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 authorit}^ On the other hand, Dr Lindstrom 

 (Ann. Nat. Hist., sen 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 /ct//^ 

 (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. 



