720 R. F. TOMES ON THE OOLITIC 
of Champlitte under the name of Trochoseris corallina, which has 
as many as 120 unequal septa, or nearly double the number of those 
of the present species. 
Genus THamnastr#a, Lesauvage. 
Of the generic claims of the Coral-Rag Thamnastree, I can only 
speak definitely in so far as some of the species are concerned. The 
first on the list has true synapticule and imperforate septa, and most 
likely the same characters appear in the second. These are probably 
true Fungide ; but the other species have not yet received that close 
attention which is essential for their proper determination. I 
prefer therefore, for the present, to leave the genus where I find it, 
rather than to make divisions which would perhaps render necessary 
a complete revision of the nomenclature of the group. 
THAMNASTRHA ? LATIMMANDROIDEA, n. sp. Pl. XXXII. figs. 18, 19. 
In the external conformation of the corallum this species so closely 
resembles some species of Latimeandra, that I placed it in that 
genus until the discovery of synapticule rendered its presence among 
the Astrzeidz impossible. 
The general outline of the upper or calicular surface may be 
described as moderately convex, and as having an irregularly ovoid 
but lobular outline, the corallites being on some parts of the corallum 
divided into groups of 8 or 10, which are completely surrounded 
by an outer or common wall, somewhat as in the Chorisastrea dubia 
of Becker * and the C. corallina of M. de Fromentel 7. 
So far as may be observed from the condition of the specimen, 
there has been a thin epitheca, which, being for the most part lost, 
reveals mural coste, which, though not strongly marked, are very 
uniform in size and persistent, and bear some resemblance to those 
of Thamnastrea arachnoides. 
The calices are mostly simple, being in series in two parts of the 
corallum only. In one of these there are two calices, and in the 
other five. The walls enclosing the calices are well developed and 
prominent, and the latter are deep, and have a well-marked and 
spongy columella, which is rather large in size. The septa are thin 
and anastomose a good deal. There are about 60 in a simple calice ; 
about 12 of these, constituting the first cycle, pass into the columella, 
and all the others, according to their rank, unite at different points 
with the primary ones, and occasionally with the secondary ones, 
and form groups, somewhat as in the Z'rochoseris Morris: described 
by Prof. Duncan from the Cretaceous formation of Haldon {. 
The synapticule are not very regular in their development, but 
are in distinct lines, which correspond to the margins of the septa. 
They are true synapticule, and very nearly resemble those of 
Thamnastreea arachnoides. I fail to detect pores in the septa; and 
if the latter are imperforate the species would fall within the defini- 
tion proposed for the family Fungide by Milaschewitsch, that is to 
* Paleontographica, vol. xxi. + Polyp. Corall. de Gray, pl. vii. fig. 5. 
} Quart. Journ. Geol. Soc. vol. xxxv. p. 94, pl. viii. fig. 14. 
