vine: classifications of cyclostomatous polyzoa. 
353 
VI. Theonoidse 23. Tlieonoa. 
24. Fascicularia. 
25. Lopholepis. 
26. Apsendesia. 
VII. Frondiporidie 27. Frondipora. 
28. Truucatula. 
29. Distichopora. 
30. Pletliopora. 
It is of no service whatever, to hide from the student the 
suggestion that the above grouping is anything but natural, when 
fossil species below the Crag are under consideration, or even certain 
species in the Crag. To a large extent the grouping is built up from 
partially facial characters, and I am not at all surprised to find 
Palsentologists offering suggestions, or making re-aiTangements of the 
family grouping. The family Cevioporidie is particularly obnoxious, 
for there is not the least affinity between the Spiropora of Haime, 
and the HderoiioreU-i of Busk. The type of the family Idmoneidae 
should have been, so far as I am able to judge, Ilmone'i, and not 
Hornera ; then the genus Terehellaria, as defined by Lamouroux and 
D'Orbigny, would find no resting-place here. If, however, we accept 
the genus as defined, and in all probability limited, by Haime, 
Terehellaria is a Diasl opera adhering to, and simulating the undula- 
tions or ramifications of the fossil organism to which it is attached, 
Cricopora and Spiroporu, in all probability, belong to the same 
group, yet one genus is placed in the Idmoneidae, and the other in 
the Cerioporidae — one, the cells distinct ; the other, the cells indis- 
tinct. 
Professor Smitt's arrangement of the Cyclostomata," — as already 
stated — is open to objections, but his grouping is by far the more 
natural ; and it must not be forgotten that Smitt treated of recent 
Cyclostomata only, whereas Busk endeavoured to grapple with recent 
and fossil species in one s}Tiopsis. Smitt arranged the Cyclostomata 
as follows : — 
Tribe, Infundibulata, Gervais. 
Order, Cyclostomata, Busk. 
* Krit. Fortneck. Ofver Skandinaviens Ilafs Bryozoer, 1864-65. 
