130 PERCY SLADEN TRUST EXPEDITION 



Fig. 8. Gyphastrea semilia (Forsk.). Nematocyst II. (102;, IV, s^^^a-) x 1700. 



Fig. 9. Id. Transverse section through a primary mesentery with testis containing triangular-shaped 

 spermatozoa. (I02i, IV, s^2,.) x 350. 



Fig. 10. Id. Transverse section through a primary mesentery of a female polyp, bearing a ripe ovum 

 and two groups of germ-cells. (102;, vi, S229.) x 193. 



Fig. 11. Gyphastrea chalcidicum (Klunz.). Longitudinal section through a primary entocoelic tentacle 

 containing a terminal battery and sub-teiminal batteries. In the centre of the tentacle lay a 

 septum, which has been decalcified, and the endoderm of the tentacle has by contraction come to lie 

 in contact with the body-wall (endoderm and calicoblastic ectoderm) over the septum. (200j i, 

 Si3i.) X 180. 



Fig. 12. Gyphastrea suvadivo}, Gard. Longitudinal section through a primary entocoelic tentacle con- 

 taining a terminal battery and a pair of sub-terminal batteries. (102^ I, Si3i.) x 240. 



Plate 2. 



Fig. 13. Gyphastrea chalcidicum (Klunz.). Transverse section through a primary mesentery and part of 

 the stomodseal wall. (200;, i, Si4i2.) x 180. 



Fig. 14. Gyphastrea suvadivm, Gard. Transverse section through a primary mesentery and part of 

 the stomodseal wall. (102^ i, Si45.) x 180. 



Fig. 15. Id. Nematocyst III from convoluted region of a mesenterial filament. (102^ I, Sjlj.) x 1450. 



Fig 16. Echinopora hirsutissima, Ed. and H. Nematocyst III 6 from convoluted region of a mesenterial 

 filament. (107, 11, s^ 23.) x 900. 



Fig. 17. Id. Transverse section through convoluted region of a mesentery. Nematocysts III 6 arranged 

 in batteries. (107, 11, s^o2,.) x 115. 



Fig. 18. Id. Nematocyst II fi"om convoluted region of a mesenterial filament, its axis extending beyond 

 two-thirds the length of its sac. (107;, I, S3I1.) x 950. 



Fig. 19. Id. Longitudinal section through an entocoelic tentacle bearing a large terminal battery and 

 about six tub-terminal batteries on each side. Algae rare. (107^ I, Si2.;,.) x 105. 



Fig. 20. Id. Transverse section through a primary mesentery and part of the stomodseal wall. 

 (107, II, Sele.) x80. 



Fig. 21. Echinopora lamellosa (Esper). Transverse section through a primary mesentery and part of 

 the stomodseal wall. (107;, 11, s^^i.) x 115. 



Fig. 22. Echinopora gemmacea (Lam.). Transverse section through a primary mesentery and part of 

 the stomodseal wall. The mesentery is somewhat contracted in a radial direction. Algas few. 

 (204, II, .534,.) X 115. 



Fig. 23. Galaxea fascicidaris (Linn.). Transverse section through a primary mesentery and part of the 

 stomodseal wall. (201„ 11, Sjolj.) x 55. 



Fig. 24. Id. Transverse section through outer wall of edge-zone. Cp. with PI. 1, fig. 2, and note thick 

 ectoderm with many nuclei and ovoid bodies, and swollen endoderm with algae rare. (201a II, Ss-) 

 x600. . . 



Plate 3. 



Fig. 25. Galaxea fascicularis (Linn.). Transverse section through inner wall of edge-zone near 

 attachment of a mesentery to the outer surface of the corallum, showing calicoblastic ectoderm 

 greatly thickened with piled up nuclei. (201„ 11, 5523.) x 400. 



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