Zoantharia — Corah. 



105 



Aporosa. Favosites is, however, often claimed by some authorities 

 to be an Alcyonarian. This class finds a better representative in 

 the chain-coral, a species of which {^Hahjsites catenularia) began in 

 the same period, and survived until much later. 



The Silurian corals in Table - cases 8 and 7 are in better 

 preservation than those of the Ordovician period, but the afRnities 

 of many are uncertain. In the first half of Table-case 8 there 

 are forms which are either Anthozoan or Alcyonarian, such 

 as Favosites. Some of the remaining specimens in the same half 

 of this table-case may be really Bryozoa — such are Favositella, 

 CoetiiteSf and Alveolites ; and others, such as Syringopora, are 

 either Alcyonaria allied to the Organ Pipe Coral or are Zoantharia 

 belonging to the order Perforata. 



Corals. 



GALLEBT 

 X. 



West Side. 

 Wall- 

 cases 15, 

 Table- 

 cases 1-8. 



Fig. 159. — A, a fragment of a colony of Syringolites Huronensis, Hinde (nat. 

 size) ; B, a single calice of the same, enlarged eight times, showing the 

 central tube and radiating lines of septal tubercles ; C, part of a corallite of 

 same, split open longitudinally and enlarged six times, showing the com- 

 position of the central tube out of the invaginated tabulae ; D, part of a 

 corallite of same, viewed from the exterior and enlarged six times, showing 

 the mural pores. Niagara Limestone (Silurian) : Manitoulin Island, Ontario, 

 N. America. 



On the opposite side of this table-case, are a series of forms 

 belonging to the genus Montieulipora and its allies Monotrypella, 

 Fistuli'pora, and Callopora, which, though left in this gallery for 

 the sake of convenience, ought properly to be transferred to the 

 Bryozoa. Adjoining this series are some fine specimens of a small 

 encrusting coral, Aulopora, which grows in an open network over 

 shells and corals ; also thick fronds of the aberrant genus Thecia, 

 massive growths of Heliolites (an ally of the Blue-coral Eeliopora\ 

 and some elegant specimens of the Dudley chain-coral, Halysitea 

 catenularia (Fig. 160). 



The Silurian Corals in Case 7 are of more certain affinities. 



