255 



THE BRITISH NATURALIST. [December 



handful," not found in the mud, as is the typical shell. I have taken 

 a few examples of this variety under dense masses of weeds where 

 no mud existed, and I have very pale examples of the var. pisidoides 

 which were literally shovelled out of the filters at Clumber Lake. 



Heaps of Stones and Rubbish.- Mr. J. Whitwham, writes: 

 "I found specimens of this variety" (Hyalinia excavata var. vitrina) 

 " inhabiting exclusively heaps of stone, cinders, and other refuse. All 

 specimens taken since that time have evinced an invariable partiality 

 for a similar habitat." 



The Rev. S. S. Pearce says, of Vertigo edentula var. columella. 

 " A few specimens after a (iiligent search among the loose stones and 

 rubble." " The typical form not taken with this variety." It seems 

 possible that such environment may have a disturbing influence on 

 some species, perhaps not m the same direction in all. 



Dr. Jeffrey says, of varieties, " they are all off-shoots of species, 

 and originate in some peculiarity of climate, situation, composition of 

 soil, or water which they inhabit ; the nature and supply of food, and 

 various other conditions." He also says " varieties are of two kinds 

 — permanent and local." 



Mr. C. Ashford suggests the possibility of "continued peculiarity 

 of surroundings producing a cumulative effect upon successive 

 generations," and writing of a variety of H . vivgata previously referred 

 to, says, "these facts confirm the opinion that such peculiarities are 

 hereditary." 



Regarding white varieties I find the following notices. Dr. A. 

 Brot records in 1877, the finding in Switzerland of white varieties of 

 H. lapicida, oi H. pomatia, and of H. nemoralis associated, and of 

 H. sylvatica and its var. Alpicola. 



Mr. W. Jeffery remarks, the abundance of Ancylus Jluviatilis in a 

 stream issuing from the chalk hills, all white. I have seen other 

 accounts of this shell of a similar nature, but cannot now find the 

 reference. The writer last quoted, in a letter accompanying examples 

 of the white variety of Planovbis coniens, sent for exhibition at one of 

 the meetings of the Conchological Society, remarks that he "got 

 some specimens of F. coviieus last year from near Arundle, of the 

 ordinary horn colour, and bred the two small white ones from them. 

 On revisiting tlie locality this year, I got the larger specimen, which 

 I think, clearly establishes tlie fact of that variety being found there ; 

 and at the sarne time shows that is irregularly bred from the usual 

 type." 



Mr. C. P. Gloyne relates that he received over fifty specimens of 

 ClaiLsiiia tridciis, from Porto Rico, all alike as two peas. "This was 



