with Observations on Australian Hydroids. 91 



Halicornaria simply in the absence of the lateral sarcotliec^. 

 The species on which it is founded, H. avicularis, had been 

 previously described by Kirchenpauer under the same specific 

 name, but, as he could not hnd the lateral sarcothecse, he 

 described them as minute. The Azygoplon rostratum of 

 the " Challenger" Report is the same species. 



DiPLOCHEiLUS, Allman. 



Hydrocladia pinnately arranged ; hydrothecae provided 

 with an outer calycine envelope ; mesial sarcotheca not 

 adnate to the hydrotheca, laterals absent. 



Gonosome unknown. 



This genus is distinguished by the duplicature of the 

 hydrotheca- walls. D. onirahilis, the only species, has the 

 mesial sarcotheca in the form of a concave disc, with a per- 

 foration in the centre. Its affinities are with the Eleuthero- 

 plea quite as much as with the Statoplea. 



Streptocatjlus, Allman. 



Hydrocladia uniserial, spirally disposed round the stem ; 

 trophosome otherwise as in Aglaophenia. 



Gonosome unknown. 



This genus is distinguished from all other Statopleans by 

 the spiral and uniserial disposition of the hydrocladia, and. 

 is the only genus yet known in the sub-family which has 

 the hydrocladia disposed otherwise than pinnately. 



III. — General Notes on Australian Hydroids. 



Campanularia rufa, Bale. 



This species resembles Lafoea halecioides, described by 

 Allman in the Report of the " Porcupine" expedition, but 

 may be distinguished by the stem-processes from which 

 spring the hydrothec^e, and which are much thicker than 

 the pedicles of the latter species. There is also a distinct, 

 though narrow, floor to the hydrotheca. 



Lineolaria flexuosa, Bale. 



The gonangia of this species, hitherto unknown, may be 

 defined as follows : — 



