262 FAMILY NUMMULINIDA. 



instances (f^ 64, 119, 143), without any essential departure from the characters of the 

 respective types in which it occurs. 



450. Geof/raphical a/ul Geolor/ical Disfributioti. — The statements already made regarding 

 the geographical diffusion of Amphistegina apply equally well to Operculina, except that the 

 dwarfed forms of the latter have a much wider geographical range, being found in European 

 seas, and even within the Arctic circle. It is only between or near the tropics, however, that 

 this type attains its characteristic development. — The earliest recognised appearance of Oper- 

 culina in geological time is in the Cretaceous series ; it seems to have become abundant at 

 the commencement of the Eocene period, numerous forms having been described from the 

 early Tertiaries of England, Continental Europe, and Asia ; and it is traceable throughout 

 the whole series of Tertiary formations, specimens of no inconsiderable dimensions being 

 found in the Crag of Sufiblk. 



Genus III. — Nummulina (Plate XVIII). 



451. History. — Among all the diversified types presented by Foraminifera, there is none 

 which has either so long or so generally attracted the attention of Naturalists as that which 

 is now familiarly known under the designation Ninmnilife. And this is easily accounted for, 

 on the one hand by the comparatively gigantic size which it usually attains, on the other by 

 the enormous aggregations of individuals which constitute, with some intermixture of other 

 t)^es of animal life, a stratum of limestone not unfrequently attaining a thickness of 1500 

 feet, which extends in an east and west direction through Southern Europe, Lybia and 

 Egypt, and Asia Minor, and is continued through the Himalayan range of Southern Asia into 

 various parts of the great Indian Peninsula, where it acquires a very extensive development. 

 It is of this Umestone that the Pyramids arc partly built ; and it is in relation to those struc- 

 tures that we find the first-recorded mention of Nummulitcs. Putting aside the question 

 whether they are the bodies referred to by Herodotus and Pliny, it seems indubitable that they 

 attracted the notice of Strabo, who adverted to the local traditions that they were the petri- 

 fied remains of the lentils employed by the workmen as food, and remarked that this was 

 improbable, since in his own locality (Amasia, of Pontus in Asia Minor) there existed a hill 

 prolonged into the middle of a plain, the stone of which is filled with similar lentil-like bodies, 

 — a statement which has been recently confirmed by M. de TchihatcheS", who has brought from 

 that locality a beautiful series of Nummulites. The first examples of this type noticed in 

 Europe seem to have been those of the neighbourhood of Paris, which were described by 

 Agricola and Conrad Gesner, the latter of whom regarded them as a kind of Cornu Ammonis. 

 Aldrovandus adverted to them as " freaks of nature ;" Kircher, who seems to have formed 

 his notion of them from the vertical sections often produced by fracture, compared them to 

 willow-leaves; while Clusius, who designates them "numismales lapides Transylvaniap," 

 refers to the popular belief of the Transylvanians that they were pieces of money turned into 

 stone by King Ladislaus, in order to prevent his soldiers from stopping to collect them just 

 when they were putting the Tartars to flight ! 



