412 



Plate XXI. 



Fig. 1 a. Catenaria (on the Plate Vittaticella) cornuta 

 (Busk). In the bizooecial internode the moth- 

 er-zooecial, small, oval, infrascapular cham- 

 ber is seen on the boundary between the 

 mother- and the daughter-zocEcium. X 55. 



— 2 a. Catenaria (Vittaticella) elegans (Busk). The 



supra-scapular, the infra-scapular and the 

 pedal chambers are seen. A boundary cham- 

 ber (m. III.) between the mother- and the 

 daughter-zooecium. X 55. 



— 3 a. Catenaria formosa (Busk). The same cham- 



bers as iu fig. 2 a. X 40. 



— 4 a. Pterocella alata (Wyv. Th.) The mother-zooe- 



cial, flssure-like infrascapular chamber is 

 seen proximally to the small avicularium. 

 X 40. 



— 5 a. A zooecium of Calpidinm ponderosum Goldst. 



The internal cryptocj'st plate is seen and a 

 strong cryptocyst formation in the five fene- 

 strse. X 55. 



— 5 b. A zooecium of the same species, lateral view. 



The supra-scapular chamber is seen and also 

 the infra-scapular and the pedal. X 40. 



— 5 c. A bizooecial internode of the same species, 



from the basal surface. The uppermost tri- 

 angular cavity is the adzooecial supra-scap- 

 lUar chamber of the mother-zocEcium. To the 

 left is seen a supra-scapular, an infra-scap- 

 ular and a pedal chamber; to the right the 

 pedal chamber is on the other hand not vi- 

 sible; the infra-scapular is on this side divided 

 into two. X 40. 



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



basal surface. The sufra-scapular and the 

 infra-scapular chambers are seen. X 40. 



— 5 e. A bizooecial internode, from the distal end. 



X 23. 



— 6 a. Strophipora Harveyi (Wyv. Th.). The supra- 



scapular and the infra scapular chambers 

 are seen. X 40. 



— 6 b. A bizooecial internode of the same species, 



from the basal surface. The four pedal cham- 

 bers are seen. X 40. 



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



frontal surface. X 40. 



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



basal surface. X 40. 



— 6 e. A zooecium of the same species, lateral view. 



X 40. 



Fig. 6 



— 7i 



7 b. 



— 7d. 



— 9 



— 9 



b. 



A bizooecial internode, from the distal end. 

 X 55. 



Hippothoa annularis (Moll), with ooecia. On 

 the boundary between the zooecia in the 

 proximal row pore-chambers are seen for 

 communication with eventual gonozooecia. 

 X 23. 



The distal end of a zooecium of the same 

 species. X 75. 



A zooecium of the same species, lateral view. 

 Three holes are seen for communication 

 with tiie pore-chambers in a neighbouring 

 zooecium and two pore-chambers for the 

 communication with eventual gonozooecia. 

 X 55. 



A zooecium of the same species, from the 

 basal surface. On each side of the angularly 

 bent distal wall the entrance to a large 

 pore-chamber is seen. X 55. 

 The operculum of the same species. X 75. 

 Operculum common to the gonozooecium 

 and ooecium. X 200. 



Hippothoa cornuta (Busk), var. holostoma n. 

 X 40. 



A zooecium of the same form with ooecium. 

 lateral view. X 40. 



A zooecium of the same form, from the 

 distal end. X 75. 



An operculum of the same form. X 200. 

 Four zooecia of the same form, of which two 

 with ooecia. X 40. 



Operculum common to the gonozooecium and 

 ooecium. X 75. 



A zooecium of the same form, lateral view. 

 The acropetalous spine has an internal sep- 

 tum. X 55. 



An ooecium-bearing zooecium of Hippothoa 

 cornuta (Busk), var. aporosa n. lateral view. 

 The acropetalous spine has two cavities divi- 

 ded by an internal septum. X 40. 

 A zooecium of the same form, from the dis- 

 tal end. X 75. 



Three zooecia of the same form, of which 

 two with ooecia. The latter are distinctly 

 visible through the surrounding kenozooecia. 

 X 40. 



An operculum of the same species. X 200. 

 Operculum common to the gonozooecium 

 and ooecium. X 200. 



