Stkpiiuns — The Fresh-ivahr Sponges of Ireland. 235 



on n. XXVI, fig. 9, d, e, were produced to the exclusion of other types, 

 the resulting sponge would possess spicules somewhat similar to those of 

 the sponges from Lough Erne, Lough Derg, and Louyli Gill (I'l. XXVI, 

 %s. 4, 6, and 8). With these may be compared the niicrospined spicule taken 

 from a perfectly typical specimen of E. Jiiirifdilis (I'l. XXVII, fig. 5). Jt 

 may be noted that these peculiar sponges have up to the present only been 

 found in the west and south, where the typical E. fluviatilis appears to be 

 rare. They occurred in abundance in the localities in which they were found. 

 No trace of such a form was discovered in County Dublin, for example, 

 where E. fluviatilis is extremely common, and where there was abundant 

 opportunity for collecting at different seasons of the year. 



Reference has been made to a sponge from the Eiver Lahn, near Marburg 

 described by Miiller (27) as a probable variety of E. fluviatilis. In this the 

 spicules are short, thick, smooth oxea, with a central swelling ; they are very 

 similar to the spicules of the sponges from Ballyscanlan Lough (PI. I, fig. 5). 

 In addition, the Eiver Lahn sponge possesses a number of scattered amphidiscs 

 like those of E. fluviatilis ; some of them are rather abnormal in shape, but 

 similar forms are often found in quite typical examples of that species. 



Wierzejski (56), writing on the abnormalities of the spicules in the 

 Spongillidae, refers to Miiller's specimen, and says that he has uo doubt but 

 that it is an abnormal form of Ephydatia. He refers also to the fact that when 

 abundant material of any of the European Spongillidae is examined, many 

 abnormalities of the various kinds of spicules are to be seen, and sometimes 

 these abnormal spicides are so predominant that one seems to see new 

 varieties, or even new genera. 



Localities. 



Waterford. — Ballyscanlan L. near Tramore. 



TiPPERARY.— L.Derg in Barrett's Bay.dredged at 14feet(coll. E. Southern). 



EoscoMMON. — Oakport L. and E. Boyle at Cootehill. 



Galway. — L. Eea (as E. MiV.lcri, 21), and recently collected on several 

 occasions in the lake by E. A. Phillips. 



Sligo. — L. Gill at Hock wood (as E. Mulleri, 43), Glencar L., and 

 Drumcliff E. 



Leitrim.— L. Gill at O'Eorke's Castle (as E. Miitlcri, 43). 



Fermanagh. — L. Erne off Caklragh Island and Eagle Island (coll. JIajor 

 Trevelyan), E. Erne at Enniskillen (coll. E. Welch). 



Ephydatia Miilleri Lieberkiibii. I'l. XXVIII, fig. L 

 Ephydatia Miilleri is apparently the rarest of Mie fresh-water sponges 

 found ill Ireland, only two uiulnnbtcd speciinciis having been collected within 



