Zoology.] NATUEAL HISTORY OF VICTORIA. \Polyzoa. 



Plate 97, Fig. 7. 

 RETEPORA CARINATA (P. McGL). 



Description. — Polyzoary expanded 5 fenestra elongated, narrower than the 

 interspaces ; cells ovate, broad, separated by narrow raised margins ; mouth (primary) 

 with the lower lip entire, or (secondary) with a deep sinus at one side and a large 

 avicularium towards the base of the prominent peristome ; operculum rounded above, 

 hollowed below, broader than high ; on the inner margin of the fenestrse several 

 avicularia with long, pointed mandibles directed vertically from before backwards ; 

 ovicell subimmersed, pyriform, with a vertical, sharp ridge slightly bulbous at its 

 upper extremity; dorsal surface granular, traversed by slightly raised vibices, and 

 with a few rounded avicularia about the edges of the fenestrse. 



Reference.— P. H. MacGillivray, Tr. Roy. Soc. Vict., 1883. 



The only specimen I have seen of this very distinct species was 

 dredged at Port Phillip Heads. It is perfect, and forms a waved, 

 somewhat fan-shaped expansion, fths of an inch wide by about 

 Jths deep. The cells are mostly broad, prominent, tubercular, and 

 glistening. The mouth is broad, arched above, and in the youngest 

 seems to be entire and straight below or slightly convex. The 

 peristome is rapidly developed on the lower lip, projecting as a 

 plate with a deep notch at the angle of the mouth on one side, and 

 receding gradually from this to nearly the level of the opposite 

 angle, but without any notch on that side. The margin is frequently 

 finely serrated. There is a considerable prominent avicularium 

 below the lower lip, with the broad mandible directed upwards, 

 usually inclined to the angle formed by the sinus. There are also 

 other round or elliptical avicularia scattered in various parts, and 

 numerous avicularia with long narrow mandibles, closing in biden- 

 tate rostra, close to the edges of the fenestrse. Similar avicularia 

 occur in some other species ; but in these, so far as I have seen, 

 they always open horizontally inwards, while in the present they 

 are directed across the edge of the fenestrse. The vertical slit, the 

 closure of which gives rise to the vertical ridge on the ovicell, is 

 still in some instances slightly open towards the upper extremity. 



Explanation of Figures. 



Plate 97. —Fig. 7, specimen, natural size. Fig. la, portion magnified. Fig. lb, portion of 

 dorsal surface, half as much enlarged. 



Dec. x. [ 25 ] D 



