﻿568 MR. A. WILMORE ON THE CARBONIFEROUS [Nov. 1 9 10, 



in length, and the width reaches about 2 inches. Constrictions 

 of growth are frequent, and thus the corallum expands and con- 

 tracts continually. 



A transverse section shows four areas : — 



(1) Central area showing tabulas only, which varies in width with the plane 

 of the section. - ■ ...... 



(2.) A medial area occupied by the major septa. These are often greatly 

 thickened towards the inner wall, but taper to a thin plate as they 

 end off on the tabulae. There are about sixty major septa in the 

 large specimens. The septa are thickened very unequally, some 

 specimens having nearly all the major septa thickened, but others 

 showing clusters of such thickened septa. These clusters are not 

 always near the distinctly marked fossula. The septa vary con- 

 siderably in length, according as the section has been near the 

 upper surface of a tabula or at some distance from it. 



(3) A narrow zone of dissepiments, through which the prolongations of 



the major septa pass. There is thus an inner wall, and the short and 

 irregular minor septa project from this wall for a short distance into 

 the medial area. 



(4) A narrow peripheral zone of larger, laterally elongated vesicles, 



without any septal prolongations. 



A longitudinal section shows that the tabulae are exceedingly 

 irregular, both in distance apart and in manner of growth. Two 

 or three often unite as they approach the inner wall (the inner 

 edge of the dissepimental zone) and these dip sharply together. 

 Usually there is a wide gap above such a grouping of tabulae. 



The irregular tabulae and the narrower zone of dissepiments, 

 as well as the irregular growth of the corallum, distinguish this 

 coral from the true Caninia gigantea, Mich. Hence I propose to 

 constitute it a new species, provisionally, and to name it Caninia 

 Jiettonensis, from the village of Hetton, near the Yorkshire Dales 

 Railway. 



I have found this coral at Owslin Barn, near Hetton ; at Winter- 

 burn ; at Farlands, near Airton ; at Crag Laithe ; and in Swinden 

 Knoll. It is not so common as the normal O. gigantea. 



Caninia cf. stjbibicina, M'Coy. (PI. XXXIX, figs. 1-3.) 



This is fairly common in the knolls, and I have found it in the 

 well-bedded limestones of the knoll region. It is especially common 

 at Swinden Quarry. A variety (recognized for me by Mr. It. G. 

 Carruthers) has closer septa and closer tabulae, with the dissepi- 

 mental zone fairly normal ; another variety has normally spaced 

 septa, but with an outer area of decidedly irregular character. The 

 dissepiments are much larger, and are often in the form of large 

 vesicles. In this respect it approaches Caninia gigantea. This 

 variety I have only found at Elbolton. 



