332 TABULATE CORALS. 



with complete, horizontal, closely-set tabulae, and presenting 

 quite rudimentary septa ; " while they regard the surface-tuber- 

 cles as processes springing from the edge of the walls (Brit. 

 Foss. Cor., p. 269). Professor Martin Duncan (Third Rep. on 

 Brit. Foss. Corals; Rep. Brit. Ass., 1871, p. 128) appears to 

 take nearly the same view of the affinities of Labechia as that 

 put forward by Edwards and Haime ; but he considers that it 

 should be regarded as simply a sub-genus of Monticulipora. 

 No evidence, however, in support of this view is actually ad- 

 duced, so that I can merely mention the opinion held by this 

 distinguished authority. On the other hand, Dr Lindstrom 

 (Ann. Nat. Hist, ser. 4, vol. xviii. p. 4) correctly pointed out 

 that there is not in Labechia " the least trace of any wall cir- 

 cumscribing any calicle, or of any septa ; " and he adopts the 

 view which will be more fully noticed at a later period that 

 the genus is not Actinozoan at all, but truly Hydrozoan in its 

 affinities. Lastly, the internal structure of Labechia, as eluci- 

 dated by means of microscopic sections, was, so far as I am 

 aware, first pointed out by Dr Murie and myself in a memoir 

 upon the Stromatoporoids (Journ. Linn. Soc., vol. xiv. p. 232). 

 The skeleton of Labechia is calcareous, and entirely resem- 

 bles that of many of the composite Corals in its general form 

 (fig. 44, A), constituting, as it does, a laminar expansion, attached 

 by a basal peduncle, and having its lower surface covered by 

 a concentrically -striated epitheca. On looking at the upper 

 surface of the colony (fig. 44, B, and PI. XV., fig. 4 a), the 

 most striking feature is the apparent total absence, even in the 

 best-preserved examples, of any of the apertures or " calices " 

 that one would expect to find in any normal compound corallum. 

 On the contrary, the whole of the upper surface is covered 

 by a thin imperforate calcareous membrane, which is studded 

 closely and throughout with blunt, elevated, conical, or elon- 

 gated solid tubercles, which sometimes run into one another 

 and give rise to vermicular ridges. No other features than the 

 above can be recognised by a mere examination of the exterior 

 of the perfect corallum. As regards the internal structure, 



