394 



Fig. 1 a. Sternal area and aperture of Costicella bene- 

 costata n. sp. (On the plate designated as 

 Cat. hastata). X 100. 



— lb. Sternal area and aperture of another zooecium 



of the same species. X 100. 



— 1 c. Sternal area and aperture of Costicella ha- 



stata (Busk) (from Twofold Bay). The long 

 frontal Sinus, which is not seen in the two 

 preceding figures, is here distinctly visible. 

 X 100. 



— 1 d. A part of the sternal area of the same spe- 



cies, from the internal surface. Outermost 

 the margin of the cryptocyst plate, further 

 in the frontal sinus. X 100. 



— 1 f . A gonozooEcium of the same species, lateral 



view. X 40. 



— 1 g. A gonozooecium of the same species, from 



the frontal surface. X 40. 



— 1 j. The distal end of another gonozooecium of 



the same species. X 55. 



— 1 k. A gonozooecium of Costicella solida n. sp. 



(The figure does not give a good representa- 

 tion of the structure of the sternal area). 

 X 40. 



— 1 h. A sagittal section through a gonozooecium of 



the same species. The endozooecial ooecium, 

 formed from the distal wall and covered by 

 a kenozooecium is seen. X 40. 



— 2 a. The distal end of a zooecium of Scuticella 



sacculata (Busk) (wrongly indicated on the 



plate as C. saccata). X 100. 



A trizooecial internode with ocecium of Cla- 



viporella (on the plate, Calpidium) geminata 



Wyv. Thom. X 40. 



A similar internode, on which the frontal 



wall of the ooecium and of the covering 



kenozooecium has been removed. The basal 



wall of the endozooecial ooecium is seen. 



X 40. 



— 3 c. A sagittal section through the gonozooecium 



and the ooscium of the same species. X 40. 



— 3d. A small avicularium of the same species. 



X 00. 



— 4 a. Claviporella (on the plate Calpidium) pusilla 



Wils. Two zooecia, lateral view. In the proxi- 

 mal part of each zooecium the extremely 

 small pedal chamber. X 26. 



— 4 b. An internode of the same species with ooe- 



cium. X 40. 



— 4 c. The distal end of a zooecium of the same 



species, from the basal surface after the 

 removal of the basal wall. The suture in 

 which the two spines meet is not seen in 

 this figure, but on the uppermost zooecium 

 in fig. 4 b. X 75, 



Plate XII. 



Fig. 4d. 



- 3 a. 



3 b. 



4e. 



4 f. 



5 a. 



— 6 a. 



— 6 b. 



— 7 a. 



— 7 b. 



— 7 c. 



— 7d. 



— 7e. 



— 7 f. 



— 8 a. 



— 8 b. 



— 8 c. 



— 9 a. 



— 9 b. 



9 c. 



The proximal end of a zooecium of the same 

 species. The rudimentary pedal chambers 

 are seen. X 75. 



The inner wall of the pedal chamber, form- 

 ing a uniporous rosette-plate. X 200. 

 The operculum of the same species. X 100. 

 The scapular and the infrascapular chambers 

 of the same species. X 200. 

 An internode with ooecium of Pterocella (on 

 the plate Calpidium) carinata (Busk). Neither 

 this nor the following figure give a satis- 

 factory representation of the structure of the 

 sternal area. X 40. 



An internode with ooecium of Pterocella (on 

 the plate Calpidium) alata (Wyv. Thom.) 

 X 40. 



Sagittal section through the gonozooecium, 

 the ooecium and the covering kenozooecium 

 of the same species. X 40. 

 A zooecium of Cribricella rufa (Mac Gilliv.), 

 lateral view. The small supra-scapular cham- 

 ber, the greatly bent infra-scapular and the 

 slightly bent pedal chamber are seen. X 55. 

 A zooecium of the same species, from the 

 basal surface. The supra-scapular and the 

 infra-scapular chambers are seen and less 

 distinctly the pedal. X 55. 

 A gonozooecium of the same species. X 40. 

 A gonozooecium of the same species, lateral 

 view. X 40. 



A sagittal section through a gonozooecium of 

 the same species. X 23. 

 A portion of the sternal area of the same 

 species, from the internal surface. The 

 cryptocyst plate is seen. X 100. 

 A zooecium of Cribricella cribraria (Busk), 

 lateral view. X 55. 



A zooecium of the same species, from the 

 basal surface. X 55. 



A portion of the sternal area of the same 

 species, from the internal surface. The crypto- 

 cyst plate is seen. X 100. 

 Hincksiella pulchella Maples., with ooecium. 

 X 40. 



A longitudinal section through a lateral mar- 

 gin of a zooecium of the same species. Up- 

 permost the small supra-scapular chamber 

 and lowermost the inner wall of the long 

 scapular chamber, which is connected with 

 the zooecium through two uniporous rosette- 

 plates. X 75. 



A transverse section through a zooecium of 

 the same species. The extremely thick walls, 

 which separate the lateral chambers from 

 the zooecium, are seen. X 75, 



