The observations of Mr. W. E. Collinge[90] do not at all agree with those of Mr. Lowe, with regard to the mode in which land Mollusca enlarge their shells. He bred and reared most of the commoner forms of _Helix_ and also _Clausilia rugosa_, but never saw them bury any part of their shell when enlarging it. While admitting that they may increase their shells when in holes or burrows of earthworms, he thinks that the process of burying would seriously interfere with the action of the mantle during deposition, and in many cases damage the membranaceous film before the calcareous portion was deposited. Mr. Collinge has found the following species under the surface in winter: _Arion ater_ (3–4 in.), _Agriolimax agrestis_, (6–8 in.), _Hyalinia cellaria_ and _H. alliaria_ (6–8 in.), _Hyalinia glabra_ (5 in.), _Helix aspersa_ (5–6 in.), _H. rufescens_ (4–6 in.), _H. rotundata_ (4–5 in.), _H. hispida_ (7 in.), _Buliminus obscurus_ (4–6 in.), _B. montanus_[91] (24 in.), and the following in summer, _Hyalinia cellaria_ and _alliaria_ (6–8 in.), _Helix rotundata_ (4–5 in.), _Balea perversa_ (6–8 in.), _Cyclostoma elegans_ (3–4 in.). The same author has found the following species of fresh-water Mollusca living in hard dry mud: _Sphaerium corneum_ (3–14 in.), _S. rivicola_ (5–6 in.), _S. lacustre_ (10–14 in.), all the British species of _Pisidium_ (4–12 in.), _Limnaea truncatula_ (18 in., a single specimen). All our species of _Unio_, _Anodonta_, _Bithynia_, and _Paludina_ bury themselves habitually in fine or thick wet mud, to a depth of from 4 to 14 inches. This burying propensity on the part of Mollusca has been known to play its part in detecting fraud. When my friend Mr. E. L. Layard was administering justice in Ceylon, a native landowner on a small scale complained to him of the conduct of his neighbour, who had, during his absence from home, diverted a small watercourse, which ran between their holdings, in such a way as to filch a certain portion of the land. The offender had filled up and obliterated the ancient course of the stream, and protested that it had never run but in its present bed. Mr. Layard promptly had a trench sunk across what was said to be the old course, and the discovery of numerous _living Ampullaria_, buried in the mud, confirmed the story of one of the litigants and confounded the other.[92]