the Genus Tragosia, Gray. 171 



ho has made use o£ the name Trayosia on several occasions, 

 has not, so far as I am aware, done anything to extend our 

 knowledcje in this direction. We may safely say tliat 

 hitherto the genus Trayns'ia has remained very badly charac- 

 terized, and one can hardly be surprised that Carter [187G] 

 completely ignored it and referred Bowerbank's Isodiclija 

 infiditiibalifonnis to Fhakellia ; indeed, he seems to have 

 actually confused the species with PhakeUia ventiluhrum. 



We come now to the chief object of this note, which is to 

 call attention to a hitherto-unnoticed, element in the spicu- 

 lation of Trayosia iiifniK/ibu/iformis, by the aid of which the 

 confusion between Trayosia and PhakeUia can at once be 

 avoided and the genus [)laced upon a more satisfactory 

 footing. 



Some years ago I received from Sir W. A. Ilerdman three 

 beautiful specimens of Trayosia infundibitliformis collected 

 in the Minch and preserved in alcohol. The external form 

 of these speciiuens is thoroughly typical and, taken in con- 

 junction with the locality, left little doubt as to the idcnti- 

 Hcation. In order to make quite sure, however, I recently 

 examined the spieulation of one of the specimens, and was 

 much surprised to find numerous microscleres in the form 

 of trichodragmata. 



Before coming to the conclusion that trichodragmata 

 really form a normal constituent of the spieulation, it was 

 necessary to make a re-examination of specimens actually 

 referred to the species in question by the older writers. In 

 the first place, I found in Mr. Carter's cabinet a slide 

 labelled '■'' Halichondria infundibuliformis. Johnst. B. AI. 

 Shetland ", which is evidently a preparation x>i Trayosia 

 infundibuliformis, and which contains trichodragmata quite 

 unmistakably. Unfortunately the same slide is also labelled, 

 at the other end, " Type s])eciinen PhakeUia robusta, Bk." 

 Two other slides, both labelled " PhakeUia infundihularis " 

 and " Deep Sea," are evidently from the ' Porcupine ' 

 collection, but they represent two distinct species. The 

 one has trichodragmata and may be safely identified as 

 Trayosia iifundibuliformis] the other has no trichodragmata 

 (so far as I can see) and much larger megascleres, and is 

 })robably referable to PhakeUia ventilabrum. It is evident 

 from what Mr. Carter says a!)out these species in his paper 

 on the ' Porcupine ' Sponges [1876, pp. 239, 240], taken in 

 conjunction with his preparations, that he failed to dis- 

 tinguish the one from the other. 



There are in the Natural History Department of the 

 British Museum a number of dry specimens undoubtedly 



