The genus Aphylla was proposed by DE SELYS in 1854, when he divided the Gomphoides Complex into the three genera Gomphoides, Aphylla and Cyclophylla (= Phyllocycla; Zoologica 33, Part 2, p. 62, 1948, Cyclophylla preoccupied). However, the differentiating venational characters drawn up by DE SELYS (1854), by DE SELYSHAGEN (1858), and by NEEDHAM (1940) for the genera Aphylla and Phyllocycla are not sharp, as was discussed by CALVERT in his description of Aphylla alia from Kartabo (Zoologica 33, part 2, p. 66-67, 1948). The males of the Surinam dragon flies which have been referred to the genus Aphylla differ from Phyllocycla in that the postero-lateral angles of the tenth abdominal segment are prolonged in a sharp point; the lateral margins of the eighth and ninth abdominal segments are not leaf-like but extremely reduced, to narrow strips; and the distal portion of vein A2 is not strongly convergent with vein A3 but diverges somewhat from it and from vein A1. I believe that these characters place beyond doubt the generic status of the Surinam material in question, which is represented in my collection by adults of three species. Of these species, one is Aphylla producta Selys 1854, already recorded as occurring in Surinam and one is the little known species Aphylla dentata Selys 1859, which has not previously been recorded from this country. The third species is closely allied to the latter and is apparently new; in the present paper it is described under the specific name simulata.