746 SOME NEW AND RARE HYDROIDA IN THE AUSTRALIAN MUSEUM, 



SERTULARIA FERTILIS, von Lendenfeld. 



I.e. p. 406, PL VII., figs. 4-5. 



This supposed species is founded on specimens of a Thuiaria 

 (T. sub-articulata, Cough trey), from which the brittle hydrothecse 

 have been broken away. The portions figured as hydrothecae are 

 not really such, but only the projecting portions of the hydro- 

 caulus on which they have been supported, and the apparent 

 teeth on the outer margins are merely remnants of the front of 

 the hydrotheca, which are frequently left adhering when the rest 

 of the cell is lost. I figure on Plate XVIII., fig. 8, a fragment 

 of one of Dr. von Lendenfeld's type specimens, in which one 

 of the hydrothecse is preserved. I have another specimen from 

 New Zealand, differing from Dr. von Lendenfeld's in the much 

 lighter colour, and in this also most of the hydrothecse are lost or 

 injured. 



Professor Allman describes T. sub-articulata (under the name of 

 T. bidens) as having two teeth on the inner side of the hydrotheca 

 and the rest of the margin smooth, while Mr. Coughtrey says 

 that there are two teeth on the outer side, in addition to the inner 

 two. The outer teeth are present in all the cells which I have 

 seen, but it is often difficult to distinguish more than one tooth on 

 the inner side. 



PLUMULARIA GRACILIS, von Lendenfeld. 

 l.e. p. 476, PL XIV., fig. 17 ; PL XVII., figs. 28-29. 



The type is a specimen of P. Ramsayi, Bale. Neither the 

 detailed figure nor the description agrees with the specimen, which 

 does not possess a mesial sarcotheca above the hydrotheca on the 

 same internode, as represented. 



PLUMULARIA RUBRA, von Lendenfeld. 

 l.c. p. 476, PL XIII., figs. 11-12; PL XIV, fig. 15. (See page 778). 



