394 



Plate XH. 



FiR. 1 a. 



— 1 1). 



— 1 c 



1 d. 



1 f, 

 1 

 1 

 1 



— Ih. 



3 a. 



3 b. 



— 4b 



— 4 c 



Sternal area and aperture of Cnaliiilhi bcne- 

 costatn n. sp. (On the plate designated as 

 Cat. haslala). X 100. 



Sternal area and aperture of anotlier zoa'cium 

 of the same speiies. X 100. 

 Sternal area and aperture of <'.osliceU<t ha- 

 slala (Busk) (from Twofold Bav). The long 

 fi'ontal sinus, wliitli is not seen in tiic two 

 preceding figures, is licre distinctly visible. 

 X 100. 



A part of the sternal area of tlic same spe- 

 cies, from the internal surface. Outermost 

 the margin of the crvptocvst plate, further 

 in the frontal sinus. X 100. 

 ,A gono/.oocium of the same species, lateral 

 view. X 40. 



A gonozo(ecium of tlie same species, from 

 tlie frontal surface. X 40. 

 The distal end of another gonozooecium of 

 the same species. X 55. 



A gonozo(Ecium of Costicella soIiUa n. sj). 

 (The figure does not give a good representa- 

 tion of the structure of the sternal area). 

 X 40. 



A sagittal section through a gonozoiecium of 

 the same species. The endozoiecial ofecium, 

 formed from the distal wall and covered by 

 a keno/.oiecium is seen. X 40. 

 The distal end of a zoieeium of Scuticella 

 sacciiUila (Busk) (wrongly indicated on the 

 plate as C. saccala). X 100. 

 A trizocvcial internodc with occcium of Cla- 

 viporella (on the plate, Calpidium] geminata 

 Wyv. Thorn. X 40. 



A similar internodc, on which the frontal 

 wall of the od'cium and of the covering 

 kenozocEcium has been removed. The basal 

 wall of the endozoiecial oa-cium is seen. 

 X 40. 



A sagittal section through the gonozo(ecium 

 and the occcium of the same s])ecies. X 40. 

 A small avicularium of the same species. 

 X 00. 



Claviporella (on the plate Cal]>i(iiiiin) imsilla 

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

 mal part of each zooecium the extremely 

 small pedal chamber. X 26. 

 An internode of the same species with occ- 

 cium. X 40. 



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. 



Fig. 4d. The proximal end of a zorccium of flic same 

 species. The rudimentary pedal chambers 

 are seen. X 75. 



— 4 e. The inner wall of the pedal chamber, form- 



ing a uniporous rosette-plate. X 200. 



— 4 f. The operculum of the same species. X 100. 



— 4 g. The scapular and the infrascapular chambers 



of the same species. X 200. 



— 5a. An internode with o(ccium of I'lcrorclla (on 



the plate (.alpicliiim) rarinala (Busk). Neither 

 this nor the following figure give a satis- 

 factory representation of tlie structure of the 

 sternal area. X 40. 



— 6 a. An internode with occcium of Plerocclla (on 



the plate Calpidiutu alata (Wvv. Thorn.) 

 X 40. 



— 6 b. Sagittal section through the gonozoivciuin, 



the oiecium and the covering kenozocecium 

 of the same species. X 40. 



— 7 a. A zod'cium of C.rihricella rufa (.Mac Gilliv.), 



lateral view. The small supra-.scapular cham- 

 ber, the greatly bent infra-scapular and the 

 slightly bent pedal chamber arc seen. X 55. 

 A zoieeium of the same sjiecies, from the 

 basal surface. The supra-scapular and the 

 infra-sca])ular chambers are seen and less 

 distinctly the pedal. X 55. 

 A gonozotecium of the same species. X 40. 

 A gonozooecium of the .same species, lateral 

 view. X 40. 



7 e. A sagittal section through a gonozo(ccium of 

 the same species. X 23. 



7 f. A portion of the sternal area of the same 

 species, from the internal surface. The 

 crvptocvst plate is seen. X 100. 

 A zoiccinm of Cribricella crihraria i Busk), 

 lateral view. X 55. 



A zocccium 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. 

 HincksielUi piilrhrlld Ma])les., with iKccium. 

 X 40. 



A longitudinal section through a lateral mar- 

 gin of a zoircium of the same sjiecics. Up- 

 permost the small supra-scapular chamber 

 and lowermost the inner wall of the long 

 scapular chamber, which is connected witli 

 the zoieeium through two uni])orous rosette- 

 plates. X 75. 



9 c. A transverse section through a zooecium of 

 the same species. The extremely thick walls, 

 which separate the lateral chambers from 

 the zoojcium, are seen. X 75. 



b. 



I c. 

 'd. 



