Zoology.-] . NATURAL HISTORY OF VICTORIA. \_Polyzoa. 



Form munita (Hincks). 



Plate 96, Figs. 4-8. 



Description. — Polyzoary expanded, foliaceous, convoluted to form large 

 cavernous or calyculate masses ; cells separated by narrow raised lines, surface 

 granular ; peristome expanded forwards, with a loop-shaped mark in the centre of 

 the lower lip, closed or perforated below, on one side of which is an avicularium. 

 Small oval avicularia on the front of the cells, and various others scattered in different 

 parts. A very large avicularium, with either a semilunar or a very long, triangular, 

 pointed mandible, above the upper angle of each fenestra ; ovicells with the beaded 

 line narrow; posterior surface granular; vibices well marked; elliptical avicularia 

 more abundant about the edges of the fenestra. 



The largest specimen I have measures 2J by 3 inches ; but as 

 all my others are incomplete, it probably attains a considerably 

 greater size. The convolutions of the polyzoary form large cavities, 

 and are not closely plicated as in the form monilifera. The peri- 

 stome is usually much elevated forwards, with a loop-shaped mark, 

 or occasionally a fissure, on one angle of which is a small avicu- 

 larium. This avicularium is frequently, however, absent. It is 

 also sometimes very much elevated on a production of the peri- 

 stome. There is occasionally a thin spine at each side of the mouth 

 above, but I have never seen the large jointed spines found in the 

 other forms. 



Two varieties are distinguishable. In the one, lunata, the 

 supra-fenestral avicularium has the mandible semilunar and very 

 large, and the loop of the peristome is usually imperforate. In the 

 other, acutirostris, which is also usually altogether stouter, the 

 same avicularium has an enormous, pointed mandible ; and the 

 peristome is occasionally perforated. Occasionally both forms of 

 large avicularia occur on the same specimen. 



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