388 



Plate IX. 



Fig. 1 a. Electra (Heterocecium) amplectens Hincks, 

 with ooecium. The small denticles are not 

 only seen at the margin of the membranous 

 area, bat are also visible through the calci- 

 fied wall of the frontal surface. X 55. 



— lb. The frontal wall of the same species, from 



the internal surface. X 75. 



— 1 c. A variety of the same species. The lower- 



most zooecium has been regenerated. X 75. 



— 2 a. Electra zostericola (Nordm.). The uppermost 



zooecium with ooecium. X 40. 



— 2 b. Two zooecia of the same species. The up- 



per with ooecium. X 55. 



— 3 a. Callopora Dumerili (Aud.) Two developing 



ooEcia in different developmental stages. 

 X 55. 

 — ■ 4 a. Callopora aurita (Hincks). Uppermost a 

 developing ooecium is seen, lowermost an 

 ooecium in which the proximal part of the 

 ectoooecium is not calcified. X 40. 



— 5 a-h. Different developmental stages of the 



ooecium and the covering avicularium of 

 Tegella unicornis (Flera.). endo — the endo- 

 ooecium, ecto — the ectoooecium. In fig. 5 d 

 the uniporous rosette-plates, destined to 

 connect the avicularium with the zooecium, 

 are seen distally to the ooecium. In fig. 5 e 

 the first sign of the avicularium is seen as 

 a transverse ridge proximally to the mem- 

 branous frontal area. In 5 f — 5 h the avicu- 

 larium. X 40. 



— 6 a-c. Different developmental stages of the 



ooecium and the covering avicularium in 

 Tegella Sophiae (Busk). In 6 b (which is 

 younger than 6 a) distally to the developing 

 ooecium are seen two oval incisions which 

 in fig. 6 a have closed themselves. It is the 

 beginning of the two rosette- plates which 

 should connect the avicularium with the 

 zooecium. Fig. 6 c corresponds in the degree 

 of development of the avicularium with 



fig. 5 f. The two rosette-plates are seen. 

 X 40. 

 Fig. 7 a. Electra bicolor (Hincks). X 55. 



— 7 b. The same species. Reproduction of a zooe- 



cium. X 75. 



— 7 c. A transverse section through a colony. In 



two of the zooecia the distal wall with 

 rosette-plates is seen, in two the immersed 

 cryptocyst. X 75. 



— 8 a. Petalostegus bicornis (Busk). X 55. 



— 8 b. A zooecium of the same species, seen a 



little more from the side X 55. 



— 9 a. Membraniporella distans Mac Gilliv. X 55. 



— 10 a. Two zooecia with ooecia of Cri6ri7ina annn- 



lata (Fabr). The ooecia are covered by keno- 

 zooecia and on these some pore-chambers 

 are seen. X 40. 



— 10 b. A longitudinal section of the same species 



through a zooecium with ooecium. X 55. 



— 11 a-c. Three different developmental stages of 



the ooecium of Cribrilina punctata Gray. 

 X 40. 



— lid. An ooecium of the same species. The endo- 



ooecium is visible through the broken 

 ectoooecium. X 40. 



— lie. The distal end of a zooecium of the same 



species with ooecium, from the basal sur- 

 face. The pore-chambers of the zooecium 

 and kenozooecium are seen. X 40. 



— 1 1 f. Cribrilina punctata. Pore-chambers are seen 



on the three marginal zooecia, of which the 

 central abnormal one has no aperture. X 55. 



— 11 g. The same species, from the basal surface. 



Pore-chambers (p. ch). X 40. 



— lib. Sagittal section through a zooecium of the 

 , same species with ooecium. The ooecium is 



enclosed in a kenozooecium. X 55. 



— 12 a. Paellina Gattgae (Busk), with ooecia, from 



the basal surface. Both the zooecia and the 

 kenozooecia enclosing the ooecia are fur- 

 nished with pore-chambers. X 40. 



