380 PROF. 8. H. REYNOLDS AND DR. A. VAUGHAN ON [Allg. IO^I, 



normally no tabulse. Such a phenomenon may perhaps find a 

 parallel in the unwinding of the most highly-developed ammonites. 

 The specimen is from the upper part of S . 



Diphyphyllum. 



DlPHYPHYLLTTM 8p. (PI. XXXI, fig. 7.) 



It is difficult to decide to which of the following genera to refer 

 this fine coral : — 



Campophyllum Ed. & H., emend. Oarruthers. 

 Koninckophyllum Nich. & Thorns. 

 Lophophyllum Ed. & H., emend. Carruthers. 

 Diphyphyllum M'Coy, emend. Vanghan. 



Campopliyllum is never columellate. 

 N Koninckophyllum is best confined to strongly columellate forms, 

 with a thick external area made up of closely-packed 

 vesicles, and with minor septa projecting (as in LitJio- 

 strotion) beyond the vesicular ring. 

 Lophopliyllum, as figured by Mr. Carruthers, 1 differs very markedly 

 from our species in the insignificance of the minor septa 

 and in the highly- developed central structure in the adult. 

 Our form is practically non-columellate, although consecutive 

 tabulse are occasionally ridged in the centre, when a crest is formed 

 which reaches from tabula to tabula. This phenomenon is highly 

 characteristic of Diphypliyllum, to which genus I have referred the 

 species. 



It is not unlikely that our form is a direct descendant of 

 Diphypliyllum subibicinum (M'Coy), a species which has its 

 maximum in C-S and ranges through S ; variation must be 

 assumed to have resulted in increased thickness and packing of 

 the external ring, and in the occasional ridging of the tabulae. 



The Burrington form occurs at D x , and is convergent with 

 Koninckophyllum 6. 



Clisiophyllid. 



An early Clisiophyllid. (PI. XXXI, fig. 3.) 



The central area is composed of a thick plate, surrounded by 

 three or four strong concentric intersections which are crossed 

 by short, thin, discontinuous lamellae. 



The major septa are thick and moderately spaced. The minor 

 septa are equally thick, short but prominent. All the septa are 

 attached to the wall' by their thickened ends, and practically no 

 vesicles are developed. 



Judging from similar forms in C and C-S, the columella with its 

 thin coating of vesicles projected as a tall, laterally compressed 



. l ' A Carboniferous Fauna from Nowaja Semlja with Notes on tbe 



Corals by B. G. Carruthers' Trans. Roy. Soc. Edinb. vol. xlvii (1909) pp. 152 

 ei segg. pi. i, figs. 1-2 d. 



