288 Description of New, % 



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. The ovicell is rounded, projecting, smooth, and 

 destitute of a fissure. 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 avicularia", 

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

 spatulate, or linguiform mandibles. The back is obscurely 

 tubercular, glistening, divided into numerous angular spaces 

 by narrow, sharply-raised ridges ; a few scattered, rounded 

 avicularia about the edges of the fenestras. 



Retepora aurantiaca, n. sp. Fig. 5. 



Polyzoary expanded, foliaceous, convoluted. Fenestra? 

 elliptical, or oval, about the same width as the interspaces. 

 Cells quadrate, separated by narrow raised margins ; mouth 

 rounded above, straight below, with a deep narrow sinus, on 

 one side of which is a rounded avicularium ; a long, jointed 

 spine articulated on each side of the mouth; usually a round, 

 vertical, or oblique avicularium on the front of the cell. 

 Ovicell large, pyriform, with a vertical narrow fissure, wider 

 above, and with thickened margins. Back strongly vibicate, 

 granular, and with numerous, small, rounded avicularia, 

 similar to the anterior ones, especially abundant near the 

 fenestras. 



Dredged off Port Phillip Heads. 



The largest complete specimen I have found forms a 

 foliaceous, convoluted polyzoary, three inches wide by about 

 two in the other diameters. The base of attachment is 

 about an inch long. Some fragments indicate that it attains 

 a still larger size. The avicularium on the front of the cell 

 is by no means constant. The ovicells are abundant, and 

 have a very distinctive appearance. It is of a beautiful 

 orange colour. 



Retepora avicwlaris, n. sp. Fig. 6. 



Polyzoary expanded, curled. Fenestras elongated, wider 

 than the interspaces. Cells elongated, separated by distinct 

 margins ; mouth arched above ; lower lip with a small 

 suboral avicularium at the centre (frequently absent, and 

 leaving a loop-shaped notch), on each side of which is a 



