FIELD BOOK OF INSECTS. 



PANURGID^E 



The marginal cell is sharply truncate at the tip and 

 the lower corner has an appendicular vein except in Halic- 

 toides. This genus is often put in a separate family, 

 Dufouridas. It differs from the other genera in also 

 having the labrum free from the mandibles and as large 

 as the clypeus. With the exception of Protandrena,ihere 

 are only two submarginal veins. The stigma is large. 

 The chitin often has yellow markings; the clypeus is 

 hardly protuberant; and the tongue is acute and flat. 

 Macropis (often put in a separate family, Macropidae) 

 has the hind basitarsi as broad as the tibiag. In Perdita 

 (Plate XCIII) the marginal cell is not longer than the 

 stigma ; they are small bees with the head and thorax usually 

 metallic dark green or blue, and the abdomen usually 

 with light, chitinous markings. In Calliopsis (hairy 

 bees, with hairy bands on the abdomen) and Panurginus 

 (abdomen shiny black, unbanded) the marginal cell is 

 relatively longer; the head and thorax are not metallic. 



NOMADID.E 



These bees are usually less than half an inch long; 

 some are almost hairless, with yellow or red, chitinous 

 markings. They are rather wasp-like in appearance and 

 all are "cuckoos," lacking pollen-collecting apparatus 

 and living in the nests of other bees. There are usually 

 three submarginal cells; the first recurrent vein does not 

 meet the first transverse cubital; the first discoidal cell is 

 much longer than the marginal, which is rarely longer 

 than the first two submarginal cells united and not trun- 

 cate; first portion of subdiscoidal vein shorter than the 

 third portion of the discoidal ; clypeus protuberant ; labrum 

 large, free, convex; tongue elongate, slender; eyes extend- 

 ing to, or nearly to, the base of the mandibles. In Nomada 

 (Plate XCIV) the apex of the marginal cell touches the 

 front wing-margin and the abdomen has chitinous bands 

 or spots. In Epeolus (maxillary palpi 2-jointed) and 

 Triepeolus (maxillary palpi 3-jointed; Plate XCIII) the 

 apex of the marginal cell is obtuse and does not touch the 



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