263 



the ooccia have a similar structure and laciv the two free, ril)-like processes found 

 in the two above-described Onchopora species. 

 Colonies from Hawlvcs Hay (Miss Jelly). 



Onchoporella bombycina (L.) Busk. 

 Carbacea bombycina Busk, Catalogue of Marine Polyzoa, 



Cheiloslomata, pag. 52, PI. 48, figs. 4—7. 

 Onchoporella bombycina Husk, Challenger, Zoology, Vol. X, Part I, p. 104. 



(t'l. Mil, ligs. 9a-9j). 



The zooecia are elongated, generally liexagonally rounded, and the large aper- 

 lure has a semi-elliptical anter and a broadly rounded, ol)ii(]uely (nilwards turned 

 [)osler, which latter is sejjarated on either side from the former hy a distinct 

 hinge-tooth. Outside each hinge-tooth we lind a ralher shorl, cyiindrically coni- 

 cal .spine, and a very small spine is situated at the distal end of the zoa'cium. 

 The large, widely open ascopore is made semilunar by a triangularly rounded 

 tongue projecting into it dislally, and the two lateral margins of this tongue are 

 continued into two sutural lines, which diverge toward the ai)erture and sometimes 

 can be traced to the corners of the poster. The ascopore seems therefore to be 

 the remains of a triangular primary sinus, the greater part of which is later filled 

 up. In the narrow marginal portion between the aperture and the distal end of 

 the zocecium we find 2 — 4 rosette-plates, which have altogether up to 6 pore- 

 areas. If there are only two plates, they are very elongated and provided each 

 with 2 — 3 areas. On the proximal side of the aperture 1 — 6 pore-areas are found 

 along each lateral margin. They are situated in a longitudinal row and may be 

 distributed on f— 4 rosette-plates, of which the longest hitherto found contain 4 

 areas. Most often an uneven number of pore-areas are found on the two sides of 

 the same zoojcium and the larger number is generallj' present on the side, which 

 is turned away from the central line of the branch. The largest number of pore- 

 areas is generallj' found on the" outer side of the marginal zooecia. 



The distal wall is bent from side to side and on either side terminates in a 

 pointed portion. Along its basal margin we find a rather dense transverse belt of 

 uniporous rosette-plates (tig. 9 g), while the distal half of each lateral wall is pro- 

 vided with an oval, multiporous plate. 



The ooecia are large, strongly arched, with low, transversely striated, radiating 

 ribs. The basal surface is provided with a more thickened central portion with 

 rib-like processes, and the proximal part of the eclooa>cium is calcified for a 

 short distance on either side of the aperture. 



The colonies arc Flustra-like, one-layered, richly branched, with rather short 



