t 66 [Pr°c- B.N.F.C., 



The apparent absence from Glencar and Lough Melvin of a 

 few species may be due to lack of work in these river systems, 

 while the blanks in the list of Pisidia are due mainly to the fact 

 that only records founded on specimens verified by Mr. B. B. 

 Woodward are included. I do not think, however, that Pisidium 

 amnicum will ever be found in Lough Gill, Glencar, or Lough 

 Melvin. The sign ? is placed where the species is almost certain 

 of occurrence, but where I have no record of its having been 

 found. 



The most remarkable features of the distribution in the above 

 table are — 



Firstly. — The absence of Planorbis vortex from Lough 

 Melvin. 



Secondly. — The presence of Planorbis carinatus in Lough 

 Melvin and its absence from Glencar and Lough Gill. 



Thirdly. — The absence of Neritina fluviatilis from Loughs 

 Melvin and Erne. 



Fourthly. — The poverty of the list from Lough Melvin, com- 

 pared with that from Lough Gill, which lake it very much 

 resembles from the point of view of a molluscan habitat. 



Lough Melvin appears to contain a very impoverished Lough 

 Erne fauna, while the relationship between Glencar and Lough 

 Gill is apparent also, but in a lesser degree, fewer species being 

 absent from Glencar. 



All the species recorded from the above four river basins are 



found in the basin of the Shannon. 



a. w. s. 



Myriopoda. — The Centipedes and Millepedes collected 

 during the excursion were submitted to Mr. C. M. Selbie, B.Sc, 

 who reports that the following species were obtained : — From 

 Co. Leitrim — *Lithobius forficatus, L. variegatus, *Geophilus 

 proximus, *G. carpophagus, *G. Iruncorum, *Po/ydesmus 

 gallicus, *P. complanatus, *P. denticulatus, Brachydesmus superus, 

 * Craspedosoma rawlinsi, Atractosoma poiydesmoides, Glomeris 



