490 THE AUSTRALIAN HYDROMEDUS.E, 



consider it as identical with it at first. I have however, since then 

 had occasion to study an Aglaophenia which possesses all the 

 characters of Bale's Aglaophenia parvula, and it also appears quite 

 impossible that so excellent an observer as Bale could have over 

 looked the generic difference between our Pentandra and his 

 Aglaophenia parvula. Pentandra parvula attains a height of 

 from 2-3 cm. 



175. PENTANDRA BALEI. 



Plate XIV., fig. 18, plate XVI., figs. 26, 27. 



Stem recurved, smooth, dark brown, Pinnae alternate simple, 

 one to each internode. Internodes very long. Hydrothecse cup- 

 shaped, margin dentate, teeth rounded, particularly large in the 

 inferior part, anterior part of the margin free, slightly elevated not 

 adnate. The inferior Nematophores pretty large barrel-shaped, 

 the superior paired and large Nematophores about twice the 

 length of the Hydrotheca with a lateral and terminal opening 

 slightly incurved, centrifugally, and of the same thickness through- 

 out. The medial superior Nematophore free in its upper end about 

 as long as the Hydrotheca with a single terminal opening, looking 

 obliquely forward. Corbula similar to that of the previous species. 



This Pentandra was dredged by the Hon. W. Macleay in Torres 

 Straits (Macleay Museum.) It attains a height from 3-7 cm. 



8. FAMILY DICORYNTBvE. 



Generative Zooids free swimming Polypes with two tentacles 

 and without a mouth, carrying two ova each. 



These Zooids bud only on Polypostyles, and never on the 

 alimentary Zooids which have one verticil of filiform tentacles. 



32. GENUS. DICORYNE. Allman, 1872. 



Hydrocaulus consisting of branched or simple stems, which arise 

 at intervals from a creeping filiform Hydrorhiza. Alimentary 

 Zooids fusiform, with a single verticil of filiform tentacles, sur- 

 rounding the base of a conical Hypostom. 



