﻿NOTES ON THE CELL-MAKING OF MEGACHILE. 101 



of their nests. On capturing two, and comparing them later 

 with specimens in the British Museum, they proved to be the 

 somewhat rare species ligniseca, which I learnt later may be 

 determined with certainty by the habit peculiar to this species 

 of constructing their burrows in solid oak. This branch, which 

 was of oak about 12 ft. long and 8 in. in diameter at its thickest 

 part, had been broken off a tree near by, and had fallen with the 

 thick end resting up in a hedge. The opposite end through 

 resting on the ground had become rotten for about an inch 

 inward, and had been much bored by these insects in former 

 years. 



The plate, taken of a specimen now in the British Museum, 

 shows a nest in the solid part of the branch with the surface- 

 wood removed to expose the six cells, except in the vicinity 

 of the entrance in top left-hand corner of plate, this being 

 closed by a plug or wad of circular pieces of leaf placed one on 

 top of the other to a depth of 2^ in., finishing off flush with the 

 surface of wood and through the outermost pieces of leaf 

 becoming dry and brown requires a very close examination 

 to reveal its existence. 



About fifteen tunnels were examined, which, with two 

 exceptions, took various undulatory courses, in one case run- 

 ning parallel with the surface for about half its length, then 

 abruptly turning at an angle of 40 degrees and striking across 

 the wood to within half an inch of the opposite side. The 

 average length was 6J in. With the exception of one containing 

 seven, each nest was composed of six cells made up of a number 

 of oblong, almost square-ended pieces of leaf firmly fixed together, 

 and tightly fitting the burrows, the form of which they take. 

 The ends are formed by three or four pieces of leaf cut to the 

 shape of the tunnel, and arranged in the same fashion as those 

 used to stop the entrance of burrow. These pieces are worked 

 on to the ends of the cells in a slightly concave form, the end of 

 each cell fitting into that of its predecessor after the manner of a 

 number of thimbles placed within each other, the whole assuming 

 somewhat the appearance of a large jointed green worm. 



Several cells, which I pulled to pieces for the purpose of 

 examination about the end of September, contained full grown 

 larvae spun up in a smooth brown cocoon, the frass in every case 

 being carefully excluded between the sides and posterior end of 

 the cell and cocoon. These cells varied a good deal in size, all 

 the larger ones being slightly flattened on their sides, thus 

 imparting to them a lozenge or oval shape, measuring 10 mm. 

 by 8 mm. across their ends. The length ranged from 12 mm. to 

 17 mm., the smaller specimens being quite cylindrical and much 

 more uniform in construction. As far as I could ascertain, the 

 leaves used appeared to belong to a species of elm, but being in 

 such small pieces, and in many cases cut from the centre of the 



