80 TABULATE CORALS. 



the former in favour of the latter. It is not clear, however, 

 that any of the forms originally included by Hall (loc. cit.) under 

 the name Cladopora are really congeneric with Pachypora 

 lamellicornis, Lindst. ; while it is certain that many of the 

 forms which have subsequently been placed under Cladopora 

 by American palaeontologists are of very diverse affinities. 

 Moreover, Dr Rominger states that septa are not developed in 

 the forms which he calls Cladopora, these structures being un- 

 doubtedly present in the typical forms of Pachypora, Lindst. 

 Under these circumstances, therefore, I have not thought it 

 advisable to resuscitate the genus Cladopora, though it is quite 

 possible that one or more of the forms originally described 

 under this name by Hall are really identical in their characters 

 and structure with the more recently described Pachypora 

 of Lindstrom. 



So far as certainly known, the species of Pachypora are con- 

 fined to the Upper Silurian and Devonian deposits. 



Pachypora lamellicornis, Lindstrom. 

 (PI. IV., figs 2-2 c.) 



Pachypora lameUicornis, Lindstrom, Nagra anteckningar om Anthozoa Tabu- 



lata. Ofversigt af Kongl. Vetensk. Akad. Forhandl., 1873. 

 lamellicornis, Nicholson and R. Etheridge, jun., Journ. Linn. Soc., 

 vol. xiii. p. 361, PL XX., figs. 15-17. 



Spec. Char. Corallum composed of broad flattened branches 

 having a width of from four to seven lines or more, with a 

 thickness of from two to three lines, often coalescing to form 

 flat reticulate or palmate expansions (PL IV., fig. 2). Corallites 

 essentially polygonal in shape, tolerably equal in size, from one- 

 third of a line to two-fifths of a line or rather more in diameter. 

 Walls of the corallites greatly thickened by a secondary 

 deposit of sclerenchyma, which is laid down in delicate con- 

 centric laminae in the interior of the tubes, and increases 

 considerably in amount as the mouth is approached (PI. IV., 

 figs. 2 a and 20}. Calices covering the entire free surface of 



