122 hey: MOLLUSCA of DERBYSHIRE. 



Vertigo edentula. — I found this species near Buxton, and one 

 in the Pavilion Gardens at Buxton. 



Balea perversa. — Not common here; I have found it near 

 Haddon Hall in the park under bark of fallen trees, also 

 in the London Road Wharf, Derby, probably brought here 

 with timber. 



Clausula rugosa. — Very plentiful throughout the district. 



CI. laminata.— Not a very common shell by any means, 

 although I often take half-a-dozen or so in an hour's hunt 

 near Millers-dale, also at Monsal-dale and Monks-dale. 



Cochlicopa tridens. — I find this shell near Cromford, but 

 not common ; also on Sinfin Moor near Derby. 



C. lubrica. — Very common throughout the district. 



Achat! na acicula. — Although the habits of this little shell 

 are very obscure, it is fairly plentiful in the neighbourhood 

 of Millers-dale and Monsal-dale. 



Carychium minimum. — May be found throughout the dis- 

 trict. I have taken it at Millers-dale, Monsal-dale, Buxton, 

 Bakewell, Matlock, Cromford, Ambergate, Chellaston, 

 Weston, &c. 



♦^♦♦^ 



The Fluid emitted by Limnsea stagnalis. — It is a 



well known fact to collectors that now and again on taking some 

 of this species rather roughly out of the water a pale bluish or 

 purplish coloured emission from the animal can be seen at the 

 mouth of the shell. It is worth knowing in connection with 

 this — as it gives a suggestion as to the character of this emission — 

 that the haemolymph of this species contains a respiratory 

 substance in its composition termed Hsemocyanin which 

 consists of copper united withaproteid. Unoxidised hsemocyanin 

 is colorless ; oxidised hsemocyanin, on the other hand, is bluish, 

 exactly the color of the emission. It seems to me exceedingly 

 probable that this emission — since no gland can be demonstrated 

 to secrete this fluid, on dissection, as in Purpura and Murex 



J.C., vi., July, 1889. 



