MADREPORA. 103 
The specimens referred by Ehrenberg to H. microclados appear referable to two, possibly 
to three species. Those which he mentions as forming part of the Berlin-Museum collection 
are, with one exception, identical with M. spicifera, Dana. As already indicated by Studer, 
slight differences occur; but nothing which, in my opinion, entitles them to rank as a distinct 
species. Ehrenberg, however, also refers to a fine specimen in the cabinet of the “ Gesell- 
schaft der naturforschenden Freunde.” This specimen also is now in the Berlin Museum; it 
differs specifically from the other specimens, and is practically identical with the type of 
M. flabelliformis, Ed. & H. On comparing the various specimens with Ehrenberg’s diagnosis, 
I find that the specimen formerly in the possession of the “Ges. naturf. Freunde” agrees 
closely—so closely, indeed, that it appears to have been the specimen on which the diagnosis 
was based ; on the other hand, the remaining specimens do not conform to the description. 
Under these circumstances it appears necessary to regard the specimen in question as the 
type, and the others as M. spicifera, Dana. In this case, M. flabelliformis, Ed. & H., becomes 
asynonym. ‘The following is a description of the specimen :— 
Corallum flabellate or shallow vasiform; the part preserved consists of a frond 26 cm. 
high and 24 cm. wide above, but tapering almost to a point at the base. Under surface 
complanate ; branches laterally compressed, 12 by 8 mm., rather distantly coalescent. Surface 
almost naked, with numerous immersed corallites 0°75 to 1 mm. diameter, and a few short 
branchlets pressed mto the general plane, 1 to 1°8 cm. long and about 4 mm. thick ; each 
consists of an elongate and thick axial corallite with subimmersed radial buds. On the upper 
surface the branchlets are slender, frequently oblique and rather distant, 1 to 2°5 em. long 
and 4 or 5 mm. thick at the base. Axial corallites 1:5 to 2 mm. diameter and | to 3 mm. 
exsert, or even more ; wall not much thickened ; a few of the apices are proliferous. The 
radial corallites of the main divisions are immersed or subimmersed. At the base of the 
branchlets the corallites have the outer part of the wall short and thin, and the aperture is 
wide ; towards the apex the wall gradually becomes more elongate and labellate, and spreads 
at an angle of about 40°; length 1 to 4mm., diameter 1:5 mm. ; the wall is always thin, and 
the aperture wide and circular. Corallum fragile ; surface reticulate and strongly echinulate ; 
wall broadly striate, echinulate near the base. 
The type of M. flabelliformis, Ed. & H., consists of a fan-shaped frond 32 cm. high and 
38 em. across the broadest part. It agrees closely with the specin’en already described in the 
majority of its characters. The branchlets on the upper surface’ arise singly or in groups of 
3to6. The upper radial corallites are labellate or half-tubwlar, a little unequal, 1-3 mm. 
diameter and up to 2°5 mm. long. The surface of the corallum consists of a close vermiculate 
network with fine echinulations. All the septa are narrow, and in the immersed corallites are 
almost indistinguishable. 
Indian Ocean. 
