396 APPENDIX. 



the rachis by a broad ventricose base, adnate the whole 

 length of the cell, narrow upwards and sUghtly expanded 

 again at the summit; lateral processes very short and 

 wide, canahcular adaate. Costse of ovarian receptacle 

 numerous, each with a single branch near the bottom, 

 and beset with small cup-Hke processes, and not connected 

 by a membrane. 



Hab. — Port Curtis. Off Cumberland Islands, in 27 

 fathoms fine grey mud. 



Colour yellowish white. Polypidom about 6 inches 

 high, rising with a siagle flexuose .stem, which is naked at 

 bottom, and afterwards gives off alternate branches, bifa- 

 riously disposed at each angular fluxure. Branches simple, 

 2 — 3 iQches long ; pinnules about i inch. The construction 

 of the ovarian receptacle in the present section of the 

 genus Plumularia is well exemphfied in this species, owing 

 to the comparative simplicity of the elements of which it 

 is composed. 



2. P. Mans, n. sp. 



Cell cup-shaped, deep, cylindrical ; mouth nearly vertical; 

 margin with three teeth on each side, the middle one the 

 longest, acute, much expanded, the other more rounded ; 

 a wide notch posteriorly. Rostrum, arising from the 

 rachis, as long as the cell, slender, tubular, adnate ; lateral 

 processes very small, ovarian receptacles — ? 



Hab. — Prince of Wales Channel, Torres Strait, in 9 

 fathoms. 



Colour bright brown, rachis shining, very dark brown ; 

 polypidom about six inches high, simply pinnulate, pin- 

 nules about half an inch ; thickly and regularly disposed, 

 alternate. 



3. P delicatula, n. sp. 



Cell cup-shaped, rounded, mouth at an angle of 45o; 

 margin dentate, with two lateral teeth of equal size and a 

 central one in front longer, all acute ; entire posteriorly. 



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