BY W. M. BALE. 781 



slender at the base and moveable ; one below each hydrotheca, 

 and one at each side above it, one between every two hydrothecae, 

 on the intermediate internode, one at the base of each pinna, and 

 one on the lower part of each stem-internode. 



Gonothecse small, ovate or oblong, somewhat compressed, slightly 

 narrowed at the summit. 



Hob. Bondi Bay, Port Jackson. 



This species differs from P. setacea in its smaller size, and in the 

 gonothecae, which are stouter in proportion, and have no neck. As 

 seen in side view they are nearly oblong, but in front view they 

 are somewhat barrel-shaped. Some of them are rather abruptly 

 narrowed towards the summit, but this is not always the case ; 

 possibly the difference is developmental. The hydrothecae are some- 

 what shallower in proportion to their height than those of P. setacea y 

 and more rounded. In one of the specimens the pinnae are borne 

 in opposite pairs at the summit of each internode, except at the 

 upper part, where the ordinary alternate arrangement recurs. 



PLUMULARIA SETACEOIDES, Bale. 



Bondi. < Plate XX " 7 - 8 )' 



This is a rather small form of P. setaceoides with short pinnae, 

 and, like the small southern variety, has the hydrothecae shallower 

 and more expanding towards the aperture than the long slender 

 form. They are also set at a wider angle on the pinna, and have 

 the front so much thickened as to present the appearance of an 

 outer chitinous investment at this part. The thickened portion 

 shrinks when the zoophyte is preserved in. balsam, and even to 

 some extent when in water. Gonangia are plentiful in these 

 specimens, and agree in their general form with those of the type. 

 The large sporosac is sometimes surrounded at the summit by a 

 circle of highly refractive granules, which, as they are not present 

 in all the gonothecae, would appear to belong only to a particular 

 stage of growth . 



