214 Proceedings of the Royal Society of Victoria. 



twice as large as the normal ones, also by the very regular 

 imbricate arrangement of the small zooecia, and the form of the 

 vibraculum. Since I determined this species I found in the 

 Jimmy's Point deposit some fragments of zooaria which agree 

 exactly with the recent form, and show on the margin the 

 characteristic large zooecia. 



S. parti punctata, nov. sp. (PI. XXIV., Fig. 4). 



Zooecia discoid, 5 mm. in diameter, very convex, nearly hemis- 

 pherical. Zooecia irregularly hexagonal, 0.3 mm. in diameter, 

 the upper angles being rounded. Thyrostome arched above, 

 proximal margin sometimes slightly incurved and having a con- 

 vexity below. The two pores in the calcareous front wall are 

 hardly ever perceptible through the membranous layer. Vibrac- 

 ular cells ovoid, much longer than broad, closely punctate, but 

 the punctures are confined to an oval area, the extreme proximal 

 portion and sides being smooth, with a projection at each upper 

 angle ; vibracula very long, slender, flexible and minutely ringed. 

 In an incinerated specimen the proximal margin of the thyros- 

 tome is seen to have a broad mucro or projecting plate ; the pores 

 are stellate. In some zooecia near the margin the mucro is of 

 dilferent construction, it is triangular, with the sharp point 

 projecting, and it is apparently connected with the front wall 

 only at each proximal angle, below the level of the zooecial front 

 wall, leaving a narrow space or slit between them, and there is a 

 raised ridge above the thyrostome. In the zooecia on the 

 extreme margin the calcareous front wall has, instead of two 

 small pores, two large lenticular openings, causing them to 

 assume an appearance similar to that of Caleschara denticulata. 



Locality. — Wollongong, N.S.W. (T. Whitelegge). 



This is separated from the other forms by the mucro in the 

 thyrostome, the very long slender vibracula, and the form of the 

 front wall of the marginal zooecia. 



The three following species from South Australia have not 

 been described before, and I have recently found one of them 

 fossil. 



S. hexagonal is, nov. sp. (PI. XXIV., Fig. 5). 



Zoarium discoid, 8 to 15 mm. in diameter, slightly raised in 

 the centre. Under surface with r.uliatin" and bifurcating I'idees 



