430 REVISION OF THE MONAXONID SPONGES, iii., 



as identical, for in his paper(28) published but a year later than 

 the Catalogue, in which a complete classification of the sponges 

 is proposed, only one of these genera, viz., Spirophorella, receives 

 mention. Hence one would have thought that, as a precaution, in 

 view of the possibility of its becoming necessary later to unite the 

 genera, the author would have avoided using similar specific names 

 in the two cases; yet we find that the first-described of the two 

 species of Spirophora and the single species of Spirophorella are 

 both designated digital a, a name which moreover, is altogether 

 inappropriate as applied to the latter, since the species is, accord- 

 ing to description, "irregular, massive." The explanation of these 

 anomalies, I think, must in some way be connected with the fact 

 that the manuscripts of the Catalogue and of the paper on the 

 Chalininae were in course of preparation at one and the same time. 

 It is possible that Lendenfeld, having at first intended to refer the 

 the genus Spirophora to the GelliinaB, and having described two 

 species of it for inclusion in his paper on the ChalininaB, after- 

 wards decided to refer the genus to the Axinellidre, and to intro- 

 duce it in the Catalogue, but through an oversight omitted to delete 

 the paragraphs relating thereto from the manuscript of the former 

 paper; hence, that Spirophorella is merely another spelling for 

 Spirophora — preferred perhaps on account of the similarity be- 

 tween the names Spirophora and Spiriphora; and that Spiro- 

 phorella digitata is nothing more than Spirophora digitata 

 wrongly described in respect of its external characters. Support 

 to this suggested explanation is provided by the fact that, in the 

 key-list of Lendenf eld's manuscript names, Spirophora digitata 

 is written as the MS. synonym of Spirophorella digitata. 



Several specimens labelled Spirophora digitata, in Lendenfeld's 

 handwriting, occur in the Australian Museum, and these I regard 

 as correctly representing that species, which must now be called 

 Trachycladus digitatus. Contrary to Lendenfeld's description, 

 however, the megascleres are not styli, but almost exclusively oxea, 

 and the microscleres are of two kinds, spirulce and microstrongyles. 

 A description of this, and of some other species of Trachycladus, 

 will be given in my next paper. 



