Figures 19–22 in Observations on Antennal Morphology in Diptera, with Particular Reference to the Articular Surfaces between Segments 2 and 3 in the Cyclorrhapha

Figures 19–22. Details of antennal structure in lower brachycerans. (19) Spaniopsis clelandi Ferguson (fam. Rhagionidae), left antennal segs. 1 and 2, after removal of seg. 3, lateral view. (20) The same, detail of distal articular surface, showing button. (21) Daptolestes sp. (fam. Asilidae), distal view of antennae after removal of segs. 3, showing button. (22) The same, part of distal articular surface (left antenna) including button. bu, pedicellar button.