NEW BEES OF THE GENUS ISCHNOMELISSA ENGEL, WITH A KEY TO THE SPECIES (HYMENOPTERA, HALICTIDAE, AUGOCHLORINI)

Five new species of the rare neotropical bee genus Ischnomelissa Engel , Ischnomelissa riana, I. cyanea, I. lescheni, I. ecuadoriana and I. o ctogesima are described and figured. I. cyanea, like the type species I. zonata Engel, has a narrow malar space. The other four species have elongated malar spaces very similar to the genus Chlerogella Michener . Because of the addition of five more species to a previously monotyp ic genus, a new generic diagnosis is given along with a key to all kno wn species. The genus was previously known only from Colombia, but has now been found in Ecuador.