92 

 Family: Aeteidae. 



(I'l. VI c, liji;S. li ;i-(i (1). 



The zoa'via, wliicli liavc no spines and the calcareous wall of wliicli is (icnscly 

 covered willi j)oies of dilTerent form, consist of Iwo portions inclined towards 

 one another at an angle, the lower of which is as a rule decumbent, adherent, 

 while the upper, mostly tube-shaped part is provided at its expanded end with 

 a small membranous frontal area. No cryplocyst. The diajjhragm has a structure 

 similar lo thai in the Ctenoslonicita. The heterozoivcia and (mvcui wanting. The 

 distal wall furnished with a row of uniporons rosette-plates. The colony creeping, 

 forming a meshwork of single rows of zoa-cia, from which free in-anches some- 

 times issue. 



The partly thin, thread-shaped adherent part, from which the free upright 

 part of the zocecia arises, is by Flincks compared lo a stolon bul this name can 

 only be used for a basal portion, consisting of kenozocrcia, as found within the 

 order Ctenostoniatct in the families Vesiciihtriklae, Trilicellidae, Valkeriidae and 

 Mimosellidae and within the Cheilostomcitd in the genera Chlidonia, Liriozoa and 

 Stirpaiid. In .4e/('a the whole colony is built up by autozoa'cia, and the fact, 

 that the proximal part of the zoa?cium is thin and uuich elongated, does not 

 entitle us to sj)eak of a stolon in these sj)ecies any more than in the species, 

 which Hincks refers to the genus Hippolhou. The adherent parts of two successive 

 zooecia are separated by a wall, which in Aetea dilatata is furnished with a row 

 of 7 uniporous rosette-plates, and a similar separating wall is found everywhere, 

 where one zo(]eciuni issues from another. In Aetea triincnta according to Hincks 

 new free zooecia maj' issue from the basal side of the ascending [)arl of the 

 zooecium. The calcareous wall of the zooccium is richly furnished with ])ores, 

 which in dilferent species can appear in diderenl ways. Thus, while the whole 

 calcareous surface in Aetea dilatata is furnished with round jjores, the form of 

 the pores varies in many other species at different places. For example, the distal 

 part of the zoa'cium in Aetea aiuiiiina and also the broadest part of the adherent 

 portion are furnished with small round or oval pores. In the narrower jiart of 

 the adherent portion they fuse together to longer, slit-like spots (fig. (id), and 

 in the largest part of the ascending portion (fig. 6 c) they become continuous, 

 ring-shaped interruptions, and therefore the calcareous portions ai)pear as a row 

 of free rings situated above each other, which can be isolated without great diffi- 

 culty. Sometimes however we find a short connecting branch between two succes- 

 sive rings, or a bifurcation of a single ring. Waters' has found an egg enclosed 



' 111, p. 5, Fl. I, ligs. 1—0. 



