596 
G. HERBERT FOWLER. 
DESCRIPTION OF PLATES XL, XLI, and XLII, 
Illustrating Mr. G. Herbert Fowler’s Paper on “The Anatomy 
of the Madreporaria.” 
b. w. Cut edge of internal body-wall. ch. Calycoblast layer. Cal. Ccelen- 
teron. C. or Col. Columella. Cos. Costa. D. “ Directive 55 septum and 
mesenteries. Ed. Ectoderm. En. Endoderm. En. S. Entoseptum. Ex. S. 
Exoseptum. M. or Mes. Mesentery. M'. “Peripheral” part of mesentery. 
M. D. Mouth-disc. Me. Mesoderm. Me'. Mesenterial muscles. M. F. Me- 
senterial filament, m. long. Longitudinal muscles, m. obi. Oblique muscles. 
n. Nematocyst. Pe. Pedicle. S. Septum. St. Stonodseum. Te. Tentacle. 
Th. Theca. 
Fig. 1. — Section through two quarters of Flabellum, diagrammatic, the right 
alf showing the primary and secondary mesenteries attached to the stomo- 
dseum, taken along the line b, Fig. 2, the left being lower down in the polyp, 
where the mesenteries have all developed filaments, taken along the line c, 
Fig. 2. A. Exoccele. B. Entoccele. i, ii, iii. Orders of septa and mesen- 
teries. Corallum coloured deep black throughout the figures. 
Fig. 2. — Diagrammatic section along the line a , Fig. 1, i. e. in an exocoele, 
so that the external face of the mesentery is seen flat, while the mouth-disc 
and internal body-wall are cut. The contortions of the free edge of the 
mesentery are omitted. 
Fig. 3. — View of half of the corallum of Flabellum, showing the relations 
of pedicle, theca, and septa, and the incomplete union of the septa marked x, 
in Fig. 1 into a columella. 
Fig. 4. — Portion of the lip of the calyx of Flabellum, viewed from the 
exterior by transmitted light, to show the grooves, i, ii, iii, corresponding to 
the septa of those orders, with the lines of growth of the theca curving 
upwards at those points. 
Fig. 5. — Primary mesentery and base of primary tentacle of Flabellum, 
showing the direction of the muscles, contortions of the free edge omitted. 
Fig. 6. — Section along the line a. Fig. 2, from a full-grown specimen, with 
the layer of calycoblasts between mesoderm and theca. 
Fig. 7. — Similar section through the internal body-wall of a younger polyp, 
in which the calycoblasts are much better marked. 
Fig. 8. — Section through the tissues clothing the septum of a young 
Flabellum. 
Fig. 9. — Section through the wall of a tentacle, including one complete 
“ battery.” 
Fig. 10. — Section through a mesenterial filament of Flabellum. 
