APPENDIX. 397 



Rostrum a little longer than the cell, scarcely connected 

 with the rachisj slender, and closely adpressed and adnate 

 to the cell below, wide and projecting upwards ; lateral 

 processes large, rising above the margin of the cell, coni- 

 cal, tubular, or canahcular. 



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

 fathoms. 



Colour of rachis and pinnules, deUcate yellowish white 

 above; of rachis, light brown, inferiorly; polypidom 

 about two inches high, rising in several straight simply 

 pimiulated fronds from a common centre ; pinnules ascend- 

 ing about } inch. 



4. P. aurita, n. sp. 



1 Cells cup-shaped, tapering at bottom, constricted just 

 below the top ; mouth at an angle of 45°, circular ; margin 

 subcrenate, plicate, with three folds on each side, with a 

 wide shallow notch in front and entire behind. Rostrum, 

 slender, attenuated below, adnate up to the cell, summit 

 contracted, tubular; lateral processes very long, expanding, 

 rising far above the margin of the cell, conical, tubular. 



Hab. — Off Cumberland Isles, 27 fathoms. 



Colour bright brown ; polypidom 2 — 3 inches high, con- 

 sisting of straight pinnate fronds, pinnae or branches not 

 opposite, nor regularly alternate, divaricate at right-angles. 



5. P. hrevirostris, n. sp. 



Cell sub-tubular, curved; mouth expanded with two 

 equal acute teeth on each side, and a longer narrow 

 and sUghtly incurved, central one in front. Rostrum 

 small, conical, projecting, about half the length of the cell ; 

 lateral processes small, recurved at an angle, canaUcidar. 



Hab. — Off Cumberland Isles, 27 fathoms. 



Colour dirty white. In habit, and to the naked eye, very 

 much like the last; its growth, however, appears to be 

 longer and less regular. The difference in the cell is 

 very great. 



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