170 MADREPORARIA. 
at an angle of 80° to 90°, and varying in importance from thickened and elongate proliferous 
corallites to subterete and tapering twigs 4. cm. long and 1 em. thick. Axial corallites 1°5 
to 2 mm. diameter and 0°5 to 2 mm. exsert, wall thick or comparatively thin. Radial coral- 
lites compressed nariform or tubo-nariform, unequal, the longer ones becoming tubular and 
proliferous. Some distance below the apex all become verruciform with a dilated wall, which 
gradually becomes reduced to a ring-shaped fold. Immersed corallites are usually wanting 
even in the older parts of the colony, but in one or two specimens, which agree closely in 
other respects, immersed corallites may take the place of those with a ring-shaped lip. 
Radial corallites 15 mm. diameter or under, and 1°5 to 3 mm. or more in length; aperture 
oval, wall varying in thickness in different specimens; always thickened some distance below 
the apex of a branch, and in some cases quite to the apex; in the latter case the wall of the 
axial corallites is also thickened. The axial corallites are provided with 12 septa, none of 
which are very prominent ; those of the radial corailites are also usually narrow, including the 
directives ; in the corallites situated some distance from the apex the second cycle is almost 
as well developed as the first. Corallum dense, even near the apex of a branch in most 
specimens ; surface and wall finely and closely echinulate. 
The species which Dana referred to M. abrotanoides is quite distimct from the type of 
Lamarck, with which the description given by M.-Hdwards agrees closely. The description 
and figure of Dana agree very well with the species here described and I have therefore placed 
the name as a synonym. It is possible that more recent authors may have taken Dana’s 
species for the true M. abrotanoides, and the synonymy is thus uncertain at present. 
There is considerable variation im this species, both in the branching and in the thickness 
of the corallite-wall. The specimens which have come under my notice fall more or less 
completely into three groups :— 
a. Branches elongate; corallite-wall thin or only slightly thickened near the apex of a 
branch, but becoming considerably thickened below. A few immersed corallites may 
or may not occur near the base of the branches. 
6. Branches shorter and more subdivided; corallites often 2°5 mm. diameter, all with 
thick wall and rounded lip. No immersed corallites. 
c. Branches thick and stunted, with short branchlets. Immersed corallites extending 
between the bases of the branchlets to near the apex. 
Indo-Pacific Ocean: Malacca, ? Fiji. 
a-e. Malacca. Capt. Belcher, R.N. [P.]. 42. 11. 28.1,5 & 6; 42. 11. 30. 20 & 25. 
? ? 40.5. 15. 28; 41. 2. 23. 30. 
h,i. ——? —? 93.4. 7. 158 & 159. 
Types. 
183. Madrepora forskali. 
Heteropora forskalhi, Ehrenberg, Corallenth. d. roth. Meeres, p. 113 (part.). 
Madrepora forskalii, Dana, Zoophytes, p. 489; M.-Edwards & Haime, Coralliaires, t. iii. p. 150; 
Klunzinger, Korallenth. d. roth. Meeres, Th. ii. p. 17, pl. iii. fig. 6, pl. v. fig. 2, pl. ix. fig. 13. 
Corallum forming dense and much-branched clumps 10 to 20 em. high and 15 to 20 cm, 
