1848.] LONSDALE ON FOSSIL ZOOPHYTES. 85 



brought in close contact with the subjacent surface, and inverted 

 portions on being re-exposed are overlaid. On the contrary, through- 

 out the fine series submitted to examination, not the least attempt was 

 detected, under any irregularity of growth, to assume a turbinated 

 outline, with a large pedicle, surrounded by a solid lamina — a mode 

 of growth characteristic of Ehrenberg's Manicina, a dismemberment 

 from Meandrina; also of some fossil Anthozoa; and due, in the former 

 case at least, to the edge of the mantle being free and inclined up- 

 wardsf . 



Of the earliest plan of development, or from a single germ, no in- 

 stance was observed ; nor of a state resembling that which in some re- 

 cent and extinct genera distinguishes the period when the coral natu- 

 rally ceased to increase in part or wholly J. The specimens gene- 

 rally varied in diameter from about 1 to rather more than 3 inches ; 

 the largest was an amorphous mass nearly 4 inches high, 3^ wide, 

 and 2^ thick. 



The original substance of the coral was rarely preserved on the 

 exterior ; but in two beautiful examples belonging to the Geological 

 Society's Museum, one of which was obtained by Dr. Fitton at the 

 Red Hill cutting near Reigate (fig. 14), it prevailed over the whole sur- 

 face, and presented a uniformly opake- white layer. In polished sec- 

 tions of the interior it constantly occurred under the form of opake, 

 w^hitish lamiuEs ; generally, however, the specimens displayed externally 

 broad, rounded casts (fig. 12*), in brown calcareous spar, of the 

 inner surface of the original layer, in those cases in which the deve- 

 lopment of a set of structures had been completed previously to de- 

 struction ; but in those in which that event happened while the work 

 was in progress, the surface gave casts of narrow ridges with interme- 

 diate hollows or furrows (fig. 15). 



The area of mature abdominal cavities rarely exceeded a line in 

 djameter, and was often less, measuring from the lateral union of the 

 lamellae ; while that of the simple stomach-sac, marked by the in- 

 terval between the edges of the four projecting plates, was about half 

 a line. The greatest depth of the cavity, so far as could be ascer- 

 tained, was also one line. The shape was irregular, but a rounded 

 outline prevailed, the periphery being defined by the sidewise-united 

 lamellae, without a trace of a distinct lining. The laminae forming 

 the base of the cavity were apparently concave or uneven, judging 

 from the casts ; and a similar character was shown in vertical sec- 

 tions. Beneath the last-occupied abdominal space, prominently de- 

 fined in purposely-exposed interiors by a series of notches (fig. 13), 

 occur numerous curved laminae, forming a complicated cellular struc- 

 ture, which is sometimes tTaversed perpendicularly by the edge of a 

 projecting lamella. The whole downward range of these deserted 



t Ehrenberg, Beitrage, p. 101. For clear delineations of the mode of growth 

 among recent species, consult Sol. and Ellis, or Lamouroux, tab. 47. fig. 4 and 5, 

 tab. 51. fig. 1 ; also Esper, Pflanzenthiere, Madrepora, tab. 4 : and among fossil 

 corals, see M. Michelin, Iconog. Zoophytol. pi. 44. fig. 9a, pi. 51. fig. 1 and 4, 

 pi. 54. fig. 9, pi. 68. fig. 4, and pi. 70. fig. 1 a and ia. 



X Quart. Joiirn. of the Geological Society of London, vol. i. p. 498-499, 1845. 



