Zoology.] NATURAL HISTORY OF VICTORIA. [Polyzoa. 



Plate 99, Fig. 9. 

 RETEPORA SERRATA (P. McG.). 



Description. — Polyzoary expanded; fenestrse about the same width as the 

 interspaces, or slightly wider; cells much elongated, separated by raised lines; 

 mouth nearly circular or oval, projecting forwards, with a small sinus below, and a 

 fringe of about 12 short, pointed processes arranged round the margin ; operculum 

 higher than wide, contracted at the base ; ovicell rounded, smooth ; a sessile avicu- 

 larium, with a long, narrow, pointed mandible at the bottom of each fenestra, 

 opening directly upwards ; dorsal surface obscurely tubercular, strongly vibicate. 



Reference. — P. H. MacGillivray, Tr. Roy. Soc. Vict., 1882. 



Port Phillip Heads, a single specimen. 



The only specimen I have seen is the very perfect one figured. 

 It forms a small expansion f ths of an inch in diameter, curved on 

 itself on one side where it is attached to the calcareous tube of an 

 annelid. The colour is leaden-grey. The cells are elongated, 

 narrow, slightly expanded upwards, separated by narrow raised lines. 

 In the youngest the mouth is smooth, the lower lip straight, slightly 

 hollowed or with a slight sinus. The peristome is rapidly developed 

 to form a serrated circle of small sharp teeth, projecting forwards ; 

 at the lower part of this circle is a small sinus. At the bottom of 

 each fenestra is a sessile avicularium, the rostrum with a tooth on 

 each side behind the strong curved apex, the mandible long, 

 narrow, curved, and pointed. There are a few other large avicu- 

 laria, situated on mound-like elevations on the cells, and with 

 spatulate or linguiform mandibles. The back is obscurely tuber- 

 cular, glistening, divided into numerous angular spaces by narrow, 

 sharply -raised vibices ; a few scattered, rounded avicularia are 

 situated about the edges of the fenestra. 



Explanation of Figures. 

 Plate 99. — Fig. 9, specimen, natural size. Fig. 9a, portion, magnified. 



I am indebted to my friend Mr. MacGillivray for this valuable 

 series of Reteporce, which he has contributed to the National 

 Museum collections and this work. 



Frederick McCoy. 



[31 ] 



