular, depressed, spiral arrange- 

 ment in the earlier chambers would, of itself, preclude their being associated with the 

 typical members of that group ; and observations especially on young and on monstrous 

 specimens seem to indicate that these obscure Carboniferous forms are allied to Valvulina 

 rather than to Lituola proper or Haplophragmium. In some young examples the earlier 

 portion of the test, possibly at first the whole organism, is almost conical, and divergence 

 from the Valvuli?ta-\[ke mode of growth begins in an uneven or oblique setting on of 

 chambers. But the conical aspect of this part of the test is lost as the Textularian habit 

 is subsequently developed. On the whole it seems clear that such forms could not with 

 propriety be assigned to any previously recognised genus. 



Climacammina antiqua, Brady, PI. II, figs. 1 — 9. 



Textularia antiqua (Brady, MS.), Young and Armstrong, 1871. Trans. Geol. Soc. 



Glasgow, vol. iii, Suppl., p. 13. 

 Climacammina antiqua, Brady, 1873. Mem. Geol. Survey Scotland, Expl. Sheet 23, 



p. 94. 



Characters. — Test elongate ; subcylindrical, compressed or spathulate, unsym- 

 metrical, sometimes curved at its commencement. Earlier chambers irregularly biserial 

 or subspiral ; later ones uniserial, often set on obliquely. Septation imperfect ; sutures 

 marked externally by depressed lines. Segments numerous, more or less ventricose 

 externally ; interior subdivided or labyrinthic. Shell-texture compact, firmly arenaceous. 

 Aperture formed of several irregular orifices on the face of the terminal segment. 

 Length ^5- to ^ of an inch (1*0 to 2-5 mm.) or more. 



A large number of specimens, presenting amongst them a wide range of variation in 



1 See especially Haplophraymium irreyulare and //. cequale in the memoir on the Foraminifera of 

 the Chalk of Westphalia (' Sitzungsb. k. Akad. Wissensch. Wien,' 18G0, vol. xl, p. 74, pi. x, fig. 9, and 

 pi. xi, figs. 2, 3). 



