MULTIZONOPORA. 
223 
Fig. 60, Part of the surface of a zoarium of var. suhnodosa, 
showing one band with only mesopores ; X 10 dia. I!^eocomian : 
Berklin gen. D. 3652. 
Fig. 61. Part of a section across the same specimen; 
X 10 dia. Xeocomian : Berklingen. D. 3652. 
Affinities. 
The first difficulty with this species is due to the fact that 
Koch & Bunker’s figure does not show the zonal arrangement of 
the apertures and mesopores. That their species was dimorphic 
is evident from their description, ‘‘ poris creberrimis majoribus et 
minutissimis.” Homer promptly referred a zonal form to this 
species, and he has been followed by later authors. That this 
course is correct is most probable, as some of the Museum specimens 
show the zonal structure only in parts of the zoarium, and even 
in these places very imperfectly (as in D. 7087), though in others 
it is quite distinct. 
Multizonopora arborea, var, subnodosa. 
Fig. 60. — Part of surface of zoarium ; x 10. D. 3652. 
Fig. 61. — Transverse section ; x 10. D. 3652. 
Examination of the specimen D. 3650 has led me to the view 
that the Pustulopora hiformis of Eomer is a synonym of this 
species. Homer's fig. 20c shows a well-marked zonal arrangement 
