All the specimens referred to below were collected by Mr. A. F. Posnette in Trinidad, British West Indies, during December 1943 or in January 1944, and were sent by him to the Imperial Institute of Entomology, London, for identification, because some of them, he thought, were of importance in the pollination of cacao flowers. The majority (46) had been found actually in cacao flowers, and all but one of these were referable to the two species, Forcipomyia quasi-ingrami, Macfie (38) and Lasiohelea nana, Macfie (7). It was these two species which Mr. Posnette believed to be “of great economic importance in Trinidad as pollinators of cacao.” The single exceptional specimen, which did not belong to either of these two species, was probably a small example of Lasiohelea stylifer, Lutz. With these insects were sent a few (8) other specimens from moss on the trunk of a cacao tree. They were, however, quite different species, namely, an Atrichopogon, a Stilobezzia, and a Dasyhelea. The following notes may facilitate the ready recognition and further study of these small insects.