Vol. 50.] MR. F. CHAPMAN OS THE BARGATE BEDS OF SURREY. 689 



There are some worn specimens of this species (from the clay of 

 the Bargate Pebble-beds at Littleton) which, on careful examination, 

 show some faint reticulations of the test-surface, but are otherwise 

 more typical of the species than those mentioned below. It is a 

 common species in Upper Cretaceous strata. 



Three valves only were found. 



3. Cythereis ornatissima (Reuss), var. reticulata, Jones & Hinde. 



Mon. Cret. Entom. Suppl., Pal. Soc. (1890) p. 24, pi. i. figs. 67, 

 68, 77 ; pi. iv. figs. 9-12. 



'The only specimen found is less than one-half the average 

 length of the specimens recorded in the Cretaceous Monograph, 

 this being only -J~ in. ('42 mm.) in length. It is a characteristic 

 Upper Cretaceous variety. 



Prom clay of Bargate Pebble-beds, Littleton. 



4. Cythereis Lonsdaleana, Jones. 



Mon. Cret. Entom. Suppl., Pal. Soc. (1890) p. 27, pi. i. figs. 40- 

 42, 64-66. 



This is a well-known form in Upper Chalk strata, and is also 

 recorded from the Upper Oolite of Ridgeway, Dorset. 



One valve from clay of Bargate Pebble-beds, Littleton. 



5. Cytheridea retorrida, Jones & Sherborn. 



Proc. Bath. N. H. & Antiq. F.-Club, vol. vi. (1888) no. 3, 

 p. 260, pi. i. fig. 8 a-c. 



This species was first described from the Fuller's-Earth clay of 

 Midford, near Bath. 



Pour valves from clay of Bargate Pebble-beds, Littleton. 



6. Cytheridea subpereorata, Jones. 



Quart. Journ. Geol. Soc. vol. xl. (1884) pp. 768 & 772, 

 pi. xxxiv. figs. 25, 26. 



The Bargate specimens agree in all particulars with the descrip- 

 tion and figures of the above species, which was first found in the 

 junction-bed of the Oolite and Neocomian (?), and also in the Great 

 Oolite, of the Richmond Well-boring in Surrey. 



One valve from clay-seams in Bargate Pebble-beds, Littleton ; 

 and one from the Pebble-beds in the lane leading to Great Halfpenny 

 Earm, below St. Martha's Chapel, Chilworth. 



7. Citheridea rottjndata, Chapman & Sherborn. 

 Geol. Mag. (1893) p. 349, pi. xiv. fig. 11. 



A solitary and fragmentary valve was found in the clay of the 

 Bargate series at Littleton, which possesses the peculiarly coarse 

 pittings on the surface of the test shown in the Gault specimen. 



