80 The Genera of the Plwmulariidce, 



Gonangia unknown. 



H. carinata, the only species, agrees with the typical 

 Eleutheroplea in the form and position of the calycles, and 

 the anterior sarcothec^, though fixed, are attached by a 

 slender base. The supracalycine sarcothecse are described as 

 adnate to the side of the hydrotheca, which character is 

 unknown elsewhere in the sub-family. In Professor 

 Allman's figures, however, the cup of the sarcotheca is shown 

 raised above the margin of the hydrotheca, and the long- 

 tubular adnate portion seems rather to resemble the peduncles 

 which, in several species of Plumularia, support the sar- 

 cotheca, than an intimate part of the latter organs. 



ACANTHELLA, Allman. 



Hydrocladia pinnately arranged, those near the tips of 

 the branches replaced by spines; sarcothecce not attached to 

 the hydrotheca. 

 " Gonosome unknown. 



The genus Acanthella is formed for the single species, 

 Plumularia effusa (Busk), and differs from Plumularia only 

 in having spines armed with nematophores in place of the 

 hydrothecal ramules towards the extremities of the- 

 branches. 



Antennella, Allman. 



Hydrocladia simple, springing directly trom the hydro- 

 rhiza; sarcothecce not attached to the calycle. 



Gonangia not provided with phylactocarps. 



This genus is distinguished from Plumularia by the 

 absence of a stem. In several Plumularians, however, simple 

 ramuli like those of Antennella have been found OTowino- 

 from the same hydrorhiza with ordinary pinnate shoots. 

 This has been observed by Busk in Plumularia campccnula^ 

 by Kirchenpauer in P. Jilicaulis, and by myself in Halicor- 

 naria hw^nilis, and it is quite possible that all the species of 

 Antennella may be similar stemless forms of ordinary 

 ramulose species. 



ScHizoTEiCHA, Allman. 



Hydrocladia pinnately arranged, bifurcating once or 

 more; sarcothecce not attached to the hydrotheca. 

 Gonangia not provided with phylactocarps. 



