Appendix to Part I. 183 



3. Fe^estella fossela, sp. n. 



Cup-shaped, celluliferous surface internal; branches dichotomous, 

 slender ; meshes oval ; roivs of cells, two ; transverse processes 

 non-cellular ,• inner layer of non-celluliferous surface minutely 

 fibrous ; external layer smooth or granular. 



In general aspect and structural details, this species bears a great 

 resemblance to Fenestella flustracea of the niagnesian limestone of 

 England (Retepora flustracea, ' Geol. Trans.,' 2nd series, vol. iiL 

 pi. xii. f. 8), .but it differs from it in the peculiar character ex- 

 hibited in the cast of the celluliferous surface, the nature of which 

 will be given in noticing that surface. 



The principal specimen is a nearly perfect cup 1^ inch in height, 

 and about two inches across the widest, compressed part. There 

 are no marked variations of character, but occasionally, Irregu- 

 larities of growth, due, apparently, to accidents during progressive 

 development. 



The following details have been obtained from casts, no perfect 

 surface having been noticed. — The branches had great uniformity of 

 dimensions, swelling but very slightly at the distant points of bifur- 

 cation, and their thickness was apparently nearly equal to their 

 breadth. The cast of the cellular surface is traversed along the 

 centre by a sharp narrow trench (fossula), with nearly vertical 

 sides, the distinguishing character between this species and Fen. 

 flustracea. The cylindrical casts of the mouths, or the interior of 

 the cells, are arranged in a single row on each side of the trench, 

 and no increase of number is clearly perceptible at the bifurcations. 

 Along the centre of the trench is a row of indentations or minute 

 conical pits, a character noticeable in other species, particularly in 

 Fen. flustracea. They are plainly not casts of cellular openings, 

 but of relatively large papillae. Traces of such projections have 

 also been noticed in several other instances. 



The mouths of the cells, in the minute fragment which has been 

 obtained exhibiting them, are large, round, slightly projecting, and 

 not very distant, and in the same atom is an imperfect keel. The 

 remains of the non-cellular surface exhibit no characters requiring 

 notice, but indications of a striated and smooth layer have been 

 observed. 



The two specimens which afforded these structural details have 

 a matrix of dark-coloured, hard limestone. 



Hemitrypa sexafgeea, sp. n. 



Net-iuorli fine, hexagonal^; meshes round in double roius. 



The coral to which the above inefficient characters are applied, 

 is imbedded in the shaly surface of a dark, hard limestone. It is 



