6 



spongy texture of large rounded granules, with pores (one or 

 two) between them. Diameter, about 10 millimetres ; height, 

 about 4. 



Dredged in April, 1857, by W. S. MacLeay, at 70 to 80 

 fathoms, off Cape Three Points, and Port Stephens, N.S/W. 

 About a dozen specimens are in the Macleayan Museum. 



The size, thickness, and the peculiar spongy surface of this 

 form would distinguish it without a knowledge of the cells, 

 which are also different from any of the species described. 



Fossil Species. 



Lunulites (Cupularia) rutella, Spec. nov. 



PI. I., fig. 2a— 2d. 



Zoarium irregularly orbicular, thin, much depressed. Zoooscia 

 squamosely radiating, oval, somewhat depressed above, but 

 elongating below into a projecting overlapping somewhat 

 narrow rounded edge. Lamina immersed with two large 

 pyriform pores at each side below, and two or three small 

 rounded ones above. Margins thickened and raised. Avicular 

 pores numerous, much smaller than the cells, elongately 

 triangular, rounded at the apex, and a distinct raised margin. 

 The whole surface finely granular and shining. Under surface 

 with broad very irregular undulating uneven radiating some- 

 times bifurcating faintly granular ribs. 



Locality and Horizon. — Muddy Creek Miocene beds, near 

 Hamilton. Upper Murravian beds ; and lower Aldinga marls 

 (Prof. Tate). 



This is one of the most elegant of our fossil species- The 

 openings are so large and defined that without the assistance 

 of a lens they can be discovered. The avicular pores are some- 

 times in a line for a series of three or four, but they are 

 always interrupted and never in a regular line like Lunulites. 

 The cells are not quincuncially arranged, so that the generic 

 position of this species would be very doubtful. The under 

 surface is similar to Lunulites aperta, and quite different from 

 the iisual kind of ornament at this part of the zoarium among 

 Selenariadse. 



Genus Lunulites , Lamouroux. 



Cells arranged in more or less regular series radiating from 

 the centre. Vibracula in linear series, alternating more or 

 less regularly with those of the cells. 



This definition, which is that of Busk, shows how very 

 difficult it would be to draw a line between Lunulites and 

 Cupularia. It seems to me that if the cells are quincuncially 

 arranged the vibracular pores will not be in a line ; but if not 



