ELEID^. 
291 
The Serdiyisiox of the Eleid^, 
As d’Orbiguy recognized, we have among tlic Eleidce a series of 
Brvozoa with very different habits. Some are adiiate discs like 
Berenieea ; others, erect fronds like Biastopora ; and others, solid 
cylindrical shoots like Entalopliora. But as the group is small, 
there is no need to subdivide it into two families corresponding 
to the ])iastoporidae and Entalophoridae. 
D’Orbigny based his primary division into genera with large 
‘ cellules ovariennes ’ and those without. This arrangement is 
unsatisfactory, as has been pointed out by Pergens, who seems, 
however, to liave unnecessarily reduced the number of genera. 
Nodelea is a convenient group if d’Orbigny’s definition be emended, 
and the genus be retained for Elcids with erect, solid branched 
zoana and without avicularia. Meliceritites may then be accepted 
for species with a similar habit, but provided with avicularia. 
The i)resence or absence of avicularia is, however, not easy to 
])rove ill fragmentary specimens, because the avicularia are often 
sparsely scattered. But to treat this character as of generic value 
is hardly to give it undue importance, since it has hitherto been 
regarded as of ordinal value. 
The Xatuke of the C'EmyE. 
AVe have seen that in the Eleidoe the zooocia expand distally, 
and contract proximally to a thin, narrow tube, generally with 
thick walls. If we remove from an Eloid the thin front walls, 
and thus expose the expanded ends of the zooocia, there is left 
a specimen with the surface formed of thin raised walls which 
enclose hexagonal or lozenge-shaped cavities, at the bottom of each 
of which is pore opening to a narrow tube. This is exactly 
the structure of the specimens for which d’Orbigny instituted 
the family Ceidae. Take, for example, Filicea regularise Orb. 
(Bit. Cret. pi. 786, figs. 1-4). The two sections shown by 
d’Orbigny arc both essentially the same as in Meliceritites. The 
figure of what is represented as the external surface shows a series 
of hexagonal cells, each of which is continued downward as a fine 
tube. AVhat is described as the aperture is the upper end of 
the narrow proximal portions of the zooecia, where they open out 
to the distal expansion. 
Hence the family of the Ceidm must be dismembered among 
