476 
MR. H. N. MOSELEY OH THE STRUCTURE OF THE STYLASTERIM. 
Genus 4. Labiopora, gen. nov., H. N. M. (Type specimen in British Museum, 
mistaken by Gray for a Bryozoon, and described by him as Porella Antarctica.) 
(Proc. Zool. Soc., 1872, p. 746, plate lxiv., fig. 4). — Corallum minutely reticulate in 
texture, composed of a few rounded branches with tapering extremities. The entire 
surface covered with nariform projections, with elongate cavities, which are arranged in 
rows along the lengths of the branches, often disposed with great regularity for long 
stretches. The projections of very uniform shape and rising from the branches to 
a uniform height. All inclined in the directions of the tips of the branches. The 
elongate cavities, which are extended in the direction of the lengths of the branches, 
have a defined rounded margin at their ends, situated towards the tips of the branches, 
but gradually merge at their opposite extremities in the deep and complex hollows by 
which the surface of the coral is excavated, and which are made up of the confluences 
of cavities of adjacent nariform projections with the other irregularities of the surface. 
Dactyl opores devoid of styles ; two kinds present, larger and smaller. The nariform 
projections are the outgrown margins of the larger dactylopores, which are continued 
into the substance of the corallum from the cavities of the projections as tubular pits. 
The smaller dactylopores have mouths of the same general form as those of the larger 
ones, but with their longer diameters directed at right angles to these latter. They 
have their walls fused with those of the nariform projections, or often appear as if 
excavated in the sides of these. They are of one-third or one-fourth the dimensions 
of the larger pores. Mouths of the gastropores deeply seated in depressions at the 
bases of the nariform projections. Circular in outline. Gastropores provided with 
deeply seated styles with brush -like tips. No ampul ke in the unique specimen. Soft 
structures unknown. 
Genus 5. Spinipora, gen. nov., H. N. M. — Corallum branching. Branches rounded. 
Entire surface thickly beset with long spinous projections inclined towards the tips of 
the branches. Spines conical, grooved deeply on them sides turned towards the tips 
of the branches so as to present spout-like openings, which are the mouths of the 
larger dactylopores. Dactylopores of a smaller kind also present ; their mouths 
appear as minute oval apertures scattered over the bases and sides of the spines. 
Styles absent in the dactylopores. Gastropores deeply seated in hollows between 
the bases of the spines ; with deeply placed styles. Ampulke absent in the unique 
specimen. Dactylozooids of two kinds, the larger attached by elongate bases within 
the spout-like cavities of the larger dactylopores, incapable of retraction within the 
pores ; the smaller minute ; entirely retracted when at rest. Gastrozooids cylindrical, 
with six tentacles and four basal canals. Gonophores unknown. 
Genus 6. Allopora . — Corallum branching, but frequently not so as to form a flabellum. 
Pores in regular cyclo-systems only, excepting in A . Nobilis, where some of the systems 
are not perfected. Tendency to alternate gemmation present, but weak, and usually 
obscured by an abundant growth of ccenencliym. Cyclo- systems always scattered over 
the faces of the branches, as well as situate at their lateral margins ; often entirely 
