120 GUIDE TO THE FOSSIL INVEETEBEATE ANIMALS. 



Gallery 

 VIII. 



Case A5, 

 West Side. 



Case A5, 

 West Side. 



Wall-ease 

 12a. 



interesting and elegant Cryptostomes, such as Ptilodidya 

 suhlanceolata, Penniretepora Loiisdalei, and several species of 

 Fcnestella and PolyiJora. 



The Devonian fauna is small, and its representatives 

 not well preserved ; a specimen of Fenestella prisca, figured 

 by Phillips, and a Polypora populata are worth notice. 



The Carboniferous Bryozoa, on the other hand, are 

 numerous and show their structure well. The commonest 

 genus is Fmestella, and the size to which its colonies may 

 attain is exemplified by two specimens mounted on blocks. 



a b 

 Fig. 65. — Ciieilostomatous Bryozoa, from the Bathonian (Calcaire a poly- 

 piers) of Normandy, a, Membranipora jurassica, portion of a colony ; 

 in front of the large chamber-openings are in some cases small 

 depressions left by avicularia, in others round openings leading into 

 egg-pouches. Enlarged 13 diameters, b, Onychocella flabelliformis, 

 portion of a colony ; on the right is a chamber much narrower, than 

 the others, indicating that the individual was turned into an 

 avicularium. Enlarged 24 diameters. (From J. W. Gregory.) 



Case A5. The fan-shaped species of this genus and of Ptilopora, the 

 feather-shaped Penniretepora, and the cylindrical Rhombopora, 

 are the most interesting forms in the British Case. Hemi- 

 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 Fenestella. All the genera 

 Case A4. just mentioned are Cryptostomes. The adjacent case contains 

 a selection from the Carboniferous Bryozoa collected by 

 Mr. Gr. W. Shrubsole, mostly from Halkin Mountain in North 

 Wales. 



The Permian species are few; but three larger masses 



Case A5, 

 West Side. 

 Wall-ease 

 12a. 



