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THE VOYAGE OF H.M.S. CHALLENGER. 
Character. — Zoarium much and irregularly branched in various directions. Branches 
subcompressed, varying in breadth from (U‘15 to *25. Zooecia at the growing extremity 
ventricose and subtubular towards the orifice ; in all other parts completely immersed, 
so that no outlines are discernible, the thickened annular orifices alone projecting from a 
level surface, which is closely and uniformly pitted. Orifice suborbicular, peristome very 
thick, annular, entire, and on it are placed from five to eight small circular avicularia on 
as many tubercular elevations. An elongate sublateral pore or fissure some distance below 
the orifice. Ooecia — % 
Habitat. — Station 190, lat. 8° 56' S., long. 136° 5' E., 49 fathoms, green mud. 
Station 162, off East Moncoeur Island, 38 fathoms, sand and shells. 
[Bass Strait, Voy. of Battles. ; tertiary fossil, Reuss; Miocene ? Tenison Woods.] 
Although Dr. Reuss describes a central pore of large size, it is not represented in his 
figure of Acropora coronata. But there can, I think, be little doubt that the present 
species is identical with the tertiary form, as well as with that described by the Rev. 
Tenison Woods from the Mount Gambier deposits, under the name of Eschar a buslcii. 
If the peculiar characters of this form be regarded as of generic value, which I think 
they might be, Reuss’ appellation Acropora would be very appropriate. 
§§ /3. Crustaceous, unilaminar. 
2. Lepralia, Johnston. 
Lepralia, Hindis, Smitt. 
,, (pars), Brit. Mus. Cat., Auctt. 
Esdiara (pars), Auctt. 
Hemeschara (pars), Busk, &c. 
Character. — Zoarium unilaminar, erect or crustaceous, and loosely or wholly 
unattached ; or adnate with the zooecia, incomplete behind. 
(i a ) Unilaminar, erect or crustaceous, free or loosely attached (hemescharan). 
(1) Lepralia celleporoides, n. sp. (PI. XVII. fig. 4). 
Character. — Zoarium unattached, sometimes one layer overgrowing another. Zooecia 
completely immersed, convex in front, separated by wide and deep sulci, at the 
bottom of which are large pores or cancelli. Zooecia broadly oval, surface entire, finely 
granular, except a very large central subreniform or orbicular pore, which in the natural 
state is closed by a delicate membrane, and has a slightly raised border. Orifice 
coarctate, rostriform. In the older cells a tubercular elevation immediately below the 
mouth. An immersed avicularium is placed in the sulcus between each pair of cells, on 
a level with the orifice, with a duck-bill shaped mandible, directed usually vertically 
upwards, but occasionally in other directions. 
Habitat. — Station 186, lat. 10° 30' S., long. 142° 18' E., 8 fathoms, coral mud. 
