262 Geological Society. 



black streaks ; palpi white towards base ; pectus, legs, and ventral 

 surface of abdomen white, the femora and tibiae tinged with brown, 

 the fore tibiae with blackish band at extremity. Fore wing grey 

 tinged with brown ; a slightly curved blackish antemedial line ; a 

 narrow black discoidal lunule ; postmedial line blackish, slightly 

 bent outwards and waved from vein 5 from above 2, then retracted 

 to below angle of cell and slightly sinuous to inner margin ; cilia 

 whitish tinged with brown and with a blackish line at base. Hind 

 wing grey tinged with brown ; an oblique black discoidal bar ; 

 postmedial line blackish, bent inwards and almost obsolete on 

 vein 2, then Soblique to tornus ; cilia whitish tinged with brown 

 and with a blackish line at base. Underside white, the fore wing 

 tinged with brown except on inner area. 



Ilab. Peru, La Mercede, Chanchamayo {Watkins), 1 S type. 

 Exp. 32 mm. 



[To be continued.] 



PROCEEDINGS OF LEARNED SOCIETIES. 



GEOLOGICAL SOCIETY. 



December 5th, 1917.— Dr. Alfred Harker, F.R.S., President, 

 in the Chair. 



A Demonstration on the Application of X-Rays to the 

 Determination of the Interior Structure of Micro- 

 scopic Fossils, particularly with reference to the 

 Dimorphism of the Nummulites, was given by E. Heron- 

 Allen, F.L.S., F.G.S., Pres.R.M.S., and J. E. Barnard, F.R.M.S. 



Mr. Heron- Allen said that in the year 1826 Alcide d'Orbigny 

 published among the innumerable, and for many years unidentified, 

 nomina nuda that compose his ' Tableau Methodique de la Classe 

 Cephalopodes ' the name Rotalia dubia. This species was left 

 untouched by Parker & Jones in their remarkable series of 

 articles ' On the Nomenclature of the Foraminifera.' The French 

 naturalist G. Berthelin was the first investigator to unearth and 

 make use of the ' Planches inedites ' which had been partly 

 completed by d'Orbigny for the illustration of his great work upon 

 the Foraminifera, a work that was never published. Working 

 with Parker & Jones's paper, Berthelin made for his own use 

 careful tracings of 246 of A. d'Orbigny's unfinished outline- 

 sketches. These sketches were never elaborated by d'Orbigny upon 

 the ' Planches,' which are still preserved in the Laboratoire de 

 Paleontologie under the care of Prof. Marcellin Boule; among them 

 was found the sketch of Rotalia (labia. On the death of Berthelin 

 the tracings passed into the possession of Prof. Carlo Fornasini 

 of Bologna, who reproduced them all in a valuable series of papers 

 published between the years 1898 and 1908. Fornasini's opinion 



