222 Mr. H. B. Brady on a 



XXXI. — 0)1 a true Carhoniferous NummuUte. 

 By Heney B. Beady, F.L.S., F.G.S. 



[Plate XII.] 



Theee are few time-marks in tlie geological record that have 

 been regarded as better established or more definite than the 

 first appearance of the Nummulite at or near the commence- 

 ment of the Tertiary epoch ; and any indications of an earlier 

 history which would throw back the origin of this well-known 

 genus to a Mesozoic or Palteozoic age can hardly be without 

 interest to the student of those genealogical problems, the bases 

 of which are found in the revelations of palseontology. 



Dr. Carpenter, in his ' Introduction to the Study of the 

 Foraminifera ' (p. 276), says, "there is no fact in palaeonto- 

 logy more striking than the sudden and enormous development 

 of the Nummulitic type in the early part of the Tertiary pe- 

 riod and its almost equally sudden diminution, bordering on 

 complete extinction. The precise position of the immense 

 beds of ' Nummulitic limestone,' the vast geographical extent 

 of which has been already sketched, has been a subject of much 

 discussion ; but the researches of M. d'Archiac, Sir R. Mur- 

 chison. Sir Charles Lyell, and others leave no further doubt 

 that these beds belong to the earlier part of the Tertiary period, 

 and that they correspond in position with the ' Calcaire Gros- 

 sier ' of the Paris basin, and with the ' Bracklesham ' and 

 * Bagshot ' beds of the London and Hampshire basins, in which 

 deposits alone are Nummulites found in the British Islands. 

 Although Nummulites have been described as existing at 

 periods anterior to this, it seems probable that such descrip- 

 tions have been founded on the occurrence of other helicoid 

 Foraminifera bearing an incomplete resemblance to them." 



The late Professor von Reuss, in his 'Entwurf einer systema- 

 tischen Zusammenstellung der Foraminiferen'*, is scarcely less 

 emphatic. He gives the distribution of the genus Nummulites 

 as follows : — " Fossil (Tertiary, especially Eocene). N. anti- 



* Sitzungsb. k. k. Akad. "Wissen. Wien (1861), vol. xliv. p. 391. 



It is not the object of the present paper to demonstrate the continu- 

 ance of the genus through the later Tertiary to recent times ; but, lest I 

 should be supposed to agree with the latter part of this qiiotation, I may 

 just state that, as far back as 1803, Fichtel and Moll figured two recent 

 Nummulites from the Red Sea, under the names of Nautilus radiattis and 

 iV; venosus (Test. Micr. p. 59, pi. 8) ; and Messrs. Parker and Jones, in their 

 essay on Fichtel and Moll's contributions to the Nomenclature of the 

 Foraminifera, published a year or more before the above passage from 

 Von Reuss, not only set this fact in a clear light, but instanced speci- 

 mens in their collection of true recent Ku7nmuIw<T from Davis's Straits 

 and from the Australian coi'al-reefs. I can only add that my own cabinet 

 presents confirmatory evidence in abundance. 



