Belonging to the same tribe (Nephropsidea) as the Lobsters are the fresh-water Crayfishes. The English Crayfish (_Astacus pallipes_) is common in many rivers as far north as Lancashire, and in some parts of Ireland, but is not found in Scotland. It is not much esteemed for the table, and although small numbers are sent to Billingsgate, chiefly from Leicestershire, they are said to be used only for garnishing dishes. The same species occurs on the Continent of Europe, chiefly in the west and south (France, Germany, Switzerland, Spain, Italy, and the Balkan Peninsula). It is known in France as "Écrevisse à pattes blanches" (from the whitish colour of the under-side of the large claws), and in Germany as "Steinkrebs," and is distinguished, among other characters, by the shape of the rostrum (Fig. 77, B), which has a tooth on each side close to the point. Far more important as an article of food is the larger _Astacus fluviatilis_, the "Écrevisse à pattes rouges" or "Edelkrebs," which is found in France, Germany, Austria, Southern Sweden, Russia, etc. In this species the under-side of the large claws is generally of a fine red colour, and the rostrum (Fig. 77, A) has a pair of side-teeth about the middle of its length, and a long slender point. The red-clawed Crayfish is an important article of commerce on the Continent, and is sent to the London market in considerable numbers, chiefly from Germany and South-West Russia. In France it is cultivated for the market in "Crayfish farms" on a large scale. [Illustration: FIG. 77--ROSTRUM AND FORE PART OF CARAPACE, SEEN FROM ABOVE, OF (A) RED-CLAWED CRAYFISH (_Astacus fluviatilis_) AND (B) WHITE-CLAWED OR ENGLISH CRAYFISH (_Astacus pallipes_)] A species of Crayfish (_A. leptodactylus_) occurring in the Lower Danube and in other rivers flowing into the Black Sea sometimes finds its way to the London market, although it is less valued than the red-clawed species. It is distinguished by its long and slender claws, by the spiny edges of the rostrum, and by other characters. A fourth species (_A. torrentium_), occurring chiefly in Central Europe, is very closely allied to _A. pallipes_, and, like it, is of little value for the table. Within the last thirty years the Crayfish fisheries of Western Europe have suffered heavily from outbreaks of an epidemic disease which has all but exterminated these animals in certain districts. In this country it is said to be responsible for the almost complete disappearance of Crayfish from localities where they were formerly plentiful, as, for instance, in the neighbourhood of Oxford. The cause of the disease is believed to be a protozoan parasite belonging to the group Myxosporidia.