200 REPORT—1883. 
respects these ‘club-like’. partitions resemble the ‘spiniform’ processes 
described as ‘ Spiniform Corallites ’' by Professor Nicholson, but they have 
nothing of the character, as will be presently seen, of corallite structure. 
On the surfaces of the zoariwm and in the transverse sections these bars are 
prominent characteristics of the Ptilodictya of the Wenlock series of rocks 
at least, and, in a modified form, the bars in the Sulcoretepora of the 
Carboniferous rocks closely resemble them, but in none of the sections of 
the Monticuliporide given by Nicholson, or made by myself, are there 
any structures with which I can compare them. They appear to me to 
be unique both in character and function; neither do they resemble any 
partitions known to me in Cyclostomatous Polyzoa, recent or fossil. 
V. Development of the zoarium of Ptilodictya. In one of Mr. Ulrich’s 
earlier papers,” the author describes and figures two remarkable and 
Fie. 3.—Ptilodictya Lonsdalei, Vine. 
1. Young specimen just above the base (section). 2. Section of young specimen, 
having eight rows of cells; two (a) central, and three (c, c) lateral on each side. 
d. ‘Non-poriferous margins.’ 
minute fossils, which he named Craferipora. In his paper on ‘ American 
Paleozoic Bryozoa’ (op. cit. p. 151) Mr. Ulrich refers to Crateripora as 
being the ‘attached bases of Ptilodictyonide.’ These Crateripora form 
expansions upon foreign bodies, in the centres of which are small cup-like 
depressions. They are, as Mr. Ulrich says, the bases or rootlike por- 
tions of Ptilodictya, and though not common in the Wenlock Shales, I 
have several of them in my possession. Sometimes they are found upon 
corals, sometimes upon the zoariwm of Ptilodictya itself; they are small 
disks, and at this early stage they have none of the after-characters of 
1 The Genus Monticulipora, p. 45. 
% Journal of the Cincinnati Soc. Nat. Hist. April, 1879. 
