350 



REVISION OF THE MONAXONID SPONGES, 11., 



ill addition to the single type-specimen, which is labelled 

 "Trimcatella diyitata" and conforms closely to Lendenfeld's 

 description, these also include the specimens labelled as the 

 types of Stylotella rigida, Tedania laxa, and T. tenuispina — 

 which three species, for reasons more clearly indicated in due 

 course, I propose to regard as synonyms of S. agminata. Two 

 further examples of the species occur also among the frag- 

 /-v ments of sponges received from the British 

 Museum, one labelled ''Truncatella 7?iicro- 

 pora" (a MS. name), the other mistakenly 

 labelled as "Glathriodendroji irregularis." 

 Among these fragments there is also one 

 labelled ''Stylotella digitata, Port Nelson, 

 N.Z.," but this proves to belong to quite a 

 different species ; as a consequence there is 

 reason to doubt Lendenf eld's correctness in 

 recording the species from any locality other 

 than Port Jackson. 



Description.- — The external features of the 

 species have already been sufficiently de- 

 scribed by Ridley and by Lendenfeld : in 

 regard thereto, the latter author's descrip- 

 tions of Stylotella digitata and Tedania laxa 

 are applicable, but not strictly his descrip- 

 tions of S. rigida and T. tenuispina. The 

 oscula, concerning which these several de- 

 scriptions are not quite in agreement, ap- 

 pear always to be few in number, scattered, 

 and small ; and usually to be more or less 

 closed over by extensions of the dermal 

 membrane. Ridley(33) has given a figure 

 which conveys a very good idea of the form commonly assumed 

 by erect specimens with cylindrical branches, and to this, I 

 now add several others — one of which (Pl.xix., fig. 3) shows 

 an erect form, with crowded compressed parts due to imper- 

 fectly differentiated branches; while another (Pl.xix., fig. 4) 



Fig. 6. 



Stylotella agminata. 

 a, Styli (or subty- 

 loatyli). a', Basal 

 extremities of sub- 

 tylostyli. 



