96 THE VOYAGE OF H.M.S. CHALLENGER. 
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 into 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. 
Dactylopores 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 ccenosteum from the cavities of the projections as tubular slits. 
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 ampulle in the unique specimen. Soft 
structures unknown. 
6. Spinipora, Moseley.’ 
Ccenosteum branching. Branches rounded. Entire surface thickly beset with long 
spinous projections inclined towards the tips of the branches. Spines conical, grooved 
deeply on their 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, having deeply placed styles. Ampulle 
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. 
7. Allopora, Ehrenberg. 
Ccenosteum branching, but frequently not so as to form a flabellum. Pores in 
regular cyclo-systems only, excepting in Allopora nobilis, where some of the systems 
are not perfected. Tendency to alternate gemmation present, but weak, and usually 
obscured by an abundant growth of ccenenchym. Cyclo-systems always scattered 
over the faces of the branches, as well as situate at their lateral margins ; often 
entirely sporadic in disposition. Dactylopores with a more or less rudimentary style 
’ Prelim. Report, Phil. Trans. Roy. Soc., 1878, part 2, p. 476. 
