368 APPENDIX. 



remarkable elevation of tlie sharp margin surrounding tlie 

 upper half of the cell. In the looser aggregation^ and in 

 the form of the cells^ it shews the transition from Salicor- 

 naria to Cellularia. 



Fam. 2. CELLULARIAD^. Cells disposed in the 



same plane. 



10. Cellularia^ Pallas. 



Char. (B.) Cells bi-triserial^ oblong* or rhomboidal^ 

 contiguous. Opening of cell occupying at least half of the 

 fi'ont. Margin thickened, sometimes spinous above. A 

 short spine or a sessile a\icularium on the upper and outer 

 angle. 



A. inarmato: — without a^dcularium. 



1. C. monotrypa. n. sp. 



Cells oblong, narrowed below, with a single perforation, 

 in the upper and outer part behind. Opening oval, mar- 

 gin smooth ; a short spinous process at the upper and outer 

 angle; a sharp short spine in the middle of the upper 

 border of the middle cell, at a bifurcation. Ovicell? in 

 form of a very shallow excavation in the upper part of the 

 cell in front. 



Hab. — Bass Strait, 45 fathoms. 



The only species with which this can be confounded, is 

 C. Peachii, (Busk. Annals. Nat. Hist. Vol. 7- 2nd Series, 

 p. 82. PL A^III. fig. 1.) 



The latter, however, is very much smaller, the cells nar- 

 rower in proportion to their length, and the margin of the 

 opening minutely verrucose. The cell has more than one 

 posterior perforation ; and the central cell at a bifurcation 

 is rounded above and without a spinous process ; lastly, the 

 ovicell is much loftier and tesselated on the surface. 



* This shape of the cells is given from the back view of them. 



