2l6 JOURNAL OF CONCHOLOGY, VOL. I3, NO. 7, JULY, I9II. 



Mr. Herbert King, M.Sc, the Borough Analyst of Scarborough, has 

 been kind enough at my request to analyse both niolluscand nullipore, 

 and he tells me the shell and its contents gave 49% of animal matter 

 and 51% per cent, of organic; and the Polythainnien in two examples 

 gave 60% and 57% or an average of 58*5% of mineral matter. He 

 adds: "The metals present in the ash of each were similar, as 

 one would expect, viz. : calcium, sodium, aluminium and a small 

 trace of iron. A very minute quantity of what might be manganese 

 was present, but with the small amount of material at disposal this 

 could not be satisfactorily confirmed, even with borax bead nor as 

 permanganate.'' 



Presumably Aaiuea feeds on the nullipore, hence its abundance on 

 it. When an adult Aci/icea is taken off the nullipore, it is found that 

 the colour of the nullipore covered by the shell has disappeared, 

 which I think makes it probable that Aciiicea^ like Patella, returns to 

 exactly the same place after feeding. 



I have written to three correspondents who have taken this species 

 alive in different parts of the country, but except in the case of Prof. 

 Herdman who tells me he knows it in similar situations, and remarks 

 how very like it is to its background, I have not heard of others who 

 have found it similarly placed. Possibly now that attention has been 

 drawn to it, instances may be found elsewhere. 



I may add that Tonicella ruder (Lowe) also occurs on this nullipore, 

 on which it is almost invisible. 



New County Records of Pisidium. — 'Mmox\t\.\\shue.— P.personalutn Malm, 

 near Arthog ; P. obttisale Pfr. , Barmouth Junction. Montgomeryshire — P. obtiisale 

 Pfr. , near Glandyh Junction. Cardiganshire — P. personatiiiit Mahn, Lyffnant 

 Valley; P. subtnincaiitin Malm,- Glandyfi. Middlesex — P. persotiattim Mahn, 

 Ilampstead. East Suffoll< — P. piilchellnin Jenyns, Soulhwold. I have to thank 

 Mr. B. B. Woodward for kindly identifying P. personalutii. — J. E. CooPEK [Read 

 before the Society, Eeb. il, 1911). 



