Subsection 3. Dasygasters (convey pollen on the belly).
All with two submarginal cells to the wings.
Genus 19. Megachile, Latreille. (Leaf-cutters.)
Apis ** c 2 α, Kirby.
([Plate XII.] fig. 2 and 3 ♂♀.)
Gen. Char.: Head as wide as the thorax, flat and broad on the vertex, where, on the anterior edge, the ocelli are disposed in a triangle; antennæ shortish, filiform, geniculated; scape about as long as two first joints of flagellum, which increases both in length of joints and their substance from base to apex, the terminal one being the longest, and longitudinally compressed; face and clypeus very pubescent, concealing their divisions; clypeus transversely lunulate, scarcely convex; labrum longitudinally slightly convex and oblong, with the sides parallel; mandibles broad, widening outwardly, irregularly quadridental, the two inner teeth obtuse; cibarial apparatus moderately long; tongue more than twice the length of the labium, tapering from the base to the apex, where it terminates in a minute knob; paraglossæ very short, scarcely one-sixth the length of the tongue, coadunate at the base and acuminate at the apex, where, in repose, they lap round the base of the tongue; labial palpi three-fourths the length of the tongue, the two basal joints long, subequal, membranous, linear, slightly tapering to the acute apex of the second, where the third subclavate joint articulates just before its termination, and conterminous with which is the fourth, shorter than the third, but also subclavate; labium not quite half the length of the tongue, with a long subobtuse process in the centre of its inosculation; maxillæ subhastate, and very acuminate, nearly as long as the tongue; maxillary palpi very short, two-jointed, the basal joint the shortest, and the terminal one obtuse at its apex, where it is furnished with brief setæ. Thorax subglobose, pubescent, the pubescence almost concealing its divisions; prothorax inconspicuous; mesothorax convex, subglabrous on the disk; scutellum, lunulate, convex; metathorax truncated; wings with two submarginal cells, the commencement of a third slightly indicated, the two complete ones nearly equal, the second of which receives both the recurrent nervures, one towards each extremity; legs robust, very setose; the posterior tibiæ slightly curved longitudinally, concavo-convex, broad at the extremity; all the plantæ as long as their tibiæ and as broad at the base but decreasing at the apex to the width of the following tarsal joints, the anterior pair fimbriated externally, and the posterior pair clothed, on the inner surface, with a dense, short brush, the three following joints short, subequal, the claw-joint as long as the three, and the claws with a broad basal inner tooth. Abdomen ovate, with parallel sides, convex above, truncated and concave at its base to fit the metathorax, distended horizontally in length, or with an upward curve, the four first segments slightly constricted, and their edges usually clothed with decumbent down; the terminal segment obtusely pointed and slightly depressed transversely towards its extremity; the ventral segments commencing with the second, clothed with parallel layers of moderately long, straight setæ, which in each parallel are of equal length, but those on the fifth segment are the shortest, upon all of which the insect conveys the pollen it collects.
The FEMALES of the second division of the genus scarcely differ.
The MALES of the first division differ in having the head slightly larger and squarer above; the antennæ very slightly longer; the mandibles more acutely tridentate, with a distinct powerful basal tooth beneath, terminating the concavity of the organ; the anterior femora, tibiæ, and joints of their tarsi, excepting the terminal one, concavo-convex, the four first joints of the latter distended laterally, and edged with a dense fringe of setæ, the distension of these joints is widest at their articulation with the tibiæ and they decline in length to the claw-joint which is long; the claws bifid; the interior claw acute, but remote from the apical one; the posterior femora are very robust, their tibiæ, much curved, robust, almost triangular, and externally very convex; their plantæ, almost glabrous, not so long as the three following joints, externally rather twisted, and beneath furnished with a dense brush of long stiff hair.
In the second division of the genus the males are destitute of the distension of the anterior tarsi, these being instead densely fimbriated externally; the legs in them are much less robust, and more closely resemble those of their females.
NATIVE SPECIES.