On Cycloloculina. 533 



c.cm. 



Coarse sittings left on the 3 V m - sieve . . . . 22-5 



Pure Foraminifera (skimmed froni the surface) .. 5 - 



Floatings left on the gL-in. sieve .. .. .. 24 -5 



.. ,, ^-in. silk 9-5 



Elutriated material left on the 3 V m - sieve .. 6-0 



ffVin. sieve •• 63- ° 



T^-in. silk .. 15-5 



Residue .. .. .. .. .. .. 854-0 



1000-0 



Within a year of the incipience of the task of examining the 

 material, I had compiled a catalogue of over 200 species, both 

 recent and fossil, but very soon upon the query slide I found 

 I had three or four discoidal shells of a highly friable nature, 

 in very imperfect condition, that I had never seen before. I sub- 

 mitted them to my collaborator in this paper, who recognised as a 

 fact, what I had by that time tentatively advanced, viz. that the 

 shell was, at any rate, a new species, perhaps related to the 

 Planorbulina costellata or flabellum of Terquem.* 



Once, however, mounted in balsam, we recognised that we were 

 dealing with a Foraminifer, not only new as regards species, but 

 having an entirely new plan of growth and development, and con- 

 sequently a new genus. The determination and description of the 

 shell is as follows : 



Precis of Origin. 



The specimens on which the genus is founded are fossils, and 

 were found in company with many other fossil Foraminifera derived 

 from Secondary and Tertiary strata. A large proportion of the 

 fossils are such as would occur in Tertiary beds of the period of 

 the " Calcaire Grossier " (Eocene), and it is therefore probable that 

 the specimens have their origin in the submarine denudation of 

 strata which are not exposed above low-water mark. It is hoped 

 to settle this point by dredging in the neighbourhood, but in the 

 meantime it is thought desirable to publish this description of the 

 most interesting form yet met with in the gatherings. 



Family IX. Rotaliidae. 



Sub-family 2, Eotalin^e. 



Genus, Cycloloculina Heron-Allen and Earland. 



Definition of the Genus. — Test free (or perhaps sometimes 

 adherent in the later- stage of growth), complanate, discoidal, con- 



* Les Foraminiferes de l'Eocene des Environs de Paris. By M. O. Terquem, 

 Mem. Soc. Geol. de France, ser. 3, ii. (1882). 



