CLAUSA. 
421 
Hivlensions. 
Fide Pergens. 
B.M. B.M. 
D. 3089. D. 4555. 
Diameter of head 
— 
2-4 mm. ... 3*5 mm. 
Diameter of stem 
— 
•5 ,, ... 1-8 „ 
Length of stem 
— 
11 „ ... 18 „ 
Diameter of orifice 
... -18 mm. ... 
•1.5--2 ,, ... -2 „ 
Distribution. 
British : 
Upper Chalk : 
Bromley ; Croydon ; 
‘ Ludstou ’ (? Ludsdowu, west- 
south-west of Kochester). 
Middle Chalk : Chatham. 
Foreign : 
Senoniau — Maastrichtian ; Meudon ; Fecamp. 
Santoniau : Saintes, Charente. 
Turonian : Angoulcme, Charente; Saintc -Maure, Indi-e-et-Loire. 
Figures. 
PI. XVII. Fig. \a, a zoariiim of var. tenuicaulata, nat. size. 
Fig. IJ, the head of the same specimen. Fig. Ic, part of the stem 
of the same. Upper Chalk : Bromley. Bowerbank Coll. D. 3089. 
PI. XVII. Fig. 2a, a zoamim of var. crassicaulata, nat. size. 
Fig. 2h, the head of the same specimen, X 8 dia. Fig. 2c, part 
of the stem of the same, X 8 dia. Middle Chalk : Chatham. 
O amble Coll. D. 4555. 
PI. XYII. Fig. 3. Head of another zoarium, x 10 dia. Upper 
Chalk: S.E. England. Tonlmin Smith Coll. D. 4556. 
PI. XYII. Fig. 4. Part of another zoarium with highly raised 
peristomes, X 10 dia. Middle Chalk: Chatham. Gamble Coll. 
B. 4563. 
PI. XYII. Fig. 5. Part of a zoarium of var. erassicaulata, with 
a long free peristome; X 10 dia. Middle Chalk: Chatham. 
Gamble Coll. D. 4559. 
PI. XYII. Fig. 6. Base of a zoarium of var. elegans, x 6 dia. 
Middle Chalk : Chatham. Gamble Coll. D. 4100. 
PI. XYII. Figs. 8<?, h. The base of a zoarium, fr’om above and 
from the side. Fig. 8a, nat. size ; Fig. 85, x 2 cha. ^Middle 
Chalk : Chatham. Gamble Coll. D. 4197. 
PI. XYII. Fig. 10. A branch fr’om a zoarium of the fonn 
elegans, X 6 dia. Middle Chalk : Chatham. Yine Coll. D. 628. 
