1. PHILOPOTAMUS INSULARIS. (? A variety of _P. montanus_.)--This can hardly be termed a British species or variety, because, so far as at present known, it is peculiar to the Island of Guernsey. It agrees structurally with _P. montanus_, a species found both in Britain and on the continent, but it differs in its strikingly yellow colour, and less pronounced markings. All the specimens from Guernsey are alike, and resident entomologists assured Mr. McLachlan that no other kind is known. Strange to say, some examples from Jersey differ considerably, resembling the common European and British form. Even should this peculiar variety be at some future time found on the continent it would still be a remarkable fact that the form of insect inhabiting two small islands only twenty miles apart should constantly differ; but as Jersey is between Guernsey and the coast, it seems just possible that the more insular conditions, and perhaps some peculiarity of the soil and water in the former island, have really led to the production or preservation of a well-marked variety of insect. In the first edition of this work two other species were named as then, peculiar to Britain--Setodes argentipunctella and Rhyacophila munda, but both have now been taken on the continent. 2. MESOPHYLAX IMPUNCTATUS, _var._ ZETLANDICUS.--A variety of a South and Central European species, one specimen of which has been found in Dumfriesshire. The variety is distinguished by its small size and dark colour. {356} _Land and Freshwater Shells._--In the first edition of this work four species were noted as being, so far as was then known, exclusively British. Two of these, _Cyclas pisidioides_ (now called _Sphaerium pisidioides_) and _Geomalacus maculosus_, have been discovered on the continent, but the other two remain still apparently confined to these islands; and to these another has been added by the discovery of a new species of Hydrobia in the estuary of the Thames. The peculiar species now stands as follows:-- 1. LIMNEA INVOLUTA.--A pond snail with a small polished amber-coloured shell found only in a small alpine lake and its inflowing stream on Cromagloun mountain near the lakes of Killarney. It was discovered in 1838, and has frequently been obtained since in the same locality. It is sometimes classed as a variety of _Limnea peregra_, and is at all events closely allied to that species. 2. HYDROBIA JENKINSII.--A small shell of the family Rissoidae inhabiting the Thames estuary both in Essex and Kent. It was discovered only a few years ago, and was first described in 1889. 3. ASSIMINEA GRAYANA.--A small estuarine pulmonobranch found on the banks of the Thames between Greenwich and Gravesend, on mud at the roots of aquatic plants. It has been discovered more than sixty years.