true Carboniferous NummuUte. 225 



regular, lenticular, convex bodies 5 to 7 millimetres (5- to ^ 

 inch) in diameter and 1 to 1^ millim. (-23- to -^V inch) in 

 thickness, margin obtusely rounded rather than sharp, sur- 

 face polished and without visible perforations ; some speci- 

 mens not quite flat, but twisted. A section parallel to the 

 surface shows six or seven rather broad convolutions, each con- 

 sisting of numerous segments, the primordial chamber being 

 large, and the spiral widest near the centre. The tubulation 

 of the shell is most distinct at its thickest part. 



Another Nummuline fossil of Upper Jm-assic age, from 

 JMosskirch in Baden, is partially described in the same paper. 

 This is stated to be similar in size to the foregoing, but 

 distinguished from it by its numerous convolutions of equal 

 size and its much larger primordial chamber. The specimens, 

 which are in the Baden Geological Collection, appear to be 

 too imperfect to admit of more accurate description. 



Summary. — Accepting Dr. Gilmbel's facts and, in the main, 

 his analysis of the labours of previous authors, the scattered 

 record of evidence as to the appearance of the Nummulite at 

 periods anterior to the commencement of the Tertiary epoch 

 may be summed up, in a few words, as follows : — 



So far as relates to the Cretaceous system, some of the 

 reported specimens are not Nummulites at all, and there is 

 reason to doubt the geological origin of those Avhich are*. 



With respect to the Jm'assic epoch, Buvignier probably, and 

 Dr. Giimbel certainly, have obtained veritable members of the 

 genus from undoubted Oolitic beds. 



Lastly, although the researches of Rouillier and D'Eichwakl 

 on the fossils of the white limestones of Russia indicate a 

 a possibility of the existence of the Nummulite in rocks of 

 Carboniferous age, their figures and descriptions are such as 

 no subsequent author has been able to accept as definite or 

 entirely reliable evidence on the subject. 



NUMMULINA PBISTINA, nOV. sp. 



Introductory, — At the British Association Meeting in 



* Prof.Zeuschner(Verliandl.Russ.-kai.serl. min. Gesellschaft, St. Peters- 

 burg, Jahrg. 1847, p. 105 ) mentions the occurrence of Nummulites in large 

 numbers in a dolomite of Neocomian age immediately overlying Liassic 

 beds in the Carpathian Mountains. The paper is mainly geological, and 

 the fossils are not minutely described ; but the Nummuline character of 

 the organisms in question is apparently sanctioned and approved by Von 

 Keyserling in a short paper at p. 17 of the same volume. Keference to the 

 notices of Lower Cretaceous Nummulites would be incomplete without 

 some allusion to Zeuschner's memoir, although the evidence it nll'ords 

 may not be deemed conclusive ; and it may have been omitted by Dr. 

 Giiinbel on this account. 



