28"2 Proceedings of the Royal Irish Academy. 



5. JuneeJla gemmacM^ Valenciennes. 



6. JunceUa ractmosa "Wright and Studer. 



7. JunteUa miniaeea Thomson and Henderson. 



8. Juncdla trilineata Thomson and Henderson. 



But in addition to these the following species have been also referred 

 to this genus : — 



9. JunceUa santat-erueis Duch. and MIcIl 



10. Juntella funieulina Duch. and Mich. 



11. JiiHuUa harbadensis^ Duch. and Mich. 



12. Juncdla rimcn Ellis and Solander. 



13. Juncdla calyculata Ellis and Solander. 

 14 JunceUa hydrix Valenciennes. 



15. Juncdla suradus Johnson. 



16. Juncdla lacris Verrill. 



17. Juncdla extans VerrilL 



Species 9-17 are, however, so imperfectly known that it is absolutely 

 impossible to include them in any scheme of classification. In several cases 

 they are names without descriptions ; and in the others, the descriptions are 

 extremely vague, and are based on characters which are now known to be of 

 no specific value. In no case have the spicules been investigated, so that it is 

 even impossible to say whether they actually belong to this genus or not ; 

 in fact, it b more than probable that they are not all referable to Juncdla. 



I have carefully searched through several old collections for authentic 

 specimens of any of these ; but the result has been negative, so that in the 

 absence of type-specimens, but for the sake of completeness, it has been 

 decided to place them in a group — " incertae sedis " — by themselves, and give 

 such references and descriptions as are available. 



An attempt, however, has been made to trace the affinities of species 1-8 

 Each of these is discussed in detail under its place in the emended classi- 

 fication suggested later, so that it is necessary here only to consider the 

 characters on which the classification is founded. 



The first and most important of these is " the number of viain longitudinal 

 canals," and this at once separates off Juncdla trilineaia from the others. 



An examination of the spicules marks Juncdla raccmosa as distinct (see 

 figs. 14 and 23j. In addition to this, however, the general nature of the 

 colony and the mode of branching are distinctive for this species, which 

 under the present system includes Juncdla minncea. There, therefore, remain 

 only species 1-5 to be considered. JunceUa JUriiii, J. fragilis, and J. barba- 



