Plate 39. 



Fig. 1. Tuberella ciliata. Latero-superior surface. XJ. 



2. Tetilla ciliata. From the side. XI. 



3. Tetilla spinosa. From the side. Xi. 



4. Tetilla {Cinachyrella) clavigera ( Hentschel ) . X|. 



5. Tetilla {Cinachyrella) cntstata. Upper surface; apertures of porifer 



ous pits on this surface and at margin. X'i. 



6. Tetilla {Cinachyrella) paterifera. From the side; apertures of pits 



more or less contracted and therefore with sharp margin. Xf. 



7. Tetilla {Cinachyrella) crustata, var. patellae-spinosae. Obliquely from 



the side, showing a spinous (oscular) area and a number of 

 poriferous pits. XJ. 



8. Tetilla {Cinachyrella) paterifera. From the side; poriferous pits 



wide open. XJ. 



509 



