414 



Plate XXII. 



Fig. 1 a. Flustra (Retiflustra) reticulum Hincks. X 23. 



— 1 b. A zocecium of the same species with ooeci- 



um, lateral view. X 40. 



— 1 c. The same species from the basal surface. 



The uppermost zocecium in the central row 

 is furnished with an ocecium. X 23. 



— 2 a. Flustra (Retiflustra) cribriformis (Busk), from 



the basal surface. The two uppermost zooe- 

 cia with ooecia. X 40. 



— 3 a. Onychocella sp. The two uppermost zooecia 



witli ooecia. X 40. 



— 3 b. A zocecium of the same species with ooe- 



clum. In the covering membrane of the 

 aperture is seen a simple chitinized oper- 

 culum, and in each of the two sinuses of 

 the aperture the end of a parietal muscle; 

 X 55. 



— 3 c. The same species. A zooecial operculum, 



above which an ooecial operculum. X 75. 



— 3d. An avicularian mandible of the same spe- 



cies. X 40. 



— 4 a. Electro angulata n. sp. X 40. 



— 5 a. Membranipora limosa Waters. X 55. 



— 5 ]). The distal wall of the same species with 



the peculiar spine-like processes. X 55. 



— 5 c. A spine-like process more highly magnified. 



X 200. 



— 6 a. Nellia simplex (?) Busk, from Mauritius. 



The distal part of the ooecium is furnished 

 with a cryptocyst belt. X 40. 



— 7 a. Thalamoporella cincta (Hincks). X 40. 



— 7 b. Tlie same species, lateral view. The distal 



wall and the one opesiular outgrowth are 

 seen. X 40. 



— 7 c. A transverse section through a zocecium, 



distally to the two large swellings and view- 

 ed from the distal end. The two swellings 

 and one of the opesiulse are seen. X 40. 



Fig. 7 d. The operculum of the same species. X 100. 



— 8 a. Caberiella benemunita (Busk). X 55. 



— 8 b. The same species from the basal surface. 



A transversely placed vibraculum is seen. 

 X 55. 



— 9 a. Haplopoma impressum (Moll), with primary 



zocecium. In the margin of the zocecia in- 

 ternal pore-chambers are visible. X 55. 



— 9 b. The operculum of the primary zocecium. 



X 140. 



— 10 a. Haplopoma bimucronatum (Moll), with pri- 



mary zocecium. X 55. 



— 10 b. Operculum of the same species. X 140. 



— 10 c. Operculum of the primary zocecium of the 



same species. X 140. 



— n a. Operculum of Pbrella (?) cornuta n. sp. 



X 75. 



— 12 a. A developing ooecium of Smittina Smitti 



(Kirchenp). The development of the crypto- 

 cvst of the distal zocecium has begun. 

 X 40. 



— 13 a. Trgpostega venusta (Norman). Three small 



dwarf-zooecia are seen and a larger which 

 surrounds an ocecium. X 40. 



— 13 b. The distal end of a zocecium of the same 



species. X 75. 



— 13 c. An opei-culum of the same species. X 75. 



— 13 d. The aperture of a dwarf- zocecium with 



operculum. X 200. 



— 14 a. An ooecium of Sclerodomus denticulatus 

 w (Busk), and its surroundings, seen from the 



frontal surface. X 40. 



— 15 a. A zocecium of Escharella immersa Flem. 



var. with developing ooecium. The part com- 

 mon to the zocecium and the endoooecium 

 (the »basal mark«) is seen. X 40. 



