VINE: BRITISH PALAEOZOIC CTENOSTOMATOUS POLYZOA. 75 
commit themselves to any definite opinion as to the systematic posi- 
tion of the fossils described, but they remarked (p. 467) " Our A. 
fusiforme . . . presents a close superficial resemblance to the 
creeping base of Anguinaria (iEtea) spatulata ; but in the absence 
of any evidence in the fossils of the existence of erect cells with dis- 
tinct apertures for the polypides, it would be hazardous to regard 
this suggestion as being more than a conjecture. The only other 
recent forms to which we can find any likeness with Ascodictyon are 
some of the Sertularians {e.g. IS. pumila), there being a decided 
resemblance between the thread-like fibres which creep along the 
foreign bodies to which these organisms are attached, and which 
connect the polypiferous shoots and the netted stolons of A. radians 
and A. stellatum. In other respects, however, the structure of Asco- 
dictyon is by no means Hydrozoal." 
In one of Mr. E. 0. Ulrich's earlier papers, amongst other 
descriptions of new genera and species of fossils from the Lower 
Silurian about Cincinnati,* the author founded a new genus, 
" Rhopalonaria," for the reception of an equally obscure organism 
encrusting Streptelasma comiculum, Hall. The species was placed 
in the family Crisidw. Mr. Ulrich says (op, cit., p. 27) "on account 
of the great delicacy of the fossil, the fronds themselves are rarely 
found, but instead we find a series of impressions on the exterior 
coat of the Streptelasma, which very well represents the fronds and 
cells of the same." I have in my possession an example of Mr. 
Ulrich's species, and I find that it is well described and figured in 
the work already referred to (p. 26). 
4. Rhopalonaria venosa, Ul. (op. cit., p. 26, pi. 7, figs. 24-24c.) 
When Dr. Nicholson's and Mr. R. Etheridge's paper was pub- 
lished, I was already in possession of fine examples of Scotch 
Carboniferous forms encrusting crinoid stems derived from the 
Hairmyres Shales ; later on these were added to, and just recently 
a very fine series of the Carboniforous forms from the Calderwood 
Shales have been given to me by Mr. John Young, so as to enable 
me to work out details which have been as yet only partially des- 
cribed. 
* Journ. Cincinnati Soc. Xat. Hist, vol. ii., p. 26. 
