FLIES AND FLEAS. 53 



Among the Carpenter-bees, Coptorthosoma, from Ceylon should 

 be noticed. The females of this bee have a cavity on the upper side 

 at the base of the abdomen, and in this cavity are constantly found 

 a mite, Greenia. The object of choosing this curious abode is at 

 present unknown. 



Another object of great interest in this case is the spoon-shaped 

 entrance tube made by a very small stingless bee, Trigona collina, 

 from Singapore, presented by Mr. H. N. Ridley. These bees live 

 together in enormous numbers. They build in the hollows of old 

 trees. The nest consists of an irregular mass of large cells and 

 galleries made of resin. In the centre are the small breeding cells 

 made of wax. Many of the large cavities in the resinous part are 

 filled with pollen, stored for food. The entrance to the nest is by 

 means of a tube such as that shown in the Table-case. The resin of 

 which these nests are built is collected by these small bees in such 

 large quantities that the masses are of commercial value.' It is 

 known in the market as " damar." In Burmah it is called " poonyet " 

 or " pwai-nyet." A large mass weighing fifteen pounds is shown at 

 the bottom of Wall-case 16. 



Order DIPTERA. 



The insects of this order are called Flies, with which the Fleas 

 are associated. They undergo a complete metamorphosis. The 

 perfect insect has the head free, the attachment to the thorax being 

 very slender. The thorax is compact ; the union of the prothorax, 

 mesothorax and metathorax is so complete that their limits are to a 

 certain extent problematical. Two styles of mouth parts are met 

 with. The first in which the mandibles and maxillae are very long 

 and needle-shaped, enclosed in the labium which forms a sheath, as in 

 the gnats ; the second in which the mandibles and maxillae are not 

 manifest, whilst the labium is a soft fleshy organ, concealed in the 

 mouth cavity when at rest, but, being jointed, is capable of being 

 extended when the insect is feeding. The Common House-fly is a 

 good example. 



The larvae are for the most part without legs, grubs or maggots, 

 with very small heads. The larvae of gnats, however, which live in 

 water have large heads and well-developed mouth parts, and are of 

 quite a different character. They are extremely active. Drawings 

 of some of the most interesting species are exhibited in Table-case 56. 

 The pupge are very variable. 



