11 



pores ; between these ribs tbere are always fine raised lines, 

 which branch two or three times towards the margin. 



Diameter, four millimetres ; altitude, one millimetre. 



A peculiar and very neat form, very granular, and the 

 granules projecting on the edges of the zoarium, like 

 asperities. The avicular cells are edged with fine, sharp, 

 spiny-like teeth, which almost close the aperture of the cells. 

 This structure is quite unique in the genus. The zoooecia are 

 all depressed, and do not project in any way, or overlap one 

 another ; but the surface is pitted, and appears without a lens 

 somewhat like the top of a thimble. 



Locality and Horizon. — -Muddy Creek Miocene beds, near 

 Hamilton. 



Sele^aria alata, Spec. nov. 

 PI. II., fig. 12a— 12c. 



Zoarium rather large, orbicular, moderately convex, solid ; 

 edges thick, spongy. Zoooecia elongately semicircular, over- 

 lapping squamosely ; margins distinct, raised ; area depressed ; 

 aperture large, narrowed above by triangular alae at each side. 

 Avicular areas larger than zoooecia, very few in number, with a 

 large ear-shaped pore in the midst of the area. Under surface 

 very finely punctuate, with a few radiating fine grooves, forking 

 two or three times towards margin, between which there are 

 many large pores in a double or single line of irregular sizes 

 and intervals. 



Diameter, rather more than 6| millimetres ; altitude, ex- 

 ceeding 2-L 



The cells are a little more constricted than they are repre- 

 sented in the drawing, and this I believe to be the distinction 

 between this species and var. a, which I distinguish as var. 

 lata. 



Seleitaria alata, var. lata, nov. 



Zoarium small, orbicular, solid, moderately conical, the 

 younger specimens most so, base flat. Zoooecia rhomboidal ; 

 margins raised ; centre depressed with a very large oblong 

 square opening with the angles rounded ; the summit curved 

 and the sides slightly constricted by the projection of the 

 margin. Ear back in the opening there is a large semicircular 

 pore. The whole surface granular. Avicular pores very few 

 in number, something like the cells in shape but smaller. 

 Under surface with deep irregular grooves and pores of large 

 sizes forming a pattern very like rustic work in architecture. 



Diameter of zoarium, about four millimetres. 



The shape of the aperture in this variety is very like S. alata 



