REPORT ON THE REEF-CORAILS. 189 
This genus is extremely close to the fossil genus Litharea from which it is distinguished 
by the trabeculate, perforated septa, the surfaces of which are nearly smooth within, and 
by the prominent columella and the paliform spinules. It is distinguished from Goniopora 
by its slightly developed, subcircular wall, which is not elevated to form strong, distinct, 
trabeculate lamin, by the equal or subequal, well-developed septa with distinct, wide and 
deep interseptal spaces, and by the paliform spinules which are more distinct on the central 
parts of the corallum than on the exterior. From Rhodarea it is distinguished by the 
‘slight development of the wall, by the well-developed distinct septa and interseptal spaces, 
by the abundant columella, and the indistinct paliform spinules. 
Tichopora tenella, n. sp. (Pl. XI. figs. 1-1a). 
Corallum extremely porous, somewhat elevated or ovoid, rounded above, and thicker 
than at the basal part where it incrusts and sometimes surrounds nodules of foreign 
matter. Gemmation rapidly taking place in the open spongy tissue enclosed between 
the walls of three or four adjoining calicles. Wall extremely porous and fragile, so as to 
be very easily broken away, often quite thin, scarcely raised ; the line of union generally 
apparent externally between the calicles, but very indistinct in section. Calicles from about 
5 to 6 mm. wide, quite shallow, nearly circular, sometimes oval or subpolygonal. Three 
cycles complete, a fourth occasionally represented in the larger cups. Septa thin, forming 
regularly perforated or trabeculate laminze quite distinct in section, very echinulate 
exteriorly, but sparsely so deep down in the interseptal chambers. Pali, consisting of six 
irregular projections placed before the secondaries, scarcely distinct from the trabeculate 
spinulose ends of the columella, which forms a marked projection in the centre of the 
ealicles, 
This species, though different in essential structure, has a very close external 
resemblance to Litharxa websteri, and might easily ‘be mistaken for a recent form of that 
species. Only a single small specimen was obtained. 
Samboangan, Philippines. 
Locality. 
Genus 7. Alveopora, Quoy and Gaimard. 
, Wy 
Alveopora (pars), Quoy and Gaimard, Voy. de l’Astrol., Zooph., p. 238, 
Milne-Edwards and Haime, Cor., iii. p. 193. 
Duncan, Rev. Madrep., p. 190. 
” 
” 
A single species of this very interesting genus was obtained. 
