3 o8 TABULATE CORALS. 



is especially shown by the fact that the tabulae of the angular 

 corallites in both species give rise to a series of convex lentic- 

 ular vesicles (compare fig. 39, B, and PI. XV., fig. 3 b). The 

 large round corallites of F. incrassata are, however, nearly 

 twice as large as those of F. minor, and are only separated by 

 a single row of angular tubes, while they are provided with 

 more numerous tabulse, these features alone being sufficient to 

 establish the specific distinctness of the two forms. 



Formation and Locality. In the Lower Carboniferous Lime- 

 stone of Cousland, near Edinburgh. Collected by Dr R. H. 

 Traquair. 



Fistulipora incrassata, Nich. 

 (PI. XV., figs. 3-3*) 



Callopora incrassata, Nicholson, Geol. Mag., Dec. ii. vol. i. p. 13, PI. II., fig. i, 

 1874; Rep. Pal. of Ontario, p. 61, fig. 19, 1875. 



Spec. Char. Corallum sometimes forming thin crusts, at- 

 tached parasitically to foreign bodies, or partially epithecate 

 below, or at other times constituting irregular masses of con- 

 siderable size. Large corallites, oval or pyriform in section, 

 one end being wider than the other, and the junction between 

 the two commonly being marked by two small laminar inflec- 

 tions of the wall of the tube on opposite sides. The large 

 tubes are about a third of a line in their long diameter, and 

 their calices project slightly above the general surface, while 

 they are completely separated from one another by the inter- 

 mediate " small " corallites. These latter are angular in form, 

 and there is never more than a single row of them between any 

 given pair of the large corallites. Their mouths are seldom dis- 

 tinctly shown, and are often closed by a thin calcareous mem- 

 brane. At intervals the surface shows star-shaped depressed 

 "maculae," which are entirely occupied by the angular coral- 

 lites, and which are often covered by a superficial calcareous 

 pellicle. Owing to the variable shape of the angular corallites, 



