Descriptions of New, or Little Known, Polyzoa. 131 



margin ; a transverse avicularium, with an acute mandible, 

 between the lower lip and the reniform pore ; ovicell large, 

 prominent, the front with a semicircular area, smooth, or 

 marked with radiating lines, the circumference being 

 thickened, and nearly smooth or granular. 



Port Phillip Heads. 



This beautiful species is at once distinguished by the 

 large, reniform, perforated plate and the transverse avicu- 

 larium. The avicularium is absent in some of the cells, but 

 seems to be present in all those supporting ovicells. The 

 reniform plate is distinctly raised, and has the appearance 

 of a thin membrane bulging forwards and pierced by 

 numerous punctures. In old, calcified specimens, the surface 

 is markedly areolated. 



Microporella stellata, Smitt.* Fig. 4. 



Cells broadly oval or rhomboidal, slightly convex ; surface 

 thickly covered with rounded eminences, each of which is 

 pierced by a stellate pore ; mouth wide, shallow, slightly 

 arched above and slightly projecting forwards below, margin 

 thickened ; at the summit of the cell and at each lower 

 angle of the mouth is a rounded eminence, on which is 

 situated an avicularium with the triangular mandible 

 directed towards the mouth, the superior vertically down- 

 wards, the lateral obliquely upwards and inwards. 



Port Phillip Heads, a single specimen, Mr. J. B. Wilson. 



Microporella Malusii, var. per sonata. Fig. 8. 



Cells pyriform, smooth ; mouth arched above straight 

 below, with slightly thickened edges ; no spines ; a trans- 

 verse, lunate, dentate pore below the mouth with the sides 

 elevated, especially inferiorly, into a mound-like prominence; 

 ovicell large, granular, the lower angles produced across the 

 front of the cell to form a large collar. 



Port Phillip Heads, a single specimen, Mr. J. B. Wilson. 



This differs so much from the normal form of M. Malusii, 

 that it mav be doubtful whether it ought not to be 

 characterised as a new species. There are no lateral pores, 

 the margin of the ovicell is not sculptured in the usual way, 

 and the lower angles are produced across the front of the 



* Porina stellata, Floridan Bryozoa, Part II., p. 26, PI. V. Figs. 130—133. 



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