90 A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 



Adeonella, Busk. 



1. A. triton, n.sp. PL IX., fig. 23. 



Zooecia large, niuch elongated, distinct ; surface smooth, with a row of large 

 pores round the margin and extending above the thyrostome ; thyrostome very 

 lofty, arched above, narrowed downwards and hollowed below ; an avicularium with 

 long narrow mandible on one or both sides below the thyrostome, directed upwards 

 and reaching to about the middle of its side. Ocecial cells very large ; sides 

 bordered by a row of very large pores ; a slightly elevated area about the middle of 

 the cell, with five or six pits or pores ; aperture very wide, peristome very thin and 

 raised, upper lip arched, lower projecting upwards ; a narrow raised ridge or keel 

 extending vertically from the middle of the lower lip to the perforated area ; an 

 avicularium on either side below the thyrostome directed slightly inwards and 

 reaching nearly to the lower lip. 



M.O. 



The systematic position of this very peculiar species admits of great doubt. Its 

 whole aspect closely resembles Adeonellopsis, with which it agrees in the structure 

 and situation of the avicularia and of the large ocecial cells. The ordinary zooecia, 

 however, have no zooecial pore or cluster of pores, and the cluster of pores or pits 

 on the ooecial cell is raised and the pores themselves not stellate. The shape of the 

 thyrostome also is different. On the whole, I think it ought to be referred to the 

 Escharidse, from the other genera of which it is differentiated by the ocecia being 

 internal in modified cells, in the same way as Adeona and Adeonellopsis differ from 

 the other Microporellidse. I have only seen the one specimen. 



Family Smittiid^. 



Zoarium crustaceous, or erect and uni- or bilaminate or dendroid. Zooecia 

 entirely calcareous, without membranous lamina or special pores ; thyrostome 

 variously shaped, entire (Rhynchopora) with a sinus below ; a special development 

 of the peristome forming the secondary orifice. Ooecia external. 



Porella, Gray. 



Zooecia with the thyrostome subcircular ; secondary orifice horseshoe-shaped or 

 inversely triangular, with an avicularium within or on the edge of the peristome 

 below. 



1. P. concinna, Busk, sp. PL XII., figs. 6, 7. 



Lepralia concinna, Busk, B.M.C., II., p. 67 ; Porella concinna, Hincks, 

 B.M.P., 323. 



