56 



ZOOLOGICAL 



ORDER DIPTERA. 



K7 



CULICIDiE (Gnats or Mosquitoes). Plate 35, Map ii. 



Since the remarkable discovery was made that certain insects of this 

 family play an important role in the dissemination of certain tropical 

 diseases, such as malaria, yellow fever, &c, much attention has been bestowed 

 upon them. From this increased activity, a much better knowledge of their 

 distribution has been obtained, while the number of described species has 

 been augmented to a remarkable degree. At the present day fully 500 

 species are known, distributed among about 70 genera. They are found in 

 every part of the world, Europe possessing about 50 species and North 

 America about 40. In Britain 26 species have been recorded, and some of 

 them are found in all parts of our islands. Anopheles, whose distribution is 

 shown separately on the Map, is a genus comprising about 17 species, at 

 least two of which (A. maadipennis and bifnrcatus) are known to be 

 carriers of the parasite which causes malaria. Stegomyia (also shown on 

 the Map) is likewise an important genus. About 20 species are known, 

 one of which (S. fasciata) is the sole agent in the dissemination of that 

 scourge of the Tropics, yellow fever. 



TABANID.E (Horse-Flies, Clegs, &c). Plate 35, Map iii. 



This family is composed of about 1600 species, some of which are among 

 the bulkiest of known Diptera or Two-winged Plies. They are found in all 

 parts of the world, and are all more or less addicted to blood-sucking, but 

 this habit is confined to the members of the female sex. About 200 species 

 inhabit the Palsearctic Region, about the same number the Nearctic Region, 

 and about 300 the Ethiopian. Britain possesses 25, which are placed in 

 the five genera Ilsematopota, Therioplectes, Atylotus, Tabanus and Chrysops. 



SYEPHID^I (Hoverer Flies). Plate 35, Map iii. 



The flies of this family are among the most attractive in appearance of 

 all the Diptera, their bodies being often elegantly adorned with bands and 

 spots of yellow, or covered with brightly coloured hair. Their popular 

 name is due to their interesting habit of hovering in the air apparently 

 quite motionless, while if disturbed they dart off with lightning-like rapidity, 

 and after a short time return again to hover hawk-like at the same spot. 

 Fully 2500 species are known, and these are found in every part of the 

 globe. Over 300 occur in North America, about 600 in Europe, and 200 

 in Britain. 



GLOSSINA (Tsetse Flies). Plate 35, Map iii. 



This genus of flies, belonging to the family Muscidse, has of recent years 

 sprung into much prominence, owing to the fact that at least one of its 

 species (Glossina palpalis) has been proved to convey the parasite which 

 causes the dreadful African disease known as "sleeping sickness," 

 while another (G. morsitans) is the carrier of the parasite which produces 

 " Nagana " or « fly-disease," so destructive to horses, cattle and other domestic 

 animals. Fortunately for the rest of the world this genus is practically 

 confined to tropical Africa. Ten species have been described, but only the 

 two mentioned have been proved to assist in the dissemination of disease. 



ORDER HEMIPTERA. 



COCCIDJE (Scale Insects). Plate 35, Map iv. 



In this important family about 1500 distinct species have been described. 

 They are of universal distribution, and in some countries are of the greatest 

 importance from the economic point of view, inasmuch as they are probably 

 more destructive to the various fruit and other crops cultivated by man than 

 any other group of insects. Nearly 400 species are found in North 

 America, one of the best-known being the notorious " San Jose Scale " 

 which is a most destructive pest in California and other parts of the 

 United States. On the other hand, certain members of this family produce 

 wax and other materials of much use to man. Lac, cochineal, and axin, 

 the latter a substance used externally in medicine, are examples. 



ORDER NEUR0PTERA. 



MYRMELEONTIDiE (Ant-Lions). Plate 35, Map iv. 



About 300 species of Ant-Lions are known at the present day These 

 range over the greater part of the world, but are more abundant in the 

 warmer regions. Although entirely absent from Britain, yet they occur 

 on the continent of Europe, practically as far north as the Arctic Circle 

 Some of the forms inhabiting the Ethiopian and other regions are quite 

 handsome insects, with an expansion of wing of four inches or more. 



TERMITIM (Termites or White-Ants). Plate 35, Map iv. 



These insects are of much interest, both on account of their remarkable 

 nests and also because of the wonderful details which have been ascertained 

 respecting their social life. Their habitations, built of earth, wood, or other 

 material, sometimes reach a height of 15 to 20 feet, and in such cases 

 form conspicuous objects in the landscape. About 350 species have been 

 described but this number is probably only a small proportion of those 

 which actually exist. From their habit of eating wood they become in 

 some countries exceedingly destructive to furniture and even whole build- 

 ings. These msects are very widely distributed, being mainly found in the 

 warmer regions of the globe. Few species occur in North Imerica or in 

 Europe, while they are quite absent from Britain. 



ODONATA (Dragon-Flies). Plate 35, Map v. 



These handsome and attractive insects are universally distributed b 

 attain their greatest variety in the warmer regions of the earth. Abo t 

 2000 species are known at the present day, and these are arranged in tw 

 principal divisions according to the relative size of the fore and hind wino\ 

 while about seven smaller groups or sub-families may be recognised. Abo & t 

 300 species occur in North America, and just over 100 in Europe. Brita" 

 possesses 40 which are truly native, and some of these are fairly famili 

 objects, attracting attention either by their beautiful and vivid colours 

 by their large size and rapid and powerful flight. 



ORDER TRICHOPTERA. 



TRICHOPTERA (Caddis-Flies). Plate 35, Map v. 



The Caddis-flies in their adult state are moth-like insects, usually seen 

 in the neighbourhood of streams and lakes. Their larvae are well known 

 and of much interest, from the wonderful nature of their habitations which 

 are in the form of more or less cylindrical, and sometimes spiral cases built 

 of tiny stones, grains of sand, fragments of weed, or other materials 

 About 1300 species have been described up to the present day, and these 

 are grouped into 13 distinct families. Some 150 occur in North America 

 500 in Europe, and 150 in Britain, but all these numbers will probably be 

 much augmented when the group receives more attention. 



ORDER ORTHOPTERA. 



LOCUSTIDJE (Green Grasshoppers, &c). Plate 35, Map v. 



The Locustidse, sometimes called Phasgonuridse, are distinguished from 

 their relatives, the Acrididse, chiefly by the length and delicacy of their 

 antennae, which are composed of a large number (always more than 30) 

 joints. They are of universal distribution, but most abundant in warm 

 countries. In the most recent catalogue the names of about 3200 species 

 are given, and these are distributed among no fewer than 694 genera and 

 24 sub-families. Only nine or ten species occur in Britain, and the majority 

 of these are confined to the extreme south of England. 



ACRIDIDSE (Locusts). Plate 35, Map vi. 



A strange confusion exists between the popular and scientific names of 

 this and the preceding family. Thus, the true Locusts are not Locustidse, 

 but Acrididse, while the term Grasshopper is equally unsatisfactory. The 

 members of the present family may, however, be conveniently known as 

 "Short-homed Grasshoppers," in accordance with their most prominent 

 characteristic, namely, their relatively short antennas, consisting of less 

 than 30 joints. Like the Locustidse these insects are universally dis- 

 tributed, but the species are more numerous, over 4250 having been 

 described. For the reception of this multitude of forms, about 840 genera 

 have been founded, arranged in 12 sub-families. Only 11 species are found 

 in Britain, but those of the genera Stenobothrus and Gomphocerus are 

 tolerably common. 



PHASMID.E (Stick and Leaf Insects). Plate 35, Map vi. 



The Phasmidse are, in general, the most extraordinary-looking of all 

 insects, resembling twigs, green or withered leaves, or other parts of plants. 

 They are widely spread over the globe, but are more abundant in the 

 tropical portion. About 950 species are known, which are arranged in 

 about 200 genera and 16 sub-families. About a dozen species are found 

 in North America, and four or five in Europe, where they are mostly con- 

 fined to the south. They are entirely absent from the British Isles, and 

 appear to reach their zenith in Australia. One of the most extraordinary 

 species known is Eurycantha horrida, a creature inhabiting New Guinea 

 and some of the neighbouring islands. 



MANTID.E (Praying Insects). Plate 35, Map vi. 



Like the members of the preceding family, the so-called "Praying 

 Insects" are creatures of extraordinary appearance, and many of them 

 closely resemble leaves and even flowers. They are easily recognised by 

 their powerful spined front pair of legs, which are used for seizing their prey. 

 The name "praying insect "bears allusion to their habit of resting with their 

 front legs held out in a peculiar manner, which is supposed to simulate an 

 attitude of prayer. The distribution of Mantidse is practically the same as that 

 of the Phasmidse. About 830 species have been described, belonging to just 

 over 200 distinct genera, and constituting eight sub-families. Some 20 species 

 occur in North America, but only in the southern portion, while in Europe 

 only about a dozen occur, likewise in the south. The best-known European 

 species, Mantis religiosa, is a frequent inhabitant of southern and central 

 France, but no member of the family occurs in Britain. 



VERTICAL AND LATITUDINAL DISTRIBUTION. 



Plate 36. 



This Plate is an adaptation of one prepared by W. Marshall, which 

 forms No. 60 of Berghaus' Physikalischer Atlas (Abteilung VI, Atlas der 

 Tierverbreitung). No revision of details has been attempted, but a slightly 

 different arrangement has been made of the groups of animals concerned, 

 merely for the sake of clearness. The distribution of marine life, as shown 

 by Marshall, has been omitted for the same reason, but three insets are 

 given to show the bathymetrical range of a few selected families of Fishes 

 and Molluscs. These are based principally upon information given in the 

 Challenger Reports. 



