534 H. B. Brady — Fossil Foram'mifera of Sumatra. 



that the larger specimens are often rather umbonate. It will be seen, 

 therefore, that there is no distinction, of even varietal force, to be 

 drawn between the two ; and they correspond sufficiently closely 

 with the description and figures of N. variolaria given by MM. 

 D'Archiac and Haime. It is needless to enter into detailed examina- 

 tion of any species which has been treated by the authors referred 

 to in their exhaustive way, or indeed to do more than observe, in 

 general terms, that the form under consideration is one of the 

 "radiate" group, 1 comprising the small and relatively thick modifi- 

 cations of Nummulina planulata, common in the early Tertiaries of 

 Western Europe. 



Locality — Coralline Limestone of Nias Island. 



3. Nummulina Bamondi, Defrance. PI. XIII. Figs. 4, a, b. 

 Nummulites Bamondi, Defrance, 1825, Diet, des Sci. nat. vol. xxv. 



p. 224. 

 Nummulites Bamondi, D'Archiac et Haime, 1853, Descript. Anim. 



foss. Groupe numm. de l'lnde, p. 128, pi. 7, figs. 13-17. 



To this species may safely be assigned a small number of some- 

 what obscure radiato-striate Nummulites from Nias Island, one of 

 which is represented in PI. XIII. Figs. 4, a, b. The largest specimen 

 has a diameter of ^inch (3"0 mm.), and is about — inch (1-2 mm.) in 

 thickness. It has been difficult to arrive at any exact information 

 as to the interior structure of the specimens, as in all of those of 

 which microscopical sections have been attempted, not only the 

 minute anatomy of the shell, but even the septation, was greatly 

 obscured by subcrystalline infiltration. None of those examined 

 had more than about six convolutions, the outermost formed of about 

 fifty chambers — being therefore somewhat smaller than the dimen- 

 sions of N. Bamondi as set clown by Messrs. D'Archiac and Haime, 

 that is, so far as the examples sent to us are representative — but in 

 all important characters they correspond fairly with the description 

 and figures of the French monograph. Externally they are radiato- 

 striate ; in the horizontal section the spiral wall is much thicker 

 than the septal lines ; the number of chambers corresponds suffi- 

 ciently closely, though the number of convolutions is not so great, 

 and the primordial chamber is, as far as can be made out, relatively 

 small. The specimen figured shows considerable want of symmetry 

 in its peripheral aspect, the two sides being of unequal convexity, 

 a rather unusual feature in Nummulina. This form is not far re- 

 moved zoologically from the Bornean specimens which Heer Verbeek 

 has described under the name Num. Pengaronensis, 2 and which are 

 rightly supposed by him to be near allies of N. Bamondi; but we find 

 nothing in the material at our command to suggest the necessity of 

 separating the Sumatran examples from the latter species. 



Few of the Nummulites have a wider distribution than this ; from 

 the south-west of France, eastwards through Central Europe, 



1 See Arm. Nat. Hist. ser. 3, vol. v. p. 110, and viii. p. 231. 



2 Neues Jakrbucli fur Min., etc., Jahrgang 1871, p. 3, pi. 1, figs. 1, a-k. 



