92 
OSCULIPORIDiE. 
Dimensions. 
B.M. D.395. 
PI. III. Fig. 1. 
B.M. D. 3959. 
PI. II. Fig. 7. 
Height of zoarium 
Diameter of branches ... 
Width of base 
Peristomal bundles : length 
1 mm. 
•9 M 
•9.n 
7 nam. 
1-1*5 „ 
, , , , width . 
Zooecia: diameter 
, , diameter of apertures 
Distribution. 
British : 
Chalk — Zone of Mici'aster cortestudinarium : Chatham. 
Figures. 
PI. III. Fig. 1 . Heverse face of the end of a branched zoarium ; 
X 8 dia. Middle Chalk — zone of Micraster cortestudinarium : 
Chatham. Gamble Coll. D. 395. 
PI. II. Fig. 7. A young worn -zoarium. Fig. la, the obverse 
face; X 6 dia. Fig. Ih, the obverse of the branch to the right 
and the reverse face of the longer branch; x 6 dia. Middle 
Chalk — zone of Micraster cortestudinarium : Chatham. Gamble 
Coll. D. 3959. 
PI. II. Fig. 8. A still younger zoarium. Fig. 8a, the obverse 
face; X 6 dia. Fig. 8 the reverse face; X 6 dia. Middle Chalk — 
zone of Micraster cortestudinarium : Chatham. Vine Coll. D. 689. 
Affinities. 
This species includes small zoaria, of which the reverse face has 
the aspect of Osculipora, as the zooecia on that surface are raised 
into ridges like the fasciculi of Osculipora. The obverse view, 
however, shows that the species is an ffomceosolen, as the apertures 
are distributed over the whole surface. 
The species is easily distinguished from M. ramulosus by the 
bushy form of the zoarium and the sub-branches being curved 
outward away from the main stem, and also by the Osculiporoid 
arrangement of the groups of apertures. 
Its nearest ally is H. tetragonus (d’Orb.) from the Cenomanian, 
which also has the Osculiporoid arrangement of the apertures in the 
lateral processes ; but in JS. tetragonus these apertures are in small 
subcircular groups and not in narrow bands. (Cf. d’Orbigny^ 
pi. 796, fig. 11, with Cat. PL III. Fig. 1.) 
