MATTHAI— RECENT COLONIAL ASTR^ID^ 131 



Fig. 26. Qalaxea fascictdaris (Linn.), Longitudinal section through an exoccelic tentacle containing 

 a terminal and numerous sub-terminal batteries. Nematocysts II b mainly forming the terminal 

 battery; as in all species only type I in sub-terminal batteries. (201a il, Sjoli.) x 80. 



Fig. 27. Id. Transverse section of the mesoglsea ef a primary mesentery in the stomodseal region to 

 show the greatly sub-divided condition of the entocoelic pleats. (201„ ii, Sgi^.) x 633. 



Fig. 28. Galaxea musicalis (Linn.). Longitudinal section through an entocoelic and an exoccelic 

 tentacle. As in PI. 1, fig. 11, the endoderm of the tentacles lies in contact with the endoderm of the 

 body-wall. (101„ ii, sA^.) x 766. 



Fig. 29. Id. Transverse section through two mesenteries, each with a ripe egg projecting into the 

 exoccele between ; the upper part of a succeeding egg partially overlaps one of these. Vacuolated 

 appearance of column-wall endoderm and lower ends of mesenterial filaments to be noted. (101^ II, 

 s^S,.) X 766. 



Fig. 30. Leptastrea roissyana, Ed. and H. Longitudinal section through a primary entocoelic tentacle 

 with terminal battery only. (202^ il, Si25.) x 110. 



Fig. 31. Id. Transverse section through a primary mesentery and part of the stomodseal wall. Algse 

 abundant on the exoccelic side. (202,„ i, Sj^g.) x 120. 



Fig. 32. Diploasty-ea heliopora (Lam.). Transverse section through a primary mesentery at the level of 

 the stomodseum. In outline to indicate the ento- and exoccelic pleats. (104j; i, Sglj.) x 60. 



Fig. 33. Leptast7^ea roissyana, Ed. a,nd H. Nematocyst II 6. (202„ i, S226.) x 1700. 



Fig. 34. Diploastrea heliopora (Lam.). Nematocyst II from the convoluted part of a mesenterial fila- 

 ment. (104i III, S25I4.) x 950. 



Plate 4. 



Fig. 35. Faviafavus (Forsk.). Stages a — g in the development of a nematocyst I. From the ectoderm 

 of oral-disc. (202^ i, s,.) x 1500. 



Fig. 36. Id. Transverse section through principal mesentery and part of the stomodseal wall. (202^ i, 

 s,,3,.) x60. 



Fig. 37. Id. Stages a — -f in the development of a nematocyst II. From the ectoderm of oral-disc 

 (202^ I, s,.) X 1500. 



Fig. 38. Id. Nematocyst II from convoluted region of a mesenterial filament. (202^ i, 51424.) x 900. 



Fig. 39. Id. Early stages in the formation of the axis of nematocyst II. From nuclei in mesenterial 

 filament. (202^ I, s.^.) x 1500. 



Fig. 40. Id. Nematocyst III with the thread partially extruded. (202^ i, 51925.) x 900. 



Fig. 41. Favia doreyensis, Ed. and H. Transverse section through a principal mesentery and part of 

 the stomodseal wall. In the pleatal region algse are more abundant on the exoccelic side, while in 

 the non-pleatal region they occur principally on the entocoelic side. (106^ i, s^sli.) x 55. 



Fig. 42. Favia huhdensis, Gard. Transverse section through a principal mesentery and part of the 

 stomodeeal wall. (106^ i, Si2 2i.) x 80. 



Fig. 43. Favia clouei (Valen.). Transverse section through a principal mesentery and part of the 

 stomodseal wall. (304^ 11, 5,21.) x 43. 



Plate 5. 



Fig. 44. Favia doreyensis, Ed. and H. Longitudinal section through an entocoelic tentacle. Stages in 

 the development of nematocyst I in terminal battery ; and vacuolization in ectoderm and endoderm. 

 Algse scarce. (106^ i, Siylj.) x 185. 



17-2 



