THE NATURALIST. 



in the river, though somewhat 

 sparingly ; and that very few now 

 contained pearls. To remove all 

 doubt as to their existence several 

 half shells were shown to me. These 

 are turned to a useful account by the 

 thrifty Manx housewives who use 

 them for scoops, and for scraping out 

 the nutritious morsels of the porridge 

 pot. In the course of my enquiries, 

 I met with an old gentleman who not 

 only gave me some curious facts as 

 to the habits of this Unio, but also 

 procured me some fine living speci- 

 mens, one of which contained a small 

 but not very brilliant pearl. This 

 was Mr. Gates, of Kirk Braddan, 

 through whose farm the Dhoo runs. 

 He is a good specimen of an honest 

 warm-hearted Manx fai'mer, and I 

 trust caught no cold in catching me 

 *' black-mussels." Unio margaritiferus 

 loves to lurk in the shallow and 

 quick-running parts of the river, 

 amongst the gravel and small stones, 

 and as the shell generally burrows 

 in a somewhat oblique position only 

 a small portion of it is visible, and 

 this being black and not unfre- 

 quently covered with a little moss, 

 requires a well practised eye to 

 detect it amongst the surrounding 

 stones, for one of which it may be 

 easily mistaken. It seems very sus- 

 ceptible to the action of light, for 

 under the full blaze of a bright mid- 

 day sun it emerges more out of the 

 gravel and protruding a portion of 



its body through the partly opened 

 valves of the shell is the more readily 

 distinguished. If the sun becomes 

 overcast or the water above the 

 shell be muddy it immediately 

 closes, and, to a person not well 

 conversant with it, is then very 

 difficult to find. The country 

 lads generally select a bright noon- 

 day to look for them, and take them 

 either by wading, or by thrusting the 

 end of a long slender rod into the 

 half open shell, which instantly 

 closes upon it and it is then dragged 

 to land. I shall probably be visiting 

 the Isle of Man again in September, 

 and hope a few more specimens will 

 be ready for me, which I shall 

 have much pleasure in distributing 

 amongst such Conchologists as may 

 want them. I may observe that I 

 found about fifty specimens of Pwpa 

 umbilicata congregated in a single 

 tuft of grass growing upon one of the 

 "rope-stones" of a barn at Balla- 

 doole, near Castletown ; and that 

 from another small tuft of coarse 

 grass growing upon the toj) of a dry 

 wall near Kentraugh, I procured 

 twenty specimens oi Helix umhilicata. 

 Baleafragilis was tolerably abundant 

 under the top stones of a shaded wall 

 between Douglas and Kirk Onchan ; 

 near the latter place I found a 

 singularly contorted specimen of 

 Helix nemoralis. — John Dixon, 

 General Infirmary, Leeds. 



