FLIES AND FLEAS. 53 



being worked by the bee's mouth that they lose this transparency. 

 Other bees are shown in Table-case 48. 



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 

 examples of a mite, Oreenia. The object of choosing this curious 

 abode is at present unknown. 



Another specimen 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 " darnar." In Burinah 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, and with them 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 and the union of the prothorax, 

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

 certain extent problematical. Two kinds 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, capable of being- 

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

 good example of the second type. 



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

 and with very small heads. A few examples are exhibited in Table- 

 case 49. The larvae of gnats, however, which live in water have large 

 heads and well-developed mouth parts, and are of quite a different 



