PALAEOZOIC CORALS AND FORAMINIFERA. 



95 



often transversely septate in the middle and having solid polygonal 

 divisional walls to the stars — characters completely at variance 

 with those of the recent and mesozoic Astrcece, and indicating 

 important differences in the animals and mode of increase. 



Abundant in some parts of the carboniferous limestone near 

 Bakewell, Derbyshire ; more rare in the same formation at 

 Cor wen. 



{Col. University of Cambridge.) 



Heterophyllia (M^Coy), n. g. 

 Gen. Char. Stem elongate, subcylindrical, irregularly fluted lon- 

 gitudinally : horizontal section, few, 

 distant lamellae destitute of any order 

 of arrangement, but irregularly 

 branching and coalescing in their 

 passage from the thin solid external 

 walls towards some indefinite point 

 near the centre, where the few main 

 lamellae irregularly anastomose : ver- 

 tical section showing about the middle 

 an irregularly flexuous line (the edge 

 of one or two of the radiating vertical 

 lamellae), from which on each side a 



row of thin, distant, sie-moidally rj , , „. . • ,• 



, ^ , , 1 IT 1 "^ Heterophyllia: a. exteriOY oi 



curved plates extends obhquely up- stem ; 6. horizontal and 

 wards and outwards, forming a row of vertical section. 

 large rhomboidal cells on each side. 



The paradoxical characters of the lamellae — their perfect want 

 of symmetry of disposition, and their irregular branch-like union 

 among themselves, together with the remarkable openness of the 

 cellular structure, render those corals totally unlike any other 

 recent or fossil group. From Cladocora and Caryophyllia, to 

 which they are most allied, they are distinguished by the want 

 of the cellular axis, and by their few, unsymmetrical and anasto- 

 mosing lamellae. I suspect the Cladocora ? sulcata of Lonsdale 

 may belong to this group, but I have not seen examples of it 

 myself. 



Heterophyllia grandis (M'Coy) . 



Sp. Char. Stem slightly flexuous, about 5 lines in diameter, 

 scarcely tapering in 3 inches, longitudinally marked with deep 

 unequal grooves, and few, large, polygonal, unequal ridges, 

 giving a very irregularly angulose section to the stem ; surface 

 smooth ; internal structure as given in the generic character. 

 Rare in the carboniferous limestone of Derbyshire. 

 {Col. University of Cambridge.) 



