in the Madreporide. 291 
is well marked also in Anacropora, although I have not ob- 
served it to extend to the union near the summit of the calicle 
of the two leading septa; in this genus also these two septa 
are sometimes placed diagonally with relation to the axes of the 
branch (see fig. 2). Klunzinger (Kor. roth. Meer. 11. p. 2) 
states that in Madrepora one of these two (which he calls 
“Hauptsepta’’) has its corresponding tentacle longer than the 
other eleven tentacles. 
In Seriatopora these two septa are represented ¢n position by 
the long plate which extends from the proximal to the distal 
wall of the calicle, ¢. e. in the direction of its (here) longer 
axis; but the fact that, as Prof. Moseley has shown (Quart. 
Journ. Microsc. Sci. n. s. xxil. p. 392), six primary septa 
are present without counting this, seems to favour Milne- 
Edwards and Haime’s view, that this plate is columellar, 
not septal, in origin—in which case Sertatopora would 
differ from the Madreporide in having its primary septa 
wholly distributed to the right and left of a dorso-ventral line. 
Budding or Fission in Madrepora ?—Prof. Studer, in his 
paper on Budding and Fission in the Madreporaria (Mitth. 
naturf. Ges. Bern, 1880, p..3), surmises (p. 14) from ap- 
pearances that in the Madreporide (he evidently refers only 
to Madrepora, as Montipora has no apical calicle) the new 
ealicles are really formed by fission or lateral gemmation from 
the margin of the apical calicle, which he thinks sends out 
curved bulges from its margin. All the evidence I have 
gathered myself from Madrepora is rather in favour of the old 
view that the buds are formed from the sides of the wall 
of the apical calicle in this genus. 
EXPLANATION OF PLATE XI. 
Fig. 1. Anacropora Forbest, the chief specimen, seen somewhat from 
above. Natural size. 
Fig. 2, Ditto, part of a main branch of the same specimen, showing cha- 
racters of adult calicles and of the exterior of the ccenenchyma, 
x 6 diameters. 
(Note that one calicle has the main primary septa dorso- 
ventral, the other diagonal in position.) 
Fig. 3, Ditto, vertical section of main branch of the same specimen, 
showing :—a, axial; 6, superficial cenenchyma; and e, longitu- 
dinal section of a calicle. X 6 diameters. . 
Fig. 4. Ditto, basal end of detached branch, showing the renovation of 
the stump by the emergence of the loose axial coenenchyma and 
the formation in this coenenchyma of young calicles. Xx 8 dia- 
meters. 
Fig. 5, Ditto, apex of branch of chief specimen, showing the loose texture 
of the ccenenchyma at this point and the formation (as in 
fig. 4) of young calicles from this loose ceenenchyma. The view 
selected shows an unusually regular longitudinal series of young 
calicles, x 3 diameters, 
