132 PERCY SLADEN TRUST EXPEDITION 



Fig. 45. Favia doreyensis, Ed. and H. Transverse section of the straight region of a principal mesentery 

 and its filament. Note nematocysts II in endoderm. (106c i. ^w^-) ^ 150- 



Fig. 46. Favia abdita (Ell. and Sol.). Transverse section through a principal mesentery and part of 

 the stomodseal wall. (103^ I, 8^2^.) x 55. 



Fig. 47. Favia bertholleti (Valen.). Transverse section through a principal mesentery and part of the 

 stomodseal wall. (305;, i, 592;..) x 80. 



Fig. 48. Favia pentagona (Esper). Transverse section through a principal mesentery and part of the 

 stomodseal wall. (106^ iii, s^S,.) x 75. 



Fig. 49. Favia hululensis, Gard. Transverse section through a mesentery with three ova. Note germ- 

 cells. Cp. PI. 1, fig. 10 and PL 6, fig. 67. (106^ i, s„li.) x 153. 



Fig. 50. Favia ananas (Ell. and Sol.). Transverse section through a principal mesentery and part of 

 the stomodseal wall. (202;, III, S5213.) x 80. 



Fig. 51. Favia hululensis, Gard. Transverse section through oral-disc. Note ectoderm with a row of 

 oval vacuoles. (106a i. SiZ^.) x 600. 



Fig. 52. Favia •pentagona (Esper). Transverse section through oral-disc. Nematocysts I more 

 abundant in ectoderm than in any other species of Favia. Cp. with fig. 51. (106(, I, ^^Si.) 

 x650. 



Fig. 53. Id. Transverse section through column-wall near the surface of the corallum. Note wedge- 

 shaped processes of attachment in the calicoblastic layer and remarkable regularity in the 

 processes to the mesoglsea from the nuclei of both layei'S. Cp. with fig. 52. (106;, I, 4326.) x 650. 



Plate 6. 



Fig. 54. Goniastrea solida (Ed. and H.). Transverse section through a principal mesentery and part of 

 the stomodseal wall. (106/ I, 8^2^.) x 80. 



Fig. 55. Goniastrea retiformis (Lam.). Transverse section through a principal mesentery and part of 

 the stomodseal wall. Note somewhat regular arrangement of vacuoles in the endoderm in the 

 pleatal region. Algse scarce. (105a I, S3 25.) x 110. 



Fig. 56. Goniastrea pectinata (Ehrh.). Transverse section through a principal mesentery and part of 

 the stomodseal wall. (203c I. Siol?-) x 80. 



Fig. 57. Favia hululensis, Gard. Transverse section through a nematocyst III. Note membranous wall 

 and protoplasmic core. (106a I. Sie-) x 1450. 



Fig. 58. Goniastrea solida (Ed. and H.). Transverse sections a and b, through two nematocysts lie 

 passing through their axes at different levels. (106/ i, S422.) x 1450. 



Fig. 59. Id. Transverse section through the convoluted region of a mesentery. Nematocysts lie 

 arranged to form batteries. Cp. with PL 2, fig. 17. (106/ i, s^Ss.) x 1450. 



Fig. 60. Favia hululensis, Gard. Nematocyst III. The spiral of thread is only faintly visible in the 

 unextruded condition. (106a i. Sigls.) x 950. 



Fig. 61. Goniastrea retiformis (Lam.). Nematocyst III. Note narrow sac. Cp. with figs. 16 and 60. 

 (1056 ni, S4I8.) x 950. 



Fig. 62. Id. Nematocyst II. Cp. with PL 4, fig. 37/, and note narrower sac and shorter axis. 

 (1056 ni, 5484.) x 950. 



Fig. 63. Galaxea fascicularis (Linn.). Nematocyst I from terminal battery of tentacle. (201a 11, S9I1.) 

 X 1600. 



Fig. 64. Id. Nematocyst II & from terminal battery of tentacle. (201a n, S9I1.) x 950. 



