156 REPORT — 1859. 



those should be selected among the specimens, whose trains are already retracted. 

 When deposited in the aquarium undamaged, C. pileus thrives remarkably well, and 

 is one of the most joyous of creatures in confinement. Its natural food is prawns, 

 and a rarer kind of shrimps — not the common shrimp. Beroe is the natural food of 

 Cydippe ; but if placed in the same vessel, the interesting spectacle will be afforded 

 of the deglutition by one transparent animal of another equally pellucid. 



On the Distribution of British Butterflies. By Mr. H. T. Stainton. 



Among the insect tribes, the ' Scale-wings,' or order Lepidoptera, has always 

 attracted a considerable amount of attention ; the variety and beauty of the butterfly 

 tribe is a matter of notoriety. The order Lepidoptera includes two great divisions, 

 butterflies and moths ; the former group all fly by day, whereas most of the moths 

 are nocturnal in their habits. It has been calculated that there are not less than 

 50,000 different species of Lepidoptera on the globe. More than 3000 species of 

 butterflies are already known ; and it has been computed that the moths are sixteen 

 times as numerous. 



In this country the proportion of moths is much greater, being nearly thirty to 

 one ; but then we are remarkable throughout Europe for our poverty in butterflies. 

 As already observed, in the whole world 3000 species of butterflies are already 

 known ; of these only one-tenth occur in Europe, the tropical parts of Asia and 

 America being by far the most numerously populated with this beautiful tribe of 

 insects. 



In central Europe or Germany 186 species of butterflies have been observed, the 

 remaining 120 European species being peculiar to Spain, Italy, Greece, Russia, or 

 Lapland. Of the German species, 94 occur in Belgium, but only 65 in Eng- 

 land — though we possess one species, Erebia Cassiope, which does not occur in 

 Belgium. 



All the British butterflies occur in England, but little more than half (only 33) 

 are found in Scotland, and scarcely more in Ireland. 



Twenty-five species may be considered as generally distributed and common ; but 

 it should not be understood that these are everywhere to be met with, but simply 

 that their geographical range is not limited, and that where they find suitable locali- 

 ties we may expect to meet with them from Norfolk to Killarney, and from the Isle 

 of Wight to Caithness. Some frequent gardens, some meadows, some heaths, some 

 woods, and some hedgerows and lanes. 



Twenty-five other species, which all occur in the south-east of England, thin out 

 as we advance northwards and westwards ; only five of them occurring in Scotland, 

 and only fourteen in Ireland. 



Three species, two of which are common in the mountainous parts of Scotland, 

 do not occur at all in the south of England. 



Seven species are local to particular limited districts in the Midland Counties or 

 the south of England. 



Three species of rare occurrence in this country must be looked upon as stragglers 

 from the Continent ; one of them, Vanessa Antiopa, has occurred in the south-west 

 of Scotland and at Dunbar. 



Two other species, which formerly occurred in restricted English localities, now 

 appear to be extinct there. 



It has been observed by Dr. Speyer, who has devoted considerable time to the 

 subject of the geographical distribution of the butterflies of Germany, that the 

 number of species there decreases from east to west and from south to north ; but 

 the latter circumstance is partly owing to the configuration of the country, the Alps 

 being particularly rich in butterflies. 



That butterflies are not regularly distributed according to latitude, is evinced by 

 the simple fact, that in Lapland, which is situated considerably further north than 

 the Shetland Isles, they enumerate seventy-seven species, whereas Scotland only 

 boasts of thirty-three. Silesia, on the eastern side of Germany, but in the same 

 latitude as Belgium, has 124 species, about one-third more than Belgium, which 

 only numbers ninety-four. Berlin, though further north than Paris, has more 



