232 Rev. F. D, Morice on Armatures, etc. of Andrenn . 



less adjacent, while the ' processes ' are parted at their bases 

 by a Avidc interval containing the sagittte, etc., but arch 

 over towards each other more or less strongly, so that 

 their apices often meet or even cross, hiding the tips of the 

 sagittal. It may be noted, too, that this arching creases or 

 ' dogs-ears ' them in various ways, according to the 

 particular species under examination. 



The 8th segment has a transverse naked base, rather thin 

 and transparent, especially at the sides, convex in the ventral 

 and concave in the dorsal view. This ' basal plate,' as it 

 may be called, lies just at the back of the stipites (to which 

 it often adheres in dissections) and covers the gap between 

 them. Beyond it, i.e., towards the apex, the segment con- 

 stricts into a sort of narrow ' process,' and at the same 

 time descends (more or less rapidly) at first, but is after- 

 wards usually again geniculated upwards (Plate VI, Fig. la 

 x). At and above the geniculation the process is always 

 more or less pilose on the ventral side, and lies exactly be- 

 neath the sagittse, which it seems to cover and shelter 

 from below ; the deflexed apices of these organs just reach 

 and rest upon it a little before its apex. Down the centre 

 of the plate, and nearly all through the process, the segment 

 is distinctly thickened (dorsally, i.e., towards the armature) 

 and also (perhaps in consequence) generally darker in 

 colour. The thickening ends, often rather abruptly, a 

 little before the actual apex (which is sometimes pale and 

 transparent). Seen laterally, this produces the effect of a 

 more or less distinct subapical tooth (Plate VI, Fig. la y). 



The 7th segment is in form a transverse crescent, gener- 

 ally notched in the middle of its exterior or convex 

 margin. It covers a part only of the 8th, lying across it in 

 such a way that the constricted " process " of the 8th fits 

 into and fills its notch, just before the geniculation, while 

 the pilose part beyond, and most of the basal plate, are 

 left uncovered. The sides of the " notch " bear each a 

 little fringe or pencil of diagonally-pointing hairs, and are 

 sometimes produced into definite teeth. This segment 

 (except its actual apex) and the base of the 8th lie con- 

 cealed under the 6th — the apical margins of the three 

 segments in part nearly coinciding. The whole 7th seg- 

 ment is thin and frail, causing much trouble in dissection ; 

 it generally sticks pretty tightly to the 6th, and sometimes 

 its notch hangs closely about the " neck '' of the 8th, so 

 that between the two it is very liable to get torn in pieces. 



