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SANTAREM 



weather, and the previous layer was sometimes not quite 

 dry when the new coating was added. The whole struc- 

 ture takes about a week to complete. I left the place 

 before the gay little builder had quite finished her task : 

 she did not accompany the canoe, although we moved 

 along the bank of the river very slowly. On opening 

 closed nests of this species, which are common in the 

 neighbourhood of Mahica, I always found them to be 

 stocked with small spiders of the genus Gastracantha, in 

 the usual half-dead state to which the mother wasps re- 

 duce the insects which are to serve as food for their progeny. 



Besides the Pelopaeus there were three or four kinds of 

 Trypoxylon, a genus also found in Europe, and which 

 some Naturalists have supposed to be parasitic, because 

 the legs are not furnished with the usual row of strong 

 bristles for digging, characteristic of the family to which 

 it belongs. The species of Trypoxylon, however, are all 

 building wasps ; two of them which I observed (T. albi- 

 tarse and an undescribed species) provision their nests 

 with spiders, a third (T. aurifrons) with small caterpillars. 

 Their habits are similar to those of the Pelopaeus ; namely, 

 they carry off the clay in their mandibles, and have a 

 different song when they hasten away with the burthen, 

 to that which they sing whilst at work. Trypoxylon 

 albitarse, which is a large black kind, three-quarters of 

 an inch in length, makes a tremendous fuss whilst building 

 its cell. It often chooses the walls or doors of chambers 

 for this purpose, and when two or three are at work in 

 the same place their loud humming keeps the house in an 

 uproar. The cell is a tubular structure about three inches 

 in length. T. aurifrons, a much smaller species, makes a 

 neat little nest shaped like a carafe ; building rows of 

 them together in the corners of verandahs. 



But the most numerous and interesting of the clay 

 artificers are the workers of a species of social bee, the 

 Melipona fasciculata. The Meliponae in tropical America 

 take the place of the true Apides, to which the European 

 hive-bee belongs, and which are here unknown ; they are 

 generally much smaller insects than the hive-bees and have 

 no sting. The M. fasciculata is about a third shorter 

 than the Apis mellifica : its colonies are composed of an 

 immense number of individuals ; the workers are gener- 

 ally seen collecting pollen in the same way as other bees, 

 but great numbers are employed gathering clay. The 



