92 TJi€ Irish Naturalist. May, 



MHTOPONORTHUS MELANURUS, 

 A Species of Woodlouse New to Ireland. 



BY R. p. SCHARFF, PH.D., M.R.I.A. 



In October last Mr. J. N. Halbert discovered under stones 

 close to high water mark in Knox's Bay, Howth, Co. Dublin, 

 an active little brightly-coloured woodlouse, which seemed 

 to him different from any he was familiar with. He submitted 

 it to Mr. D. R. Pack-Beresford and myself for identification. 

 We both were of opinion that it was new to the Britannic 

 fauna, and that it agreed to some extent with Mr. Budde- 

 Lnnd's description of Uletoponorthus melamiriis^ B.L. Not 

 being quite certain, we sent it to the original describer of the 

 species, Mr. Budde-Lund, for verification, and he kindly con- 

 firmed our identification. 



Only two kinds of Metoponorthus were hitherto known 

 from the British Islands, viz., M. cingendus and M. pniinosns.^ 

 The new species grows to about the same size as Metop07i- 

 orthus cingendus, but the ground colour is darker, while it 

 has a longitudinal series of light yellow spots. On the upper 

 surface of every body segment there is a transverse row of 

 minute white tubercles, the head being dark brown. Thus, 

 b}' the colour alone, the new species is easily distinguishable 

 from the other Britannic species of the genus. But Mr. 

 Budde-Lnnd attaches more importance to the fact that in this 

 species the first pair of pleopods, which are onlj' visible with 

 a good lens, are small in the female and somewhat apart 

 from one another. ^ 



According to Mr. Budde-Lund, Metoponorthus viela^nums 

 has been collected on the shores of the Mediterranean, in the 

 south of France, Italy, Corsica, and Algeria. It is probable, 

 therefore, that this species also occurs on the Atlantic coasts 

 of France and possibly in the south-west of England. At any 

 rate, it is an important and interesting addition to the number 

 of species which Ireland has in common with the Mediter- 

 ranean Region. 



National INIuseuni, Dubhu. 



' vScHARi'F, R. F. --Tlie Irish Woodhce. Irish N'o/iirah'sf, vol. iii., pp. 4-7 

 and 25-29, 1894. 

 - BrDDK-IviNi), G. — Crustacea Isopoda Terrestria, p. t8t, 1885. 



