1926] 
On the Megachile of South Dakota 
165 
tarsi with a conspicuous white hair-fringe; hair on inner side of 
tarsi pale yellow; spurs pale yellow; claws ferruginous basally, 
piceous apically, deeply cleft. 
Abdomen, except for a few short inconspicuous dark hairs 
on segments 3 and 4, white pubescent, shining, the punctures 
quite close but distinct; upper face of first segment very closely 
punctate, the concavity smooth and shining; apical margin of 
segments 2-5 very strongly depressed, especially on segments 4 
and 5 where the apical portion of the disc overhangs somewhat 
the depressed margin, the segments rather strongly depressed 
basally also, giving the discs a rolled appearance; the depressed 
apical margins are white faciate on segments 2-5, white tufts of 
hair being present on the sides of segment 1 ; segment 5 is white 
pubescent on basal half of disc; segment 6 also with white pubes- 
cence basally, rugoso-punctate above the carina, the punctures lar- 
ger and more nearly separate below; carina entire, rounded, with 
irregular crenulations, morphological apex of segment cons- 
picuously carinate on either side and with a small spine at each 
extreme side; seventh segment quite evident, with a triangular 
pointed spine; ventral segments 2 and 3 depressed apically 
similarly as the dorsal segments, all the ventral segments shining, 
distinctly punctate, and with apical fringes of rather long white 
hairs. Length 10 mm. 
. $ . Head broad, eyes not appreciably converging below; 
supraclypeal plate closely punctate, punctures crowded laterally; 
clypeus closely punctate, surface finely tessellated between the 
punctures, apical margin smooth and shining, entire, slightly 
produced laterally; mandibles broad, 4-dentate, a bevelled cut- 
ting edge between the two inner teeth, shining, the punctures 
sparse above, especially apically, faintly reddish near the apex, 
fringed with yellowish hairs below; cheeks shining, but rather 
closely punctured, quite broad; vertex with punctures close 
medially except for an indistinct impunctate median line, the 
punctures more widely separated laterally, deep; ocelli nearer to 
nearest eye than to edge of vertex; antennae black, piceous below; 
pubescence thin, white except for a few short inconspicuous dark 
hairs on the vertex laterally. 
Thorax with pubescence white except for dark hairs on disc 
