72 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Of the earliest state of the cells no positive information has been 

 obtained* ; but it is inferred from the ribs, more or less distinctly- 

 traceable on the outer covering, that they were in the young stage 

 entirely open, and that the outer surface was produced by a uni- 

 form development of rib-like processes from the side-walls of the 

 cells, in the same manner as in certain species of recent Escharina. 



In the only observed case of a perfect outer layer (c), the cells 

 were oblong and slightly hexagonal, and separated by a faint, 

 depressed line. The external surface was, to a small extent, convex ; 

 and ribs, though they were not prominent, could be detected, con- 

 verging from the proximal and lateral walls towards the centre ; 

 and the medial line of junction might also be discovered. The 

 perfect mouth, placed in the middle of the distal extremity, was 

 small and round, and in the same plane with the outer surface, but the 

 lips projected slightly. The hemispherical gemmuliferous vesicles 

 were relatively large, and comparatively numerous. They were si- 

 tuated immediately over the mouth, and they altered the position of 

 that orifice from a horizontal to an inclined position. The accessory 

 foraminated vesicles were variable in outline but constant in occur- 

 rence and situation, springing from the sides of the mouth, and 

 increasing in size as they ranged upwards and outwards. The 

 foramen was often well denned. From the position of these ve- 

 sicles, the breadth of the distal extremity was apparently much 

 increased. 



In subjacent or older layers (b) the substance of the coral was not 

 often preserved, having been detached with the overlying series, 

 and leaving only calcareous casts of the interior of the cells ; but 

 where it is retained, there were no marked differences of cha- 

 racters, as far as observation extended, except in the absence of 

 gemmuliferous vesicles. The mouths did not appear to have been 

 filled up by the animal, and the foramina of the accessory vesicles 

 were occasionally open : the depressed lines between the cells were 

 also preserved. 



In fragments which exhibited only casts of the cells, the indi- 

 cations of the ribs were sometimes as strong as on the outer 

 surface, and the form of the mouth was well shown ; but there 

 were only very slight indications of the accessory vesicles. 



Of the lateral connecting foramina nothing decided was ob- 

 served in consequence of the perishable state of the layers ; but if 

 the imperfect cells mentioned in the note * belonged to Escha- 

 rina (?) sagena, the foramina were numerous. 



The dorsal surface along the medial plane of separation (a) 

 very much resembled that of Flustra foliacea, when artificially 

 exposed. 



Locality. — Timber Creek. 



* On the surface of one specimen, some immature cells, consisting of only the 

 dorsal and side walls, were observed, occupying the exact position of an ordinary 

 layer of Escharina sagena, but there were no proofs that they belonged to that 

 species ; and all attempts to connect their structural details with those of the 

 coral under consideration failed. 



