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LETTER XI L 



NUMMULITES DISCORBIS ROTALITES LENTICULINA L1TU- 



OLA SPIROLINA MILIOLA REN U LIN A GYROGONITES. 



LXXXII. Nummulites. A lenticular univalve, with an internal, 

 discoidal, multilocular spire, divided into numerous chambers by trans- 

 verse imperforated septa, and covered by several plates; the paries of 

 each turn being complicated, extended, and united on each side to the 

 other disks. 



The extreme obscurity in which the nature of these bodies has been 

 involved, almost to the present day, has occasioned the adoption of 

 numerous vague and even absurd conjectures respecting their origin. 

 By some they have been supposed to be the sports of nature, and by 

 others, seeds, the leaves of trees, and even pieces of money, miraculously 

 converted to stone. A variety of terms have been employed to designate 

 these substances. Thus, they have been named Helicitcs, from their 

 spiral structure ; Phacites, from their resemblance to a lentil ; and Sali* 

 cites, from the supposed resemblance of their sections to the leaf of the 

 willow. Pliny is supposed to refer to this body, under the name of 

 Daphniasi when he mentions that Zoroaster employed these substances 

 in the cure of epilepsy. From their substance and external form, they 

 have also been termed Lentes lapidea ; and from the appearances dis- 

 played by their sections, Lapides cumini, frumentarii, &c. 



Scheuchzer was the first who concluded that these bodies ought to be 

 ranked among the mineralized remains of animals, which had lived before 



