96 



INTRODUCTOllY OBSERVATIONS. 



cells and surmounted by a circle of tentacles, and their ovicap- 

 sulcs rising from the componnd body, and external to the indi- 

 vidual — all follow the zoophytic type. It is not till we examine 

 their internal structure that their affinity to the Mollusca becomes 

 apparent. Btit admitting their near alliance with the Tunicata, 

 it may be asked, Do the Radiata form a sub-ldngdom really dis- 

 tinct from the Mollusca? When the process of development is 

 better understood in the separate groups, it may possibly be 

 found that there are in reality only three grand types of structure 

 in the Animal Kingdom — the Artlculata^ the Mollusca^ and the 

 Vertehrata; the radiated forms being only lower stages of the 

 two former — the Echinoclermata going to the Artkidata, with 

 which they have many alliances, and the Zoopliyta to the Mol- 

 lusca. Such speculations, however, do not belong to my present 

 humble labours. The business of the compiler of a provincial 

 Catalogue is not to form systems, but to discriminate species, 

 and to classify them in a way that may best facilitate their study. 

 Too little is known of the local distribution of zoophytes in 

 the British seas to enable us to make any complete or satisfac- 

 factory comparison of this with other localities. On the whole, 

 the species of this class appear to be much more generally dif- 

 fused, and to occupy a wider range, than is the case with most 

 other classes of marine Invertebrata. The following species may 

 be taken as characteristic of our north-eastern shores : — 

 Eudendrium rameum. 



„ confertum. 



Tubularia Dumortierii. 

 Halecium muricatum. 

 Sertularia tricuspidata. 



,, fallax. 



„ filicula. 



,, fusca. 



Tliuiaria thuia. 

 Plumularia Catherina. 

 „ frutescens. 



Grammaria ramosa. 

 Pennatula phosphorea. 



Actinia digitata. 

 Anthea Tuedia?. 

 Gemellaria loriculata. 

 Celepora Skenei. 

 Bugula fastigiata. 



„ Murray ana. 

 Flustra truncata. 

 Carbasea papyrea. 

 Eschara cribraria. 

 Retepora Beaniana. 

 Alcyonidiuni mammillatum. 

 Farrella pedicellata. 

 Avenella fusca. 



