154 DR G. W. LEE ON 



Minor septa fairly well developed, but irregular and not reaching to the tabular area. 

 The cardinal fossula is indistinct, and can only be recognised in some sections by a 

 shortening of the cardinal septum, towards which the axial columella is directed. 



Vertical Sections. — The median vertical section figured (PI. I. fig. 2) sufficiently 

 indicates the nature of the tabulae and dissepiments. The latter are developed at an 

 early growth-stage. 



lie mi irks. — Certain sections (e.g. PL I. fig. 2a) of this species closely resemble 

 that figured by Thomson * as Acrophyllum sp., but in the latter the major septa are 

 allccted by a thickening of stereoplasma within the tabular area. 



In distal transverse sections (PI. I. fig. 1) the central area of Lophophyllum cher- 

 neyense approaches in structural character that of a Dibunophyllum. As regards the 

 septa and columella, the Lophophyllwm stage is strongly marked in the younger stages 

 of the new species (PL I. figs. 2a, 2d), while the tabulae throughout approximate to a 

 Lophophyllum type, as opposed to Dibunophyllum, where the tabulae have a distinct 

 central area in which they are more numerous and vesicular. 



Probably all the Dibunophylla pass through a Lophophyllum stage, but assume 

 their characteristic features at so early a period that as a rule they are readily separable 

 from the later genus. 



Lophophyllum sp. (PL I. figs. 7, 7a.) 



Of this species, apparently new, there is only a single example in the collection, and 

 the conical end is missing. The corallum is continuously conical and slightly curved. 

 The calyx is deep (4 cm.), the diameter of the rim being 4 - 5 cm. The ejpitheca is thin, 

 smooth, with a few lines and constrictions of growth. The columella is a prominent 

 feature but from the vertical section (PL I. fig. 7a) is apparently discontinuous. 

 As the specimen is embedded in limestone, it is not possible to say whether this is in 

 reality the case, or is only due to a slight twist in the corallum taking the columella out 

 of the plane of section at this point. 



The cardinal fossula is clearly visible in cross section (PL I. fig. 7), owing to the 

 sharply marked boundary of the tabular area encroaching on the dissepimental zone at 

 this point. 



Incert^ Sedis. 

 Genus Hexaphyllia Stuckenberg. 



Heterophjllia, M'Coy (pars). 



The genus Hexaphyllia was established by Stuckenberg t for those species of 

 Heterophyllia with six septa only. Although the multi-septate forms of M'Coy's genus 

 (e.g. Heterophyllia grandis) probably pass through a hexameral stage early in life, still 



* " Corals Carb. Syst. Scotland," pi. xi. figs. 14 and 14a, Proc. Phil. Soc. Glasgow, 1883. 



+ " Anthoz. u. Bryoz. d. miter. Kolilenkalks v. Central Russlande," Mem. Com,. Geol. Russie, nouv. ser., livr. xiv. 

 (11MJ4), p. 72 of German text. 



