ENALLAGMA OPTIMOLOCUS, A NEW SPECIES OF DAMSELFLY FROM MONTANA (ODONATA, COENAGRIONIDAE)

Enallagma optimolocus n. sp. is described and diagnosed from streams i n western Montana. Garrison's 1984 key is modified to distinguish this species from the related E. carunculatum Morse and E. civile (Hagen). The competing aspects of two views of these specimens, i.e. full spec ies or hybrid individuals, is discussed. The occurrence of E. caruncul atum and E. anna Williamson at the collecting sites is noted. The abse nce of E. civile from the areas surrounding the range of E. optimolocu s is noted, with Roemhild's 1975 (and Garrison's 1984) record of E. ci vile for Flathead Co., Montana, corrected to E. carunclulatum. Illustr ations of diagnostic features for the species are given.