300 



The colonies bifurcated, with fairly broad, compressed, two-layered branches. 

 Two colonies from Victoria. 



Hasw. auricalata Busk* which this author with some hesitation refers to the 

 genus Haswellia, doubtless belongs to this genus and is most nearly related to Hasw. 

 australiensis. As in this species the bridge dividing the suboral opening from the 

 secondary aperture is provided with two small avicularia (PI. XIX, fig. 17 a). I 

 have examined a fragment from the Challenger station 135 c. 



Gephyrophora polymorpha Busk. 

 Gephyrophora polymorpha Busk, Challenger, Zoology, Vol. X, Part I, p. 167, 



PI. XXXIV, fig. 2. 

 Schizoporella polymorpha Waters, Challenger, Zoology, Vol. XXXI, Part III, 



p. 29, PI. II, figs. 21—24. 



The zooecia, usually tongue- or lyre-shaped, are fairly strongly arched, sepa- 

 rated by distinct sutural furrows and provided with fairly densely placed, short 

 pore-canals with a large inner opening. The well-chitinized operculum which is 

 provided with two muscular dots is of an oval outline and the small accessorial 

 part has a rounded poster, which is separated from the anter by a not very sharp 

 bend on each side. The hinge-teeth are well-developed. The two lateral halves of 

 the low, ring- or wall-shaped peristome are connected with each other by a strongly 

 projecting, compressed arch, formed by the coalescence of two originally distinct 

 processes, each bearing a large avicularium. Its central part which separates the 

 points of the two avicularia has in most zooecia the form of a large, projecting, 

 quadrangular plate. The perforation lying between the bridge and the proximal 

 part of the aperture corresponds to the peristomial pore in Haswellia and as in 

 the species of that genus is much larger»in the ordinary zooecia than in those 

 bearing ooecia. The distal wall and the lateral walls, which are thin, are provided 

 with a large number of scattered, uniporous rosette-plates. 



The ocecia, which are present in very large number, have when seen from 

 the surface of the colony a similar appearance as in the two species described 

 above, appearing as large, indistinctly marked off swellings which are either pro- 

 vided with pores over their whole surface or do not have these on a median part. 

 They are however considerably more elongated than in the species of the genus 

 Haswellia and in fact have quite a different structure. Thus, as Waters has 

 shown, their zocecial half is immersed into the cavity of the zooecium itself. They 

 have an unusually elongated form for ooecia and a thick cryptocyst layer is 



' 8, p. 173. 



