182 
vine: polyzoa of the wenlock shales. 
As some authors''' have expressed an opinion that possibly Cheilos- 
tomatous species existed in paloeozoic times, I have placed a (?) 
rather than affirm dogmatically that the sub-order did not exist. In 
Messrs. Young's paper on carboniferous species of Polyzoa,! the 
authors refer to a sub-oral pore in Glauconome stellipora, Young and 
Young remarking that as the smaller opening " cannot be regarded 
as that of the ovicell, the only other structure to which it can be 
compared is an avicularian appendage, and if this view be correct, 
some at least of the palaeozoic polyzoa would belong to the (sub) 
order Cheilostomata, thus adding another to the list of persistent 
ordinal types." Mr. Ulrich. however, in his scheme of classification^ 
adds the following — " sub-order Cheilostomata, Busk, Fam. Mem- 
braniporidse, Busk . . . ? Paleschara, Hall. Zoarium incrusting; tubes 
very sliort. Cell apertures direct, angular, and more or less oblong. 
Cincinnati to Lower Helderberg." And recently Mr. A. W. Waters |i 
remarks, in his paper on Fossil Cyclostomatous Bryozoa from Australia, 
" Among the palaeozoic fossils there is in one or two a structure 
which may represent the suboral pore or avicularium, and so long as 
we do not know the signification of the adventitious tubules ofDiasto- 
pora obelia, we may be justified in asking if they may not possibly 
have had an homologous origin." 
Sub-order, Cyclostomata, Busk. 
Cyclostomata Busk, Brit. Mus., Cal. pt. iii. : Crag Polyzoa ; 
Hincks, British Marine Polyzoa, p. 416. 
Tubuliporina, Milne Edwards. 
Auloporina, Myrioporina, (part) Ehrenberg. 
Cerioporina, (part) Bronn. 
Centrifuginea, (part) D'Orbigny. 
Zorecia tubular, with a plain inoperculate orifice (normal), or 
with closure § (Waters). Marsupia and appendicular organs (avicul- 
aria and vibricula) wanting. 
* Messrs. Young- of G-lasgow, aud Mr. Ulrioh of America. 
tQaart. Journ. Geol. Soc, Dec. 1874, p. 683 
J Ciucin. Soc. Nat. History (Journal) Oct. 1832, p. 157. 
II Qaar. Journ. Geol. Soc. Vol. 40, p. 675. 
§ See paper on the " Closure of Cyclostomatous Bryozja," J oar. Linn. Soc, Vol, 
xvii. p. 400, &c., pi. xvij. 
