690 A. W. WATERS ON FOSSIL CYCLOSTOMATOUS 
at the side, and there may be three or four to each zocecium; on the 
dorsal surface of the zoarium there are smaller openings than these 
lateral ones just mentioned. On the front the lamina is very marked, 
and rises above the zocecia on each side, and there is a tendency for 
this to divide up the centre of the lamina, and I find the same ten- 
dency in the Reticulipore from the Chalk of Royan. In Biflustra 
the two layers of cells being readily separable was made a generic 
characteristic, but perhaps it depends to a large extent upon the 
condition of fossilization. 
The closure occurs at some little distance before the zocecial tube 
becomes free (see Journ. Linn. Soc. vol. xvii. pl. 17. fig. 5), viz. about 
0-13 millim. from the termination of the zocecia, and in one or two 
cases there is a second closure a very short distance behind the first. 
This species is closely allied to Reticulipora obliqua, d’Orb. Pal. 
Frang. p. 906, pl. 610. figs. 1, 6, pl. 768. figs. 1-2, from the Senonian, 
but I do not think they can be considered the same species. 
18. DiscorusteERA cLypEaTA, Lamx. Pl. XXXII. figs. 15, 16, 19. 
Pelagia clypeata, Michelin, Icon. Zooph. p. 229, pl. lv. fig. 3. 
Apseudesia elypeata, Haime, Bry. Form. Jur. p. 202, pl. vii. fig. 7. 
This genus was first described as Pelagia by Lamouroux; but as 
the name had already been used for an Acaleph, it had to give way, 
and was partly replaced by Defrancia; but this seems to have been 
used for such various things that it is not always clear what has 
been meant, nor can we feel satisfied whether both Defrancia and 
Discotubigera should be retained. 
The zocecia are raised up in rays in the same way as in Licheno- 
pora; but there are no interstitial pores, and therefore I believe the 
genera are widely separated. 
We must extend d’Orbigny’s definition of Discotubigera to species 
growing more or less free. 
The specimen from Aldinga is 20 millim. in diameter, with about 
40 principal bi-triserial rays, with zocecial openings about 0-12 millim. 
The rays near the centre are very narrow, and one or a pair of cells . 
oiten terminate at a short distance from the centre, and others also 
terminate before the fasciculine openings. Near the circumference 
there are short rays inserted between the main ones. Near the 
border there is a slight ovicellular inflation, and there is one tubular 
opening (see 0, fig. 19). The general resemblance to such a coral 
as Montlivaltia discus, Woods, is extremely striking. 
As the description of Lamouroux is not sufficient for certain 
specific comparison I do not quote his locality. 
Loc. Oolitic: Lebisey, Ranville (/.), Luc (#.), Nantua and 
Marquise (d’Orb.), Aldinga. A small fragment from Curdies Creek 
apparently belongs to this species. 
19. DiscorUBIGERA ITERATA, nov. sp. Pl. XXXII. figs. 14, 17. 
The specimen from Aldinga is only a fragment of a colony which 
was clearly more or less discoid ; the radius of the part preserved is 
about 35 milliim. The multiserial rays must be very numerous, as 
