BEKEXICEA. 
103 
The nearest Cainozoic ally of this species is B. fiabellum (Kss.) ^ 
from the Hungarian Leithakalk ; the zoarial characters are the 
same, hut the peristomes of the Tertiary form are lower, more 
regularly distributed, and more crowded. The resemblance of 
B. jessoni to the young of the Jurassic B. dilnviana, Lamx., is 
illustrated by comparison of Figures 2 and 3 on PI. Y. 
LIST OF SPECIMENS. 
D. 2964. A zoarium encrusting a fragment of Exogyra. Upper Greensand. 
Cambridge. Jesson CoU. Figd. PI. V. Fig. 3. 
D. 2025. On Terehratula bipUcata. Eed Chalk. Hunstanton. Jesson Coll. 
The type of Proboscina jessoni, Vine, 1890: Quart. Journ. Geol. 
Soc. vol. xlvi. p. 471, No. 15, pi. xix. fig. 7. A young zoarium. 
? D. 2986. Two young zoaria of doubtful identification (on slide). Upper 
Greensand. Cambridge. Jesson Coll. 
B. 4455. A zoarium. Upper Greensand. Cambridge. The type of Eiastoporci 
cretacea, var. lineata, Vine. Figd. : Proc. Yorks. Geol. Soc. 
yol. ix. pi. ii. fig. 8. 
9a. Berenicea jessoni (Vine), var. reniformis, nov. 
V'aeietal Chaeacteks. 
Zoarium reniform, and very thin. 
Zooecia small and thin, with highly raised peristomes, which are 
scattered somewhat irregularly. 
Gonocysts small ; elongate transversely. 
Dimensions. 
Length of zooecia '6 mm. 
Diameter of zooecia ... ... ... ... ‘09 ,, 
Diameter of aperture ‘06 ,, 
Distetbution. 
Middle Chalk : Chatham. 
Figtjkes. 
PI. YII. Fig. 6. A zoarium with two gonocysts on a fragment 
of Inoceramus, Middle Chalk : Chatham. Gamble Coll. D. 4153. 
1 Biastopora fiabellum, von Eeuss. Foss. Polyp. Wien. Tert. : Naturw. Abh. 
vol. ii. p. 51, pi. vii. fig. 9. 
