66 G. E. ANDERSON 
between the two being such as might readily be expected of different 
individuals in the same species. This difference lies in the epithecal 
projections characteristic of Eridophyllum which are entirely want- 
ing in Craspedophyllum. It seems not unlikely, therefore, that a 
generic relationship exists between these types. If this be so, 
Craspedophyllum must be considered as the ancestor. This is 
further substantiated in 
the greater specialization 
of Eridophyllum ver- 
neuilanum when com- 
pared with Cras pedo phyl- 
lum subcaespitosum. 
Thus the Eridophyllum 
is more specialized in 
the early expansion to 
normal size; in the com- 
plete inner wall which 
appears earlier in the life 
of the individual; and in 
the additional feature of 
epithecal projections. If 
the relationship outlined 
proves true, it is evident 
Fic. 7 = Cross-section of mature specimen of that Erido phyllum ver- 
Craspedophyllum archiaci, showing the incom- neuilanum cannot be 
plete inner wall with the cardinal septum extend- genetically related to the 
ing into the inner central area. 
oe Hee ey 
Siluric species, Erido-— 
phyllum rugosum as the latter makes its appearance before the pos- 
tulated ancestor of Eridophyllum verneuilanum, i.e.,Craspedophyllum. 
The characters now relied on for generic distinction being homoeo- 
morphic, these would represent entirely distinct genera, and not as 
now generally considered, species of one genus. LEridophyllum rugo- 
sum requires further investigation, which is rendered very difficult 
as most material is silicified and the delicate internal structure 
destroyed. 
Other corals with true inner wall.—Hapsiphyllum (Simpson) and 
Laccophyllum (Simpson) both contain an inner wall; in the former it 
