194 
HETEROPORIDiE. 
branches, which are generally in one plane. One variety 
(var. lohata) is massive with lobate blunt branches. In 
a third (var. cylindrica) the branches are cylindrical and 
project in all directions. 
Zooecia with medium-sized apertures ; mesopores in single 
circles around each aperture, but in places less numerous. 
Dimensions. 
Height of zoarium 
Von Reu^s’s types, 
mm. mm. 
32 2r> 
B.M. D. 7400. 
mm. 
60 
Width of zoarium ... 
18 30 
;')0 
Diameter of apertures 
— -15 
•1 -12 
Distance of zooecial centre.s 
— about *3 
•3--4 
Distribution. 
Exgland : 
Upper Greensand — Zone of SchJooibachia rostrafa : Haldon Hills. 
? Lower Greensand : Brickhill, Upware. 
Foreign : 
Cenomanian — Lower Uuader: neat Dresden, Saxony. 
Albian : Grandpre, Ardennes. 
Figures. 
PL YIII. Fig. 5. A zoarium of var. coalescens. Upper Green- 
sand — zone of Schloenhachia rostrata : Haldon. Fig. ba, the whole 
zoarium; nat. size. Fig. bh, part of the surface; X 10 dia. 
D. 7400. 
t 
PI. IX. Fig. 1. • A zoarium of var. lohata. Upper Greensand — 
zone of ScJdoenhachia rostrata : Haldon. Fig. \a, the whole 
zoarium; nat. size. Fig. \h, part of the surface; X 10 dia. 
D. 7399. 
PL IX. Fig. 2. A zoarium of var. cylindrica. Upper Green- 
sand — zone of Schloenhachia rostrata : Halddn. Fig. 2a, the 
zoarium from above ; nat. size. Fig. 2h, part of the surface ; 
X 10 dia. D. 7405. 
Affinities. 
In spite of the difference in form of these three varieties, they 
appear to be all members of one species. The zooecial arrangement 
agrees essentially with that of the type of von Eeuss, though the 
closeness of the zooecia varies in different specimens (cf. PI. IX. 
Figs. \h and 2h) and in different parts of the same specimen. 
