ADULT. The adults obtained from the breeding cage, (there are no others in our collection), are easily distinguished from _prodenialis_ Wlk., by the much stronger dentations of the outer line of the primaries. Prof. Smith kindly sent a specimen of _prodenialis_ taken at Ocean Grove, New Jersey, for comparison. The row of marginal black spots on the primaries which Hulst (Tran. Am. Ent. Soc., v. xvii, p. 172) mentions as distinctive of dentata is as pronounced in Prof. Smith’s specimen of _prodenialis_ as in our _dentata_. The much lighter color of the primaries, head and thorax in dentata as mentioned by Hulst is characteristic. An interesting feature in the venation of the hind wings in our bred specimens of _dentata_ is the considerable coalescence of the sub-costal and costal veins. Vein five is wanting, as mentioned by Hulst. In addition, there is further departure from a normal venation, in that vein seven after rising with six from its stem, (Hulst says: “Six short stemmed with seven”), coalesces for a short distance with eight and then runs free to the margin. Behind the forking of seven and six the stem (remnant of sub-costal) unites with the costal, and its basal portion is wholly merged with the forward vein. This partial disappearance of the sub-costal seems to be shared by _prodenialis_ and is probably characteristic of the genus. Prof. Smith, as recorded in the Canadian Naturalist, v. viii, p. 242, (1891), bred several specimens of _Volucella fasciata_, a Syrphid fly, from the same prickly pear leaves in which the _Melitera_ larvae were living. It is interesting to note that pupariae and later, adults of _Volucella fasciata_ and _Copestylum marginatum_, a closely allied Syrphid, were noted in the Opuntia leaves from which _M. dentata_ was bred. (See note by Dr. Williston, Entomological News, v. ii, p. 165, 1891). Diptera Brasiliana. BY S. W. WILLISTON. PART II.[11] [11] See Trans. Amer. Entom. Soc. xv, p. 243, for Part I. CONOPS. 1. First basal cell hyaline 2 First basal cell clouded throughout 6 2. Third joint of the antennae as long as the first two together; small species _parvus_, n. sp. Third joint of the antennae but little if any longer than the second joint 3 3. First posterior cell hyaline 4 First posterior cell more or less clouded 5 4. Cheeks yellow _angustifrons_, n. sp. Cheeks black _ornatus_, n. sp. 5. Face black in ground-color _argentifacies_, n. sp. Face yellow, large species _grandis_, n. sp. 6. Red species; front red _rufus_, n. sp. Black species; front black 7