16 J)r. H. A. Nicholson on some new or 



millims. in its greatest length, which is subdivided by a series 

 of well-developed septa. The septa are alternately long and 

 short, about thirty-six of each series existing in a corallite of 

 25 millims. width, flexuous, the longer ones extending to near 

 the centre of the visceral chamber. Traces of vertical lamellee 

 also exist in the exterior vesicular zone, these representing 

 the imperfect outward prolongation of the septa from the inner 

 area. Dissepiments (which are really only the cut edges of 

 the ascending tabulaj) are developed in the outer portion of 

 the central tabulate area. The tabulae are well developed in 

 the central portion of the corallites, where bounded by the inner 

 mural circle, being close-set and nearly horizontal in the 

 middle of this region, but becoming sharply bent up towards 

 its margins. 



Obs, I have founded this species upon a single well-pre- 

 served specimen in the possession of M. (Ehlert. 



The specimen in question exhibits four corallites, of which 

 two are quite separate from the others, standing at a distance 

 respectively of 2 and 11 millims. apart from them, while the 

 remaining two are in contact for a distance of nearly 2 centims., 

 the one being indented by the pressure of its neighbour. 

 Even in this case, however, the contiguity is not attended by 

 any real union or amalgamation, the two corallites being each 

 provided with its own distinct epitheca, and being quite 

 readily separable from one another. The basal portions of 

 the corallites are enveloped in the matrix ; and their precise 

 mode of origin is therefore uncertain. 



As regards the internal structure, the points most worthy of 

 notice will be readily recognized by reference to the preceding 

 description and by the accompanying drawings of the trans- 

 verse and vertical sections of one of the corallites (figs. A and 



There can be no doubt that the present species is a true 

 EndopIiT/Uum, in spite of the fact that the corallites possess a 

 distinct epithecal investment, and that this structure is stated 

 by Milne-Edwards and Haime to be wanting in this genus. 

 In all the points of its internal structure, however, it entirely 

 agrees with the other recorded species of the genus ; and the 

 development of the epitheca must therefore be taken to be a 

 variable character. In point of fact E. abditum, E. & H., 

 does possess well-developed walls to the corallites, and the 

 absence of an epitheca is probably only due to the coalescent 

 condition of the corallites. 



From E. abdittim, E. & H., the present species is at once 

 distinguished by the disjunct condition of the corallites and 

 their much smaller size. 



