120 (UTIDE TO THE FOSSIL INYERTEBKATE ANIMALS. 
Gallery 
VIII. 
Case A5, 
West Side. 
Case A5, 
West Side. 
Case A5, 
West Side. 
Wall-case 
I 2 a. 
Case A5. 
Amei'ican rocks of tlio .siiine age. “Most of them are Trepo- 
stome.s or Cryptostomes, 
The Silurian Ihyozoa are in a better state, and the 
specimens from the Wenlock Limestone include some 
interesting and elegant Crypto.stomes, such as rtilodidya 
suhlanc.eolata, I’ennii'cfcpora Lonsdalci, and several species of 
Faiestdla and Volypora. 
The Devonian fauna is small, and its representatives 
not well preserved ; a specimen of Fcncslclla j^dsca, iigured 
hy Phillip.s, and a Folypora ijojndata are worth notice. 
a h 
Fig. G5. — Clieilostomatous Bryozoa, from cretaceous rocks. Enlarged 24 
diameters, a, Membranipora sp., from the Senonian (zone|ofiflHcm.sA>r 
cor-angtiinnm) of Oxfordshire, portion of a colony; in front of the 
large chamber-openings are in some eases small depressions left 
by avicularia, in others round openings leading into egg-pouches. 
h, Onychocella pyriformis, from the Maestricht Limestone, portion of 
a colony; on the right is a chamber much narrower than the others, 
indicating that the individual was turned into an avicularium. 
The Carboniferous Bryozoa, on the other hand, are 
numerous and show their structure well. The commonest 
genus is Feiicstella, and the size to which its colonies may 
attain is exemplified by two specimens mounted on blocks. 
The fan-shaped species of this genus and of Ptilopora, the 
feather-shaped rcnnirctepora,ViVi^ the cylindrical 72/ioTO&r/po?’«, 
are the most interesting forms in the Briti.sh Case. Hcmi- 
trypa should not be overlooked, as it consists of a colony 
formed of two layers, of which the upper was once regarded as 
a coral growing as a parasite on a Fcncstella. All the genera 
just mentioned are Cryptostomes. 
