3o8 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. mcrassata 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 tabulae, these features alone being sufficient to 

 establish the specific distinctness of the two forms. 



Formaiion 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 

 "macula;," 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. 



