25(5 



iixis of llu' zodriimi. The supra-scapiilni- clKimlxT is a very small, low cavity 

 willi a lriani;ularly rounded o|n'iiing situated distally to tlio inner part of tlic 

 aviculariuni. The inlVa-seapular chaniher lias an oval oj)enini^ and is situated 

 proxinially to the I'ronlal wall of the aviculariuni. It is principally in coninuini- 

 calion with the zotrciuni, IVoni wliicii it is only se|)araled by the small proximal 

 wall of the aviculariuni. 'I'lie narrow, likewise rrontal, pedal chamlier. which in 

 the single zod'cia may attain hall' the length of the latter, is situated proxinially 

 and a little Irontally to the infra-scapular chamber. There is a small, oval bound- 

 ary chamber (m. HI) on the bi-zoo-cial inlernode, and the pedal chamber on the 

 adzo(rcial side of the daughter-zoa'cium is very short, sometimes merely oval. 



The ooecium. The gonozonecium is as in the preceding species a single zoa*- 

 cium. The proximal part of its operculum is covered by a thin, labiate process 

 with a straight margin, and its avicularia differ from the ordinary zon'cia in 

 having the mandible situated in their roof, so that it forms a right angle with 

 the longitudinal axis of the gonozocecium, while in the ordinary zo(t>cia it is 

 parallel with this axis. The covering zocrcium has distally to the aperture of 

 the gonozooeciuni a rather large, irregularly rounded fenestra, on either side of 

 which we find a long curve of u|) to 20 small, round spots, which corresiiond 

 to the continuous belt in the i)receding species. 



Form of colony. Uni- and bi-zoo'cial intcrnodes alternate in such a way, 

 that two bi-zo(ecial internodes are often separated by two or several single 

 zooccia. 



Colonies from Twofold Hay, St. 16:5 A, Challenger. The form described essen- 

 tially corresponds with Ikisk's typical specimen from Bass Straits, which how- 

 ever differs in having larger, somewhat ascending and somewhal Irontally turned 

 avicularia. 



Catenaria cornuta (Husk). 



Catenicella cornuta Husk, Voyage of Hattlesnake, I, pag. 'MM, Catalogue of 



Marine Polyzoa, Cheilostomata, pag. 11, HI. X, figs. 1, 2. ."i. 



(V\. Xm, figs. 5a, .■)!), 1^1. XXI, Hi;. 1 a). 



The zooecia, the breadth of which may be contained about twice in the 



length, have a frontal surface almost as strongly arched as the basal surface and 



on either side a narrow marginal ridge, which bounds the pedal chamber basally. 



The lateral chambers. In the examined colonies it is only in a smaller 



number of zoiecia that the scajiular chamber is on one side developed as an 



aviculariuni, directed outwards and somewhat basally. Such a chaml)er may be 



found not infrequently on :, daughter-zoacium, the corresponding mother-zouicium 



