392 



Plate XI. 



Fig. 1 a. Scuticella plagiostoma (Busk). The lateral 

 chambers are furnished with their membra- 

 nous walls. X 23. 



— 1 b. A bi-zooecial internode of the same species, 



from the basal surface. Between the two 

 zooecia uppermost the adzooecial supra- 

 scapular chamber of the mother-zooecium 

 and lowermost its adzooecial pedal chamber. 

 The scapular and the infra-scapular cham- 

 bers are united or incompletely separated. 

 X 40, 



— It. The zooecium which arises from the mother- 



zooecium of the bi-zooecial internode, from 

 the basal surface. The floor of the two 

 supra-scapular chambers is seen uppermost, 

 whilst the membranous cover is removed. 

 The latter is seen in fig. 1 a. The two infra- 

 scapular chambers are also shown. X 40. 



— 1 d. A part of the same zocEcium, from the sur- 



face furnished with the small avicularium. 

 The infrascapular and the pedal chambers 

 are seen. X 40. 



— 1 h. A part of the same zooecium, from the sur- 



face furnished with the large avicularium. 

 The infrascapular chamber (on the basal 

 surface) is seen and also the pedal; to the 

 left of the tip of the avicularium the floor 

 of the supra-scapular chamber. X 40. 



— 1 e. The daughter-zooecium of a bi-zocecial inter- 



node, from the external surface. Uppermost 

 the unseparated distal chambers (the scapu- 

 lar and the infrascapular), and under them 

 the pedal chamber of the daughter-zooecium 

 and the adzooecial pedal chamber of the 

 mothei'-zooecium. (see fig. 1 b.). X 40. 



— If. The mother-zooecium of a bl-zocecial inter- 



node. Uppermost the two unseparated cham- 

 bers and under these the pedal chamber. 

 X 40. 



— 1 g. The zooecium which arises from a daughter- 



zooecium, from the internal surface (i. e. 

 opposite an avicularium) (see fig. 1 a.). Up- 

 permost the distal unseparated chambers 

 and below the pedal. X 40. 



— 1 i. The same zooecium, from the other surface. 



The corresponding chambers are seen. X 40. 



— 1 n. A sagittal section through a zooecium of 



Scuticella plagiostoma (Busk). The angularly 

 bent distal wall (d. w.) and the cryptocyst 

 plate (c. pi.) are seen. X 40. 



— 1 k. A gonozooecium of Cat. plagiostoma, var. 



setifera. X 23. 



— 1 1. A gonozooecium of the same form, lateral 



view. X 23. 



— 1 m. A gonozooecium of the same form, from the 



basal surface. X 23. 



— 1 j. The separating wall between the covering 



kenozooecium and the small spinous basal 

 chamber. X 40. 



Fig. 1 o. An old bi-zooecial internode of Scuticella 

 plagiostoma, v. setifera. The aperture is clos- 

 ed by a calcified plate, and this is further 

 connected with a cryptocyst which is placed 

 inside the sternal area and may finally form 

 a continuous cover inside the last. X 40 



— 1 p. Another old bi-zooecial internode of the 



same form. X 40. 



— 2 a. A zooecium of Scuticella Wilsoni (Mac Gil- 



liv.). On each side of the sternal area a large 

 infra-scapular chamber is seen. c. pi. crypto- 

 cyst plate. X 40. 



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



To the left the infra-scapular chamber and 

 to the right the supra-scapular and the 

 pedal. X 55. 



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



basal surface. The whole basal surface is 

 occupied by the supra-scapular and the 

 pedal chambers. X 55. 



— 2d. The proximal end of the sternal area of the 



same species. The bridge between the two 

 central fenestrse is not yet completed and 

 its end is uncalcified. X 75. 



— 2 f. The same part of a third zooecium. The 



bridge between the two fenestrae is for the 

 most part uncalcified. X 75. 



— 3 a. A zooecium of Scuticella amphora (Busk), 



lateral view. To the left the infra-scapular 

 chamber, to the right the supra-scapular 

 and the large pedal chamber. X 55. 



— 3 b. A zooecium of the same species, from the 



basal surface. The supra-scapular and the 

 pedal chambers are seen. X 55. 



— 3 c. A zooecium of the same species with a very 



large avicularium. To the left the supra- 

 scapular and the infra-scapular chambers. 

 X 55. 

 I- 4 a. A zooecium of Scut, urnula (Mac Gilliv.), 

 lateral view. The supra-scapular, the infra- 

 scapular and the pedal chambers are seen. 

 X 55. 



— 4 b. A zooecium of the same species, from the 



basal surface. The same three chambers are 

 seen. X 55. 



— 5 a. A gonozooecium of Scut, margaritacea (Busk). 



X 40. 



— 5 b. The same gonozooecium, lateral view. X 40. 



— 5 c. The same gonozooecium, from the basal sur- 



face. X 40. 



— 6 a. A gonozooecium of Scut, ventricosa (Busk). 



X 40. 



— 6 b. The same gonozooecium, lateral view. X 40. 



— 7 a. A gonozooecium of Scut, maculata (Busk). 



X 23. 



— 7 b. The same gonozooecium, lateral view. X 23. 



— 7 c. The sternal area of the gonozooecium and 



the two spines, more highly magnified. The 

 small cryptocyst plate is seen. X 40. 



