168 THE VOYAGE OF H.M.S. CHALLENGER. 
5. Turbinaria peltata (Esper.) 
Madrepora peltata, Esper, Pflanz. Forts., i. p. 27, Madrep. pl. xlii. 
Turbinaria peltata, Milne-Edwards and Haime, Cor., iii. p. 165. 
A small and very typical example of this exceedingly well-marked species was 
obtained. 
The recularly cup-shaped form of the young specimens of this species soon becomes 
lost, owing to a central development of coenenchyma which tends to fill up the cavity, 
while the edges of the colony become variously and irregularly contorted and _plicate. 
By the coalescence of opposite folds, large and unequal, bifacial plates and branches are 
formed, which possess a uniform thickness throughout, and often attain to a very great 
height. 
Locality.—Somerset, Cape York, shore. 
6. Turbinaria equalis, n. sp. (Pl. VIL figs. 3-8a). 
Corallum consisting of narrow, rather thick plates, evenly covered on both sides with 
calicles. Calicles circular, not crowded, from 2 to 3 mm. apart, very small, having a 
diameter of from 1 to 1°5 mm.; superficial, the fossa being filled up with the septa, the 
proximal part of the wall not raised, the calicles being nearly even with the surface, having 
the opening directed upwards at right angles; septa generally from sixteen to twenty, 
often with a few rudimentary ones, thin, delicately spinulous, projecting quite to the centre 
and filling up the cavity. Columella very rudimentary, consisting of one or two papillee, 
generally absent. Ccoenenchyma dense; surface not striate nor echinulate, extremely 
granulated. 
Only a fragment of a specimen of this species is in the collection. It is a narrow, 
twisted plate, having a basal thickness of 7 mm. It seems to have much the same habit 
as Turbinaria bifrons, Briiggemann, but differs in essential characters from that species. 
It is probable that in both species the bifacial development of the calicles is due to 
flexure and fusion of the fronds in the early stages of growth. In Turbinaria bifrons 
the proximal parts of the oblique cups are much thickened and raised; and the cups, 
though rather shallow, are not superficial, but present an open cavity filled up at the 
base by a well-developed columella. 
Locality.—Wednesday Island, Torres Straits, 8 fathoms. 
7. Turbinaria stellulata (Blainville). 
Astreopora stellulata, Blainville, Man. d’Actin., p. 383, pl. lx. fig. A. 
Corallum massive, with an evenly and finely porous surface; very heavy,the coeonenchyma 
being of a dense texture throughout, though much perforated. Calicles rather small, 
