ART. 19. AMERICAN BEES OF THE GENUS HALICTUS SANDHOUSE. 9 



23. Disk of propodeum plicatulate; apex polished; meso thorax closely punc- 



tured (Colorado) ruidosensis Cockerell. 



Disk of propodeum with somewhat wrinkled plicae reaching the apex; meso- 

 thorax more sparsely punctured (Colorado) consonus, new species. 



24. Mesothorax shining, sparsely or delicately punctured 25 



Mesothorax opaque, coarsely punctured 26 



25. Front above the antennae very closely punctured; disk of propodeum rugose 



( Colorado ) praepes, new species. 



Front above the antennae without true punctures; apex of disk of propo- 

 deum elevated, tessellate, base weakly plicate (New Mexico). 



astutus, new species. 



26. Tegulae and wings reddened; flagellum ferruginous beneath; mesothorax 



dark blue; pubescence on mesothorax and vertex yellowish (New Mexico). 



abundus, new species. 

 Tegulae and wings not reddened; Ilagellum testaceous beneath 27 



27. Disk of scutellum dull; disk of propodeum dull with irregular rugae (New 



Mexico) tranquillus, new species. 



Disk of propodeum shining; disk of scutellum with two polished spots 28 



28. Mesothorax blue; disk of propodeum plicate (Colorado) pudicus, new species. 



Mesothorax green; disk of propodeum coarsely rugose viridatus Lovell. 



29. Large, 7 mm. long; disk of propodeum rugose 30 



Smaller 32 



30. Tegulae pale testaceous; mesothorax closely punctured (Texas). 



counexus Crawford. 

 Tegulae reddened; mesothoiax very coarsely punctured 31 



31. Wings nailky white; stigma honey color; flagellum yellow-testaceous beneath. 



albipennis Robertson. 

 Wings not so; flagellum testaceous beneath nymphaearum Robertson. 



32. Wings milky white; stigma and nervures honey color; mesothorax very 



coarsely punctured; disk of propodeum plicate (Colorado). 



lactineus, new species. 

 Not so 33 



33. Mesothorax opaque, microscopically tessellate, very closely punctured 34 



Mesothorax shining, sparsely or delicately punctured 37 



34. Head and thorax golden green; disk of propodeum plicate (Virginia). 



callidus, new species. 

 Head and thorax blue or blue-green, not golden 35 



35. Flagellum clear ferruginous; mandibles yellow; propodeum with discontin- 



uous plicae (Virginia) apertus, new species. 



Flagellum testaceous, yellow-testaceous beneath; mandibles dark 36 



36. Tegulae reddish; diskof propodeum plicate; pubescence of abdomen yellowish 



(Virginia) genuinus, new species. 



Tegulae pale testaceous; disk of propodeum rugose; pubescence of abdomen 

 not yellowish versatus, Robertson. 



37. Mesothorax coarsely punctured 38 



Mesothorax delicately punctured 40 



38. Head and thorax brassy green; tip of clypeus and mandibles yellowish 



vTexas) disparilis Crawford. 



Head and thorax blue 39 



39. Disk of propodeum strongly rugose, the rugae not confined to the disk 



(Connecticut) basilicus, new species. 



Disk of propodeum brilliant blue, plicae confined to the disk. 



nevadensis Crawford. 



