376 



Plate VI. 



Fig. 1 a. Crateropora falcata n. sp. X 23. 



— 2 a. Siphonoporella nodosa Hincks. X 40. 



— 2 b. The same species from tlie basal surface. 



X 40. 



— 3 a. Siphonoporella delicatissima (Busli). The 



covering membrane is removed. X 40. 



— 3 b. A zooecium of tlie same species, more highly 



magnified. X 75. 



— 3 c. A zocecium of the same species. As a great 



part of the frontal cryptocyst has been re- 

 moved, the proxiraally directed part of the 

 polypide tube can be seen. X 75. 



— 3d. The same species from the basal surface. 



The polypide tube is visible. 



— 4 a. Ldbiopora crenulata n. sp. X 23. 



— 5 a. Thalamoporella granulata, var. stapifera n. 



X 40. 



— 5 b. A gonozooecium of the same species, the 



ooecium of which has been removed. X 40. 



— 5 c. Spicula of the same form. X 200. 



— 5 d. Two zooecia of the same form, seen from 



the basal surface. 



— 5 e. A distal wall of the same form. 



— 6 a. Thalamoporella Rozieri (Aud.), var labiata n. 



X 55. 



— 6 b. The same form, from the basal surface. X 40. 



— 6 c. A zocecium of the same species, from that 



lateral surface which is nearest to the deep- 

 est opesiular outgrowth. X 40. 



— 6 d. A zooecium of the same species, from the 



other lateral surface. X 40. 



— 6 c. The distal end of a young zooecium of the 



same form. The lip is not developed. X 55. 



— 6 f. The distal end of an older zooecium with a 



fully developed lip. X 55. 



— 6 g. The distal end of an older zooecium with 



operculum. X 55. 



— 6h. The operculum of the same form. X 100. 



— 6 i. A distal wall of the same form, which is 



exceptionally furnished with two multi- 

 porous rosette-plates. X 40. 



Fig. 6 j. A distal wall of the same form with a single 

 multiporous rosette-plate. X 40. 



— 6 k. Spicula of the same form. X 200. 



— 7 a. Thalamoporella lioticha (Ortm.). X 23. 



— 7 b. The distal end of a zooecium of the same 



species. X 40. 



— 7 c. Spicula of the same species. X 200. 



— 7 d. A series of zooecia of the same species with 



ooecia, lateral view. X 23. 



— 7 e. A series of zooecia of the same species with 



ooecia, from the frontal surface. X 23. 



— 7 f . A gonozooecium of the same species, with 



developing ooecium. X 40. 



— 7 g. A schematic longitudinal section through 



the distal end of a gonozooecium with oce- 

 cium of the same species. 



— 7 h. An ooecium of the same species ; as its frontal 



half is cut away, the operculum of the gono- 

 zooecium can be seen. Lowermost the pro- 

 truding ooeclal operculum. X 40. 



— 7 i. The same species from the basal surface. 



The descending cryptocyst divides the zooe- 

 cium into a smaller distal chamber and a 

 larger proximal. The basal wall shows in 

 every zooecium a uniporous rosette-plate or 

 a corresponding opening. X 23. 



— 7 j. A zooecium of the same species, from one 



of the lateral surfaces. X 23. 



— 7 k. A zooecium of the same species, from the 



other lateral surface. X 23. 



— 7 1. An avicularium of the same species- X 40. 



— 7 m. A distal wall of the same species. X 40. 



— 7 n. A gonozooecial operculum connected with 



the appertaining ooecial operculum. X 40. 



— 7 o. The same two opercula in another position. 



X 40. 



— 7 p. The distal end of a zooecium of the same 



species after the removal of the basal sur- 

 face. The independent basal wall of the 

 polypide tube is seen. X 40. 



