or Little Knoivn, Polyzoa. 119 



Membranipora Rosselii, Fig. 4. 



I am not quite satisfied that the M . Rosselii of The Decades 

 is identical with the European form. The cells are arranged 

 much more regularly than in the only English specimen I 

 have seen, and they are more rhomboidal in shape, although 

 agreeing so far with Hincks' figure. In many cases the upper 

 margin of the aperture is not straight, but is extended slightly 

 forwards in the middle or towards one side, to form a broad 

 sinuous projection, occupying about two-thirds of the width. 

 The avicularium is very large, replacing a cell, with a long- 

 rounded mandible, directed upwards and forwards, and occu- 

 pying the whole width of the cell ; the upper edge of the 

 avicularium is calcareous and projects considerably forwards. 

 In some cells there is a little additional thickening, filling in 

 the lower angles of the area, and there is occasionally here a 

 small rounded process, on one or both sides, close to the 

 margin of the cell below. 



Membranipora patellaria, Moll sp. Fig. 13. 



Mollia pcctellaria, Smitt, Floridan Byozoa, Pt. II., p. 12. 

 Fig. 72. 



Diachoris patellaria, Waters' Ann. and Mag. Nat. Hist., 

 Feb., 1879. 



Cells slightly separated and connected by short tubes,, 

 oval and lozenge-shaped ; margins raised, crenulated ; lower 

 two-thirds filled in by a minutely granular calcareous mem- 

 brane ; aperture nearly semi-circular, occasionally somewhat 

 trifoliate. 



Port Phillip Heads. 



Of this I have dredged a single specimen, growing on a 

 small sandy and calcareous nodule. It agrees perfectly with 

 the form described by Waters, from the Bay of Naples, as 

 Diachoris patellaria, var. multijuncta. The cells are only 

 slightly separated, and, in parts of the specimen, are so close 

 together that the connecting tubes are scarcely distinguishable. 

 Each cell is connected with the adjacent ones by usually 

 about twelve tubes. In my specimen there are a few imper- 

 fectly developed ovicells on the summits of some of the 

 cells at the growing margin ; they are rounded, smooth, 

 and closely adherent to the cells above. In the typical 

 form, as figured by Smitt and Waters, the connecting tubes 

 are much fewer. These naturalists consider Heller's D. 

 simplex as the same species which they refer to Moll's 



