258 Proce-'diiigs of the Royal Irish Acadein//. 



The followiug species are described : — (S. inoiiilli/ormc nov., S. profunda 

 nov., S. gracilis nov., S. rubra uov. 



Hickson (xv, p. 819), in discussing this group, says that the four genera 

 Juncella, EUisella, Scii'pearia, and Scirpearella are undoubtedly related. He 

 takes exception, however, to the distinction between Juncella and EUisella 

 based on spicular characters, and proposes to unite them under the name 

 Juncella. At the same time he refers the genera to two groups — 



(1) those with club-shaped spicules, and 



(2) those without club-shaped spicules. 



On this system he gives the following arrangement of the species: — 

 With clubs :— 



J. juncca Pallas. 



J. f/cinmacM (Milne-Edwards). 



J. flcxilis (Studer). 



J. fragilis (Ridley). 



J. hctrhadcnsis (Wright and Studer). 

 Without clubs : — 



J. elongate (Valenciennes). 



J. calamus (Studer). 



J. maculata (Studer). 



J, spiralis Hickson. 



He also makes the following note : — " J. hcpnlim (Klz.) may not be 

 distinct; and J.funienUna (M. and D.) and J. lacms Verrill are not sullicieutly 

 well known to be classified in this system." 



The genera Scirpearia and Scirpearella he, however, retains as being 

 capable of identification as follows : — 



Scirpearia — prominent verrucae in two rows. 



Scii-pearella — prominent verrucae arranged in a spiral manner. 



Before considering to what e.xtent any or all of these systems of classifi- 

 cation may be regarded as an aid to the detennination of natural affinities, it 

 will be well to renew all the characters, macroscopic and microscopic, upon 

 which stress has been laid, and also any others which might serve to elucidate 

 the relationships existing in this group. 



