16 GENERAL REMARKS. 
A. Corallum horizontal or obliquely foliate, without proper branches above. 
B. Corallum horizontal or oblique, with erect or ascending branches above, forming 
clumps with concave or convex top—vasiform or cespitose. 
C. Corallum fastigiate ; branches erect, much or closely subdivided ; corallites short and 
round nariform. 
D. Corallum arborescent ; branches evenly covered with proliferous branchlets and 
clusters. 
E. Corallum arborescent or fruticose ; branches either not proliferous or unevenly so. 
F. Corallum consisting of a few long stems from a common base, simple or rarely 
branched. 
G. Corallum composed of erect plates in place of proper branches; no distinct apical 
corallite. 
Milne-Edwards and Haime divide the genus into two sections—Fasciculate, with radial 
corallites, and Distiche, with lateral corallites; only one species is referred to the latter 
section. The Fasciculate are divided into five primary divisions, based chiefly, but not 
entirely, on habit :— 
A. Corallum arborescent ; corallites short or moderately prominent, not elongate and 
spiniform. 
Corallum arborescent ; corallites tubular and very long. 
Corallum cespitose, in the form of rosettes or tufts, rounded above. 
. Corallum corymbiform or subvasiform. 
Yow 
Corallum foliaceous and little proliferous. 
The divisions A and B correspond roughly, but not exactly, with Dana’s divisions E, C, 
and D respectively. The divisions C and D correspond similarly with Dana’s division B ; 
whilst E is formed by the fusion of divisions A and G of Dana. The plan on which Milne- 
Edwards and Haime subdivided these main groups is, however, quite different from that of 
Dana. The form of the radial corallites is rarely employed, but instead the next smaller 
groupings depend on the condition of the coenenchyma, the degree to which the branches 
coalesce, the incrusting or pedicellate character of the base, &e. The subdivision need not be 
followed further for present purposes. 
Klunzinger, in his studies of the Red-Sea Corals, has adopted quite a different classifi- 
cation of the species of that region, though it is questionable whether he would not have 
considerably modified his system, had it been necessary to include all the described species. 
The following table gives the main features of his scheme : — 
A. Axial corallites 4 to 6 mm. diameter. 
a. Aperture of radial corallites central, margin more or less rounded above ; wall 
echinulate or granular, not striate. 
6. Aperture of radial corallites oblique. 
