Studies of North American Bees 79 



This species, described from a single male from Pike's Peak, 

 Colorado, has • been identified by Robertson in material from 

 southern Illinois, and the writer has before him a pair of Illinois 

 specimens determined by Robertson. Two males from Nebraska, 

 one collected at Ashland, May 28, 19 10, on Erigeron phila- 

 delphicus (M. H. Swenk) and the other at South Bend, May 18, 

 191 1, on Fragaria americana (M. H. Swenk), both agree exactly 

 with Cresson's description except that the spots on the pleura 

 are small and round and the base of the first abdominal tergite 

 and first two sternites are not stained with red as described by 

 Cresson; but the male Illinois specimen determined by Robert- 

 son agrees with the Nebraska males in these respects, which are 

 to be regarded as merely slight individual color variations. 

 Along with the first mentioned male (Ashland, May 28, 1910, on 

 Erigeron philadelphicus) , was collected a female which is con- 

 siderably different from the Illinois female and Robertson's de- 

 scription of that sex. It is much smaller (only 8.5 mm. long 

 while the Illinois series is 11-13 mm. long), has no yellow on the 

 posterior orbits (a nearly complete yellow orbital band on 

 Illinois specimens), only a slight yellow stain in middle of lateral 

 face marks (these, together with clypeus above, scape in front, 

 labrum and mandibles usually largely yellow on Illinois speci- 

 mens), the pleural spot, mesoscutellum and legs are red (these 

 usually yellow or largely so in Illinois specimens), the first 

 abdominal tergite has a broad red band bearing a small oval 

 yellow spot on each side (a broad yellow band in Illinois speci- 

 mens), and the bands on tergites 2 and 3 are interrupted with a 

 red line (complete in Illinois specimens). While these differ- 

 ences are rather great for even this variable genus and species, 

 yet the antennal structure, angulated and wholly black propo- 

 deum, puncturation, etc., in fact the whole habitus of the insect, 

 agrees precisely with supcrha, and this, in conjunction with the 

 fact that the specimen was captured in company with the almost 

 typical siiperba ^ above mentioned, lead to the conclusion that 

 this is but a wide color and size variation of superba, and the 

 specimen is so regarded by the writer. 



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