June, 1897.] 121 



base and beak of each joint glabrous ; the verticils at first cupuliforui, 

 but increasing and afterwards diminishing in amplitude jjari passu 

 with the length of the beaks, and, therefore, widest and shallowest 

 from the 8th to the 12th joints. Articular appendages of the flagel- 

 lum present in the form of concave digitate fascicles of capillary 

 filaments, difficult to distinguish from an interior verticil of soft 

 capillary scales, unless the hair be partly removed. 



Bristling hair of the wing wholly interior to the shortest line 

 drawn from the end of the subcosta to the end of the anal nervure ; 

 wanting on the subcosta, proebrachial and anal nervures in both sexes, 

 and in the ,^ of one species wanting also on the axillar, but when 

 present on this last nervure extended farther in the ? than in the (J ; 

 its endings from the anterior radius to the postical nervure lie in an 

 obtuse salient curve or angulate line with one another, having the 

 angle or the summit of the curve on the cubitus. 



Whenever generical dismemberment of the current genera Peri- 

 coma and Psychoda comes to be executed, it would seem from their 

 bibliography that Pericoma should be restricted to species of the 

 present Section, and Psj/choda to species syntypical with Ps. 

 phalcenoides, L. A rather different employment of these names was 

 proposed by Mr. N. Banks, in " The Canadian Entomologist," xxvi, 

 329 (1894), and Westwood previously, in his " Introduction to the 

 Modern Classification of Insects," cited in the General Synopsis quite 

 a different insect as the t3^pe of Psijclwda ; but the disposal of these 

 names seems to be governed by the publications of Curtis and Haliday.* 



* Curtis, in British Entoroology, xvi, 745 (1839), to illustrate the genus Psychoda of older 

 authors, which was co-extensive with Psychodidce, published a whole figure with details of Ps. 

 sexpunctata. Curt., and some details of one or possibly two other larger species of the Family, 

 notably T, thorax and head in lateral profile (omitting parts of appendages) of Ps. awiculata, 

 Hal., MS., exhibiting a pair of persistent prothoracic air-nipples, and fig. 9, a wing of (one would 

 suppose) the same species. In the accompanying text Ps. sexpunctata is desci-ibed, and on the 

 next page follows an abstract synopsis of the British species of Ps7/cho(la by Haliday, in which 

 are scheduled four genera, lettered A to D, and ten species numbered consecutively, irrespective 

 of the genera. Of these, A, fiaccopteryx (= Ulnmyia.J is an offset of the ancient Psychoda ; B is 

 the residuum of Psychoda ; C, Trichomyia, and D, Sycorax, are new forms. The list of species 

 under B, P.tychoda is headed by 2, anriculata, Hal., MS. ; and among the remainder, 3, ocellaris, 

 Lat., Meig , 6, nubila, Meig., 6, sexpunctata, Curt., and 8, phalanoides, L., D.G. (with 8b"3 nervosa^ 

 Schr. , the last), may be cited to show the plan of classification. 



Haliday subsequently, in Walker's Insecta Britannica, Diptera, vol. iii (1856), established two 

 genera in place of the B, Psychoda, of 1839, and making them precede Ulomyia, re-adju.sted the 

 sequence of the species accordingly ; the plates are by Westwood. The first genus, Psychodw 

 'restricted), comprised two .species, viz.: Ps. phalcenoides, h., and sexpunctata, Curt., mention 

 being made of a third, humeralis, Meigen ; the second, Pertcoma, Hal., MS., eleven species, com- 

 mencing with acute-winged and ending with broad and obtuse-winged species, some of those 

 with acute wings being ranked here with hesitation (instead of in P.tychoda), pending fuller 

 investigation. It will sufiice to cite in this place (2) P. soleata, Hal., MS., p. 257; (4) ocellaris, 

 Meig., and (5) canescens (=notabilis, Etn.), p. 258 ; [S) palastTis, Meig. iquotiug as synonymous 

 auricv.lata [Hal., MS.], Curt., B. E., 74.5), p. 259; (9) nubila, Meig. : (10) fusca, Macq., and (11) 

 calceata, Meig., p. 260. The sjmonymy attributed to the species of Pericoma, concerned in Curtis's 

 figures is misleading ; auriculata, Hal. , MS. , could not have been the palustris of Walker's volurne, 

 because this .species has no prothoracic air-nipples in the adult ; nor can the wing in question 

 belong to the P. canescens fnotabilis. Etn.) of the same work, as is alleged at p. 254, being quite 

 of a different foim to the wing of that species. It concerns, in fact, a species of the present 5th. 

 Section of Pericoma, and there is no reason why 't;>oth the figure of the wing and that of the head 

 and thorax might not have been drawn from one and the same individual fly. The main point, 

 however, is that at p. 254 reference is made to Curtis's dissections of a Pericmaa in B, E., 745, 



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