LONSDALE ON EOCENE CORALS FROM N. AMERICA. 515 



ing of a vertical layer traversed by the outer extension of the 

 lamellae, and it is not visibly foraminated ; but in the Alabama 

 fossil the boundary is highly perforated, as well as the portions of 

 the lamellae immediately adjacent, the whole composing a reticu- 

 lated almost spongeous structure. This aggregate of differences 

 marked, it was conceived, something more than a specific distinc- 

 tion from the typical Turbinoliae with which the comparison was 

 made. 



In extending the inquiry to other fossils for the purpose of 

 ascertaining if similar essential structures could be detected under 

 modified conditions, it was found that they were all combined in 

 that manner in Turbinolia elliptica, with the addition, however, 

 of clear proofs in different specimens, that this coral was at one 

 time fixed, but at another free. How far the habits of species 

 may render necessary a prolonged or brief attachment, or even 

 one of so short duration that a very minute individual would be 

 necessary to afford signs of a once fixed base, no information has 

 been obtained ; but it is conceived that the want of such a charac- 

 ter in the Alabama coral cannot be regarded as more than a minor 

 specific distinction. 



No lateral processes adapted to afford additional support were 

 noticed in either of the fossils, nor any impediments to the exterior 

 having been perfectly enclosed by the polype, the plan of pro- 

 ducing the uniform thickening not being incompatible with such an 

 envelopment ; nevertheless, no indications of it were observed 

 beyond the absence of parasites and of interruptions to the uniform 

 production of the papillae. 



In the characters of the lamellae, the manner of their blending 

 with the outer wall, and the general nature of the exterior, these 

 polypidoms agreed with the Dendrophyllice of M. De Blainville ; 

 while the mode of growth was perfectly dissimilar. This union 

 in the same coral of the habits of Ehrenberg's Fungina with the 

 structures of some of his Ocellina, families belonging to distinct 

 orders in that author's classification, is considered of sufficient 

 importance to deserve the reader's attention being directed to it. 



Believing that the Alabama coral (fig. a), the species called 

 Turbinolia elliptica, and probably T. semigranosa, have a unity 

 of composition and more than specific distinctions from T. crispa, 

 T. sulcata, and T. mixta, it is proposed to consider them as the 

 basis of a new genus, for which the term Endopachys * was sug- 

 gested by Mr. Lyell, and the following characters are proposed : — 



A stony Iamelliferous coral, single, conical or wedge-shaped, fixed in the ear- 

 lier stages of growth, free in the older; lamella? numerous, variahle in character, 

 grouped, highly foraminated near the centre and periphery ; no transverse dia- 

 phragms ; middle a union of broader lamella?, with a transverse reticulation ; 

 boundary wall greatly foraminated, so blended with the lamellae as to form at 

 the junction a reticulated structure, progressively thickened by papilla? secreted 

 from within ; detached base gradually overlaid by papilla? similar to those of the 

 general surface, 



* Evdov, within ; iraxus, thick : in allusion to the thickening from within. 



M M 4 



