Diceratobasis melanogaster spec. nov., a new damselfly from the Dominican Republic (Zygoptera: Coenagrionidae), with taxonomic and distributional notes on the Odonata of Hispaniola and Puerto Rico

D. melanogaster sp. n., Ischnura capreola, Anax amazili, Tholymis citrina, Tramea binotata are newly recorded for Hispaniola; Coryphaeschna viriditas, Miathyria simplex, Tauriphila australis, Tholymis citrina, Tramea binotata, and T. calverti are new for Puerto Rico. — D. melanogaster sp. n. (Dom. Rep.; La Vega Prov., roadside cuts along Constanza Rd, 15 km E of Autopista Duarte, elev. 1000 m, 8 Aug. 1983, R.W. Garrison) differs from D. macrogaster in lacking horns on the basal segment of the penis and in having IR2 recessed to the third or fourth crossvein of the second series just proximal to the pterostigma in both wings (recessed to first or second in D. macrogaster). The generic status of Diceratobasis is discussed, and a key is presented for most neotropical coenagrionids which lack postocular spots. — Extended discussions are given on inter-island variability of Telebasis dominicana and T. vulnerata, as well as the validity of the subspecies Cannaphila insularis funerea.