270 R. HARTMEYER. 



are not given however, but it seems possible to decide with certainty 

 from the external characters alone that it refers to our species. 

 Aplidium Jicoides is probably only a synonym. I have recently had in 

 my hands many colonies which were also collected off the Belgian 

 coast, so tluit the occurrence of the species there is certain. 



Ansted and Latham also record Aplidium Jicus in a list of the 

 Ascidians of the Channel Islands. This statement cannot be tested. 

 I have myself not seen any example of this species from the Channel 

 Islands, although I have identified a great deal of ascidian material 

 from that locality. It appears however by no means improbable that 

 the species occurs there, probably in deeper water. I come to that 

 conclusion because Giard (1873) also mentions a Polyclinum ficus 

 from the neighbouring coast of Granville, which he identifies as 

 Ellis' species. I do not doubt that this P. ficus of Giard is the same 

 as our species. Giard thinks it probable that the species lives in deep 

 water and is only occasionally thrown on the shore. That would also 

 explain the fact that the species is mentioned neither by Milne- 

 Edwards nor by Lahille, and consequently we may conclude that it 

 does not occur within the limits of the true littoral zone on the north 

 coast of France. 



Pelseneer (1892) mentions the species from Blankenberghe> 

 where it is frequently taken by the fishermen; Bizet (1892) from the 

 coast of Somme. It seems to me however questionable whether in 

 the latter case our species is really concerned, possibly there is a con- 

 fusion with Glossoforum sabulosum. Sharp (1911) mentions the species 

 again from the Channel Islands (Cobo). The same remarks apply to 

 this record as to that of Ansted and Latham. Finally in the 

 posthumous work of Alder and Hancock (1912) published by 

 Hopkinson a numerous collection of references to this species is to 

 be found, in which however references which belong to the sponge are 

 erroneously included. In other respects this work furnishes nothing 

 new. 



An Aplidium or Polyclinum ficus is also repeatedly recorded from 

 the Mediterranean. Thus by Martens (1824), Grube (1864), Faber 

 (1883), and Cams (1890); Targioni-Tozzetti (1880) mentions an 

 Aplidium suhlohatum. In all these cases there is a mistaken identifica- 

 tion, since our species does not occur in the Mediterranean. Probably 

 in most eases the form dealt with is Amaroucium j^J/ramidale (Brug.) 

 (Syn. A. conicum (Olivi)). 



It is interesting to follow how in the course of years the specific 

 wQXiiQ ficus disappears more and more from the literature. Up to the 

 middle of the last century one misses it in hardly a single general 



