384 



Plate VII. 



Fig. 1 a. Macropora centralis Mac Gilliv. X 23. 



— lb. The aperture of a special form of zooecium 



(avicularium ?) of the same species. X 40. 



— 1 c. Au operculum with its surroundings of the 



same species. X 40. 



— 1 d. A pore-chamber of the same species. X 40. 



— 2 a. Membranicellaria dubia (Busk), with ocecia. 



Tlie elongated hexagonal zooecia are partly 

 visible through the frontal surface,- which 

 is divided into hexagonal, rhombic areas. 

 X 17. 



— 2 b. The same species from the basal aspect 



after removal of the basal surface. The 

 cavity of the elongated zooecia is visible and 

 the hexagonal, rhombic areas of the frontal 

 surface are seen at the same time. On the 

 distal portion of each zooecium an ooecium 

 (ov.) with its oblique, basal surface is seen. 

 X 17. 



— 2 c. Zooecia of the same species with ooecia. The 



covering membrane is removed. X 17. 



— 2d. Rosette-plates of the same species. X 75. 



— 2 e. Zooecia of the same species. The separating 



walls of the elongated zooecia are visible 

 through the frontal surface, divided into 

 broad areas. X 17. 



— 3 a. Alysidium parasiticum Bvisk. A gonozooecium 



with a double-valved ocecium is seen on 

 the lowermost zooecium. X 40. 



— 3 b. A zooecium of the same species. X 75. 



— 3 c. A zooecium of the same species from the 



basal surface. The bent distal wall is seen. 

 X 75. 



— 3 d. A longitudinal section through a zooecium 



of the same species. X 75. 



— 3 e. A gonozooecium of the same species from 



the frontal ooecia-bearing surface, after the 

 removal of the ooecium, The two elongated 

 openings are seen, through whicli the ooe- 

 cial valves have been in communication with 

 the pore-chambers of the gonozooecium. X 75. 



— 3 f. A transverse section through the distal end 



of a zooecium. A row of uniporous rosette- 

 plates is (very indistincly) seen. X 75. 



— 3 g. The end of a branch of the same species 



with a cylindrical internode. X 40. 



Fig. 3 h. A gonozooecium with the ocEcial valves open. 

 X 55. 



— 3 i. An ooecial valve from the internal surface. 



X 55. 



— 3 j. A gonozooecium with ooecium, seen from the 



basal edge. X 40. 



— 3 k. A gonozooecium with developing ooecial 



valves, lateral view. A lateral pore-chamber 

 and a part of the basal one are seen. X 75. 



— 3 1. The same gonozooecium, from the basal 



edge. X 75. 



— 3 m. The stem of the gonozooecium. The distal 



wall (d. w.) and a uniporous rosette-plate 

 are seen. X 75. 



— 3 n. The stem of the gonozooecium, lateral view. 



Opposite the proximal part of, the oval de- 

 pression the oblique distal wall is seen. X 75. 



— 3 o. An oblique section through the middle part 



of the stalk-like kenozooecium, seen from 

 the basal surface. The three rosette-plates 

 of the distal wall are seen. X 75. 



— 4 a. A longitudinal section througli Celhilaria 



aiisfralis Hincks. Above the majority of the 

 zooecial chambers an ooecium (ov.) is seen. 

 X 23. 



— 4 b. A transverse section through a portion of 



the same species. The ooecial cavity (ov.) 

 and the arched rosette-plates of the lateral 

 walls are seen. X 40. 



— 4 c. A transverse section through a portion of 



the same species. The ooecial cavity (ov.) 

 and the rosette-plates of the distal wall are 

 seen. X 40. 



— 4 d. A portion of a longitudinal section of the 

 • same species, more highly magnified. A 



zooecium with two rosette-plates and an 

 ooecium (ov.) are seen. X 40. 



— 4 e. A longitudinal section through the proximal 



part of an internode of the same species. 

 ^- 4 f . A longitudinal section through au internode 

 of the same species, showing developing 

 ooecia (ov.). X 23. 



— 5 a. A row of zooecia of Cellularia fistulosa (?) 



(L.) with ooecial fissures. X 40. 



