THE CANADIAN ENTOMOLOGIST. 31 



A FOSSIL LEAF-CUTTING BEE. 



BY T. D. A. COCKERELL, UNIVERSITY OF COLORADO. 



In the course of our excavations at Florissant, we had found more 

 than once fossil leaves cut as though by Megachile. Yet we did not feel 

 positive that the injury might not have been produced in some other 

 manner, and it was certainly not permissible to assume the former 

 presence of Megachile on such slender evidence. However, in going over 

 the collections of 1907, I now find a veritable leaf-cutting bee, herewith 

 described : 



Megachile pi'ce dicta, n. sp. 



?. — Length (with the head thrust forward) 11 mm.; width of head 

 3, of thorax 4, of abdomen 3V5 mm.; abdomen oval^ its length about 5 

 mm.; the dense ventral scopa can be clearly seen with the compound 

 microscope, and the apical depressions of the segments are visible and 

 quite normal. Head and thorax black, abdomen red. As preserved, the 

 wings are also red, but this is due to a ferruginous infiltration. The 

 abdomen is no doubt stained in the same way, but since it was evidently 

 not black, it was presumably red, as in the Australian M. abdominalis. 

 Smith. Head ana thorax strongly and extremely closely punctured ; 

 punctures on front considerably larger than those on mesothorax ; clypeus 

 densely, punctured ; inner orbits straight, somewhat converging below ; 

 ocelli large, in a curve ; a groove runs downward from the middle ocellus. 

 Anterior wing about 7 mm. long (the tip not visible) ; venation quite 

 normal ; stigma large for a Megachile; marginal cell rather obtusely 

 pointed, away from costa ; basal nervure ending a little behind (apicad 

 of) transverso-medial ; second 'transverso-cubital with a double curve ; 

 second recurrent nervure gently and evenly curved outwards, and ending 

 a little before tip of second submarginal cell, the cell being rounded, not 

 angulate, at its lower outer corner ; lower part of basal nervure quite 

 strongly curved. 



The following measurements are in micromillimeters : 

 Depth of stigma, 238 ; length of marginal cell, 2006 ; width of mar- 

 ginal, 510; length of first submarginal, 1343; of second submarginal, 

 1122; of first discoidal, 1921 ; basal nervure on first s. m. about 340; 

 b. n. on first discoidal, 935 (or rather more, allowing for curve) ; b. n. 

 short oft. m. about 68 ; length of first t. c, 340; origin of first t. c. to 

 insertion of first r. n., 102 ; insertion of first r. n. to insertion of second, 

 986 ; insertion of second r. n. to corner of second s. m. about 68 ; insertion 



January. ipoS 



