Bryo%oa. 



63 



from the latter with such massive colonies as those from the 

 Crags, which owing to their size have to he placed in the wall-case 

 (No. 12a), to realize that the Bryozoa were then living under more 

 favourable conditions. In fact, the Arctic Ocean was probably cut 

 off by a land barrier to the north, while there must have been 

 free communication with the seas to the south. The collection 

 in the Museum from this period contains the specimens used by 

 Busk as the types of his monograph on the ** Crag Polyzoa." 



The most interesting forms found in the Crag are some massive 

 Cyclostomata, including the three species known as Alveolaria 

 semiovata, Fascicularia aurantium, and F. tuhipora. Among the 

 Cheilostomata, the most remarkable forms are two species of 

 Cellaria (syn. Salicornaria) and one of Melicerita. The numerous 

 species of SchizoporellUy Mucronella, and Memhranipora are closely 

 allied to or identical with living forms. 



Bryozoa. 



GALLERY 

 VIII. 



Centre - 

 cases 



86a & 86b, 

 Wall-case 

 12a. 



Fig. 106. — Omjchocella Jiahelli- Fig. 107- — Membranipora jurassica, Gire^. 

 /or??zis, Lamx., sp. Bathonian: Bathonian : France. 



France. 



A small collection of Pleistocene species from the Clyde and 

 from Nelsea Bill is exhibited; but all these species still live on 

 the English Coast. 



The foreign Bryozoa are exhibited in Wall- case 12a; but the Wall- case 

 collection is not yet arranged, and only a few representative 

 species are exhibited. The lowest slope is devoted to the Palaeozoic 

 faunas, chief of which is that from the Silurian rocks of North 



12a. 



