182 CALCAEEOTJS SPOXGES. 



This species is very abundant at Farringdon ; the examples are usually larger than 

 the forms from the Cenomanian at Essen*. 



Distribution. Lower Green Sand : Farringdon, Berkshire. Cenomanian = Upper 

 Green Sand : Essen, Rhenish Prussia. 



CORTNELLA TETEAGONA, Goldf. sp. 



1826-33. Scyphia tetragona, Golclf. Petref. 1 Th. p. 4, t. 2. f. 2. 



1826-33. Scyphia mamillaris , Goldf. Petref. 1 Th. p. 4, t. 2. f. 1. 



1864. Endostoma tetrayonum, F. A. Roemer, Pal. Bd. 13, p. 39, t. 14. f. 7. 



1871. Epitheles tetragona, Gein. Pal. Bd. 20, p. 33, t. 8. f. 9-12. 



1878. Scyphia tetragona, Quenst. Petref. Bd. 5, p. 352, t. 132. f. 13, 14. 



1878. Corynella tetragona, Zitt. Studien, III Ab. p. 37. 



1883. Corynella tetragona, Duuik. Pal. Bd. 29, p. 36, t. 39. f. 1, 2. 



Distribution. Cenomanian: Essen, Rhenish Prussia. 



CoRYifELLA KUGOSA, HincU. (Plate XXXIV. figs. 10, 10 a.) 



1882. Corynella rugosa, lliude, Ann. & Mag. Nat. Hist. ser. 5, vol. x. p. 196, t. 10. f. 4, 

 and t. 11. f. 25. 



Sponges simple, cylindrical, straight or curved, growing from a slender base ; the 

 summits truncate. The outer surface has concentric ridges and furrows, or tubercular 

 elevations. An average example is 48 mm. in height and 18 mm. in thickness. The 

 walls are from 4 to 7 mm. in thickness, and the tubular cloaca is 4 mm. wide at its 

 summit. 



The outer surface exhibits closely arranged, approximately circular pores formed 

 by the interspaces of the fibre. The fibres are about "22 mm. in Avidth, and are 

 composed of slender filiform three-rayed spicules, closely disposed parallel with each 

 other in the direction of the fibre. The outer surface is furnislied with a dermal 

 layer of larger four-rayed spicules. The spicular structure of this species closely 

 resembles that of Tremacgstia D'Orbigni, H. 



Distribution. Upper Green Sand : Warminster, Wiltshire {coll. Cunningtoa). 



* The sponges from Essen, figured by Quenstedt under C. foraminosa (Petref. Bd. .5, p. 351, t. 132. 

 f. S-10), differ very materially from the typical examples of this species, and in fact resemble more nearly 

 some forms of Elasmostoma than Corynella. They are either simple or eompouud, subcyliudrical or funnel- 

 shaped ; the interior surface is smooth and minutely cribrate, with circular, well-defined, closely approximate 

 apertures about '6 mm. in width. The exterior surface is partially covered with a dermal layer ; where this 

 is not present, the naked fibres of the wall are exposed. Unfortunately the spicular structure is quite 

 destroyed in the thin section examined ; and therefore I propose to allow these forms to remain under Cory- 

 nella until their minute structure is determined, and to designate the species C? crihrata. 



