BEEEXICEA. 
101 
PL YI. Pig. 1. Middle Chalk : Chatham. Half a worn zoariiim 
with well-marked peripheral, crowded zone ; x Id dia. Tine 
Coll. D. 960. 
Afftnities. 
This species is characterized by its thick, circular zoariiim, with 
the apertures crowded round the margin. It is the Cretaceous 
representative of Berenicea verrucosa (Edw.), from which it differs 
by the greater elevation of the distal ends of the zooecia and the 
greater thickness of the zoarium. In these respects it resembles 
B. arcJiiaci (Haime) ; but it has not the well-developed gonocysts, 
and the peristomes are more crowded than in that form. 
According to Tine’s description his Biastopora cretacea has 
a zoarium with a central depression and a thickened edge, and 
may thus belong to this form; but the type-specimen is missing 
from his collection, so that the question cannot be definitely 
decided. 
Among Cainozoic species the nearest to B. pohj stoma is 
B. echinulata (llss.),^ which has an even thicker and more crowded 
zoarium. 
LIST OF SPECIMEXS. 
D. 2987. Two zoaria (on slide). Middle Chalk. Chatham. Tine Coll. 
One IS figured on PL Y. Fig. 5. 
D. 960. A worn zoarium an an echinid fragment. Middle Chalk. Chatham. 
Tine Coll. Eecorded as JJiastopora congesta, Orb., by Tine : 
Eep. Erit. Assoc. 1892, p. 329. Figd. PL YI. Fig. 1. 
9: Berenicea jessoni (Tine), 1890. 
Synonymy. 
Proboscina jessoni, 1890. Bry. Red Chalk: Quart. Journ. Geol. Soc. 
vol. xlvi. p. 471, pi. xix. fig. 7. 
,, ,, Yine, 1891. Polyz. Bed Chalk : Proc. Yorks. Geol. Soc. 
vol. xi. p. 376. 
Biastopora cretacea, var. lineata, Yine, 1885. Camhr. Greensd. : ibid. vol. ix. 
p. 18, pi. ii. fig. 8. 
' Biastopora echinulata, von Eeuss. Foss. Polyp. Wien. Tert. : Xaturw. 
Ahh. vol. ii. p. 50, pi. vii. fig. 6. 
