OF SOUTHERN INDIA. 
]I 
colonies generally broadly foliaceous and branclied, tbe cells arranged in two oppo- 
site layers on tbe compressed branches, separated by a lamina. 
A typical species of this genus is E. d’ Orb., and the greater number 
of those described by the same author under Eschara also belong to it. 
11. Vincularia, Dcfr., 1829. 
Cells quite similar to those of Escharinella, but arranged in a single layer all 
round the siu’face of cylindrical, branched stems, without an intervening lamina. 
This genus is very extensively represented both in fossil and in recent state ; 
it only differs from Salicornaria by the branches of the colonies being continuous 
and permanently attached to each other without any articulation. 
Next to Vincularia comes Ilagenow’s Inversaria,* merely differing from the 
former by the hollow axis of the stems. Whether this excavated axis is really 
natural and peculiar to that genus, or whether it is simply the result of some soft 
organic substance having been lost by decay, has, I think, yet to be proved by fur- 
ther observations. 
12. Bijlustra, d’Orb., 1852. 
Cells depressed, surrounded by a raised margin and widely open in front, as in 
3Iembranipora ; colonies foliaceous and branched, with the cells arranged in two 
opposite layers, separated by a lamina. B. regidaris, d’Orb., from the Chalk may 
be regai’dcd as the typical species of this genus, which is largely represented 
in a fossil state, but is more rarely found recent. 
Of the uniserial species, Filijlustra, Byripora, and FiUJlustrellaria of d’Or- 
bigny ought, I believe, to be referred to the membranipokinm. On the other hand, 
the free growing species represented by Cupularia, Trocliopora, &c., have to form 
a separate family. The same applies, I believe, to Myriozoum and Melicerites, which 
no doubt belong to the close proximity of Nodelea, Escharites of Rdmer, and their 
allies, &c., and which have by d’Orbigny been separated into two distinct families, 
though one common name w'ould probably suffice for both, 
I should also mention Retepora, w'hich is often classed next to Eschara. But 
the structm*e of the colony of He.lepora aiipears to be a very peculiar one ; the sub- 
stance contains a considerable proportion of silica, and I am inclined to uphold the 
old family BbtbporidjE as distinct from the Celleporib^. Next to Retepora will 
no doubt have to be classified Filiflustrella, and probably also Filijlusirina of 
d’Orbigny, while Gabb and Horn’s Bhidolopora (Journ. Acad. Nat. Sc., Phil., 
2nd ser., vol. v, p. 138,) does not in the least differ from Retepora, as generally 
understood. In the species Rli. labiata, described by the American authors, some 
of the cells merely have below the aperture a special or avicularian pore, margined 
below by a raised horse-shoe-shaped margin, gradually sloping towards the base of 
the cell, but a similar structure is to be found in nearly all the Reteporm which I 
have had occasion to examine, both recent and fossil. 
* Bryozoen Maast. Kreide, 1851, p. 57. 
( 45 ) 
