94 Mr. J. J. Quelch on new Genera and 
vesiculate endotheca the series of calicinal centres are sepa- 
rated by wide ridges, formed entirely by the thin wall and 
by the convex dissepiments which stretch from the centre to 
this thin wall. 
This genus will include, besides the following new species, 
the Plerogyra Lichtensteiné of Milne-Edwards and Haime ; 
the genus Plerogyra being limited to those forms in which 
the walls are not fused together so as to form a thin lamina, 
but in which the series remain distinct with their walls sepa- 
rated, except occasionally when two free-growing ends meet 
and grow together. 
Physogyra aperta, n. sp. 
Corallum convex above; wall very thin, simple, sometimes 
almost rudimentary. Coste very slightly developed, and then 
only at the margin of the series. The series of the calicinal 
‘centres open and shallow, in no part deep and narrow ; the 
centres are often difficult to distinguish, owing to the uniform 
development of dissepiments along the series. Width of 
series about 16 millim., but at times more than 20 millim. 
The septa are 2-4 millim. apart, very thin and very projecting, 
subequal, except at the ends of series where some are very 
small, easily broken away, leaving the vesicular dissepimental 
ridges almost bare. ‘The dissepiments are thin, convex above, 
easily broken away, about 3 millim. apart from these above 
or below at the wall, closer at their inner terminations, 
forming simple, curved, wide interseptal chambers. 
Locality. Banda. 
SANDALOLITHA, nov. gen. 
Corallum compound, flattened, free, much elongated and 
very thin. Wall sparsely porous and extremely reduced; 
distinct coste, closely granulated or very finely and bluntly 
echinulate, curving towards the short axis. Calicles few, in 
the long diameter of the corallum; parent calicle very large, 
occupying the centre, forming almost the entire corallum, with 
very numerous septa, there being about seven complete cycles, 
a much larger number of cycles being developed in the long 
axis of the corallum ; smaller calicles very few, distinctly 
radiate, developing in the course of and interrupting the 
larger septa in the long axis of the parent calicle. ‘The septa 
are crowded and very long, curving towards the short axis, 
and of more or less equal vertical extent, very low, giving an 
even laminate appearance to the corallum. Synapticula well 
developed and forming strong connexions at the basal parts of 
the septa. Columella rudimentary and trabecular. 
