BEEEKCCEA. 
91 
DlilEXSIOXS. 
Distance of apertures of 
same longitudinal series 
Diameter of zooecia 
Diameter of apertures . . . 
French 
Cenomanian 
D ’ Orbigny’ s type specimens 
{fide Pergens). [fide Canu). 
— ... •21--28mm. ... 
... •12 mm. ... '20^ 
... -04 „ ... — 
B.M. 
D.3886. 
•2-’4 mm. 
•15--2 „ 
•06--08 „ 
Disteibtjtiojt. 
British : 
Upper Chalk: S.E. of England. 
Middle Chalk : Chatham. 
? Bed Chalk : Hunstanton. 
Foreign : 
Turonian : Strehlen, Saxony, in Upper Planer ; Villardin, Loir-et-Cher. 
Cenomanian : Le Mans, Janieres, and St. Calais, Sarthe ; Yillers, 
Calvados ; lie Madame, Charente-Inferieure ; Havre and 
Cap de la Heve, Seine - Inferieure ; Plauen and Strehlen, 
Saxony, in Lower Planer; Kank, Bohemia, in Korycaner 
Schichten; El-Aiei’cha, Tunis. 
Figtjee. 
PI. YII. Fig. 8. A young typical zoarium, X 10 dia. Turonian: 
Yillardin Station, from Craie marneuse. D. 4593. 
Affinities. 
By its rather thick, flahelliform zoarium, with short, irregularly 
distributed zooecia, this ‘species’ is allied to B. Uttoralis (Orb.) ; 
from this form it differs by the smaller diameter of its zooecia, 
which are more closely packed. In these characters it resembles 
B. papillosa (Ess.), which has the zooecia rather more regular in 
distribution, while the zoarium is discoid and thinner. 
Some forms of B. regularis (Orb.) resemble B. gracilis (Edw.) 
in the shape of the zoarium and the distribution of the central 
zooecia ; but the two species differ by the crowding of the lateral 
zooecia in B. regularis. The species differs from the B. papillosa, 
form grandis, by the more uniform distribution of the apertures 
and the flahelliform shape of the zoarium. 
^ M. Canu remarks: “mes mesures sont identiques a celles de Pergens” 
(Bry. St. Cal. : Bull. Soc. geol. Fr. ser. 3, vol. xxv. p. 473) ; but in the only 
comparable dimensions given by those authors the measurement quoted by 
M. Canu is 66 % above that of M. Pergens. 
