Manchester Memoirs, Vol. Ixii. (191 7) 5 



calcite, and is probably due to structural differences. For 

 fuller information I must refer my readers to the original 

 paper. 



To the best of my information very little has been written 

 of the Foraminifera of the Blue Marl, and only the larger forms 

 are recorded. Philippe de la Harpe has written five papers on 

 the Nummulites of Biarritz which were published in the 

 ''Bulletin de la Societe de Borda a Dax" during the years 1879 

 to 1881. Eighteen species are noted in those works, of which 

 number six were found in the Blue Marl of the Cote des 

 Basques. My search has been rewarded by nine (?) species, 

 five of which do not appear in M. de la Harpe's list. In 1873 

 M. le Comte R. de Bouille published at Pau a work entitled 

 "Paleontologie de Biarritz et de quelques autres localites des. 

 Basses-Pyrenees." In the list of fossils in this work are men- 

 tioned as being found in the Blue Marl two species of 

 Operculina, five of Orbitoides, and three of Nummulites. (We 

 have reproduced Halkyard's notes on this work in Appendix A. 

 H-A. & E.) In Prof. T. Rupert Jones' "Catalogue of the Fossil 

 Foraminifera in the Collection of the British Museum" there 

 is mention made of many specimens of Nummulites, Orbitoides, 

 and Operculina from Biarritz, some of which are marked 

 "Middle Beds", and others though not so marked are evidently 

 from the lower hard beds of the same series. These "Middle 

 Beds" are the ones now under consideration. 



The works by the above-mentioned authors are the only 

 ones of any importance which I have come across dealing in 

 any way with the Foraminifera of Biarritz. (See, however, our 

 Introductory Observations, H-A. & E.) 



Before proceeding to describe the species of Foraminifera 

 in my collections, I desire to take this opportunity of recording 

 my indebtedness to Mr. F. Chapman, A.L.S., F.R.M.S., to 

 whom my best thanks are due for his kind assistance in the 

 determination of critical species. I also have to thank Mr. 

 F. W. Millett for his ready response to my appeals for his help. 



In order to avoid an unnecessary addition to tne length of 

 this paper, I have only given two references to figures of each 

 species described, viz., one to the original figure and descrip- 

 tion, and the other (where possible) to that given by the late 

 Dr. H. B. Brady in his magnificent work on the Foraminifera 

 collected during the Challenger Expedition, which work I 

 believe the most generally accessible to all students of the 

 Foraminifera. 



