204 Mr. R. B. Newton on Fossil Mollmca dec. 



lie recognized in the rocks of Northern Italy (Viceiitin), and 

 which were stated to range geologically from the Lower 

 Eocene to Aquitanian *, their maximuni sixii being reached 

 in the latter horizon. This record was, however, nnacconi- 

 panied by a description, figure, or reference to specific forms, 

 and so failed to have any scientific importance from the 

 nomenclature point of view. 



In the same memoir Mnnier-Chalmas notified that he hat! 

 previously alluded to tliis generic name in the Bull. Soc. 

 (J^ol. France, 1891, s^r. 3, vol. xix., but without giving the 

 pagination. A careful perusal of tlie volume has proved the 

 inaccuracy of such a statement, no mention of Orthophrag- 

 viina being found ; so that it can oidy be surmised that the 

 author had in prepaiation a paper upon the subject whicii 

 a])parently never saw publication. 



Later on Schlumberger j, who had been studying the 

 structure of Orbitoides, commenced to issue a series of papers 

 in which the genus Orthophragmina was adopted, with 

 Orbitoides pratti as the type, this being the equivalent of 

 O rhitoli tes pi'atti, MicheVm (see references in footnote, 1901, 

 p. 464, and 1903, p. 274), originally described from the 

 supra-Cretaceous beds of the environs of Biarritz, France. 



Giimbell had previously regarded Michelin^s pratti as 

 synonymous with JS'ummulites ^yfip^t'oceus of Boubee (Bull. 

 Soc. G^ol. France, 1832, vol. ii. p. 445), which he placed 

 under the genus Orbitoides, as well as recognizing it as the 

 type of his subgenus Discocyclina. 



Later researches have demonstrated that the structures of 

 these two species are not the same, Schlumberger deteimining 

 l^oub(^e's papgraceus as a true Orbitoides and restricted 

 to Upper Cretaceous deposits. Hence it would appear that 



* An Aquitanian example was not then mentioned specifically, al- 

 thou"-li said to occur in " les calcaires d'lsola di Malo " (see p. 19 of the 

 Thesis). Later on in the same work (p. 76) this form was referred to as 

 Orthophru(jmina {Orbitoides) elephantma, a species wliich was subse- 

 quently described and figured by .Messrs. Lemoine and K. DouvilltS (M(5m. 

 Soc. Geol. France, 1904, vol. xii. fasc. 2, Mem. no. 32, pi. ii. tigs. 13, 19, 

 p. 13) as a Lepidoci/clina, and not Orthophr(i(jniina. The genua Ortho- 

 phraijmina is therefore essentially Eocene, being found as high as the 

 Priabonian stage, which is regarded alike as uppermost Eocene or the 

 lowest part of the Oligoceue. It does not occur in a later horizon. 



t Bull. Soc. U(5ol. France, 1901, ser. 4, vol. i. pi. vii. pp. 459-467 

 (Cretaceous) ; it)id. 1902, ser. 4, vol. ii. pi. vi. pp. 255-261 (Cretaceous) ; 

 ibid. 1903, ser. 4, vol. iii. pis. viii.-xii. pp. 273-289 (Eocene) ; ibid. 1904, 

 s^r. 4, vol. iv. pis. iii.-vi. pp. 119-135 (Eocene). 



t Ibid. p. 112. 



