LONSDALE ON EOCENE CORALS FROM N. AMERICA. 513 



scribing Madrepora trochiformis, or the M. simplex turbinata of 

 Fougt, a well-known Gothland coral of similar characters, says that 

 it perhaps lived in sand.* These remarks are submitted to the 

 reader's attention, because some free or sharply terminated corals 

 exhibit signs of not having been permanently invested by the 

 polype. 



Only casts of the terminal cup and of portions of the exterior 

 of F. ? cuneiforme were examined.f The chord of the arched or 

 upper extremity of the interior of the cup was in some cases nearly 

 an inch, and the inferior parallel breadth and the greatest depth 

 were both five lines. These dimensions, it is conceived, would 

 leave for the lower part of the cone, or that in which the lamellae 

 were centrally united, a depth of five lines. The lamellae as well 

 as the other portions of the original coral were wholly removed ; 

 but from the curved impressions on the casts of the interspaces in 

 the terminal cup there had evidently been no union of the lamellae 

 along the central line, but an open narrow space, while the base 

 of the casts uniformly exhibited as clear proofs of a perfect 

 blending or reticulated structure. The lamellae which lined the 

 cup were shown by the same means to have been of unequal 

 breadth, and to have had finely tuberculated surfaces. The thin- 

 ness of the original wall was proved by the narrow interval 

 between the casts of the cup and of the exterior, and its forami- 

 nated structure by numerous filiform processes which traversed 

 about half the interval. 



M. P. Gervais identifies Flabellum pavoninum (Lesson), with 

 Turbinolia rubra (Guoy et Guimard) ±, but he.affords no additional 

 information respecting the earlier habits of the polype. Whether 

 the American fossil was at any time wholly enclosed in the animal, 

 the specimens afforded no means for determining ; but there can 

 be no doubt that it, as well as others believed to be generically 

 identical with it, was not only attached by the base, but received 

 additional support, during one period of growth at least, from 

 lateral appendages developed sometimes slightly, sometimes to a 

 considerable extent. These processes, which often exhibit sharp, 

 fractured edges, were evidently formed by secretions trans- 

 mitted through the minute channels visible in them, and connected 

 with the interior structure; while their variable dimensions, as well 

 as unequal distribution in different species, depended apparently 

 upon the form and wants of the animal, or the degree of irritation 

 arising from its having occupied a sheltered or exposed position. 

 Their existence, it is believed, necessarily leads to the conclusion 

 that the exterior was not, during a certain portion of the polype's 

 life, covered by a soft persistent mantle conforming in shape to 

 the outline of the coral ; nor does it appear that any of the fossil 



* Elenchus, German translation, pi. 2. p. 59. 1787. Consult also Dr. Fleming's 

 notice of Fungia turbinata. Wern. Mem. vol. ii. p. 250. 



+ Tt has been found necessary to omit figures of these which had been prepared. 



\ " C'est le meme animal que le Turbinolia rubra." Sup. Dec. Sc. Nat. t. i. 

 p. 484. 



ji M 3 



