118 [M^iy. 



more deeply imbricate, or more widely spread, than in fully developed 

 specimens. Flies of Pericoma, Section III, are liable to the same 

 deformity. 



Major Sub-Divisions of Pstchoda. 



A. Wing lanceolate, acuminate at the end of the prsebrachial nervure, and with a 



shallow sinus in the posterior margin from near the anterior pobrachial to 

 near the anal nervure ; neuration, towards the base of the wing, imperfectly 

 explored. Inferior S genital appendages longer than their basis and uni- 

 tenacular, as in Ps. phalmnoides, L. Hair of the dorsum, bristling hair of 

 the wings, and structure of $ antennse unrecorded. No species* described. 

 Syn. Maruina, P. Mill., MS., Trans. Ent. Soc. London for 1895, p. 480, 

 pis. X and xi (part). Type, M. pilosella, idem, loc. cit. (undescribed). 

 Eefer, op. cit., pp. 483—493 (1895) Psychoda, Section O. 



B. Wing ovate-lanceolate, acute at the end of the prsebrachial nervure ; radius 



forked beyond the bifurcation of the pobrachial nervure, or else the pos- 

 terior radius short and free ; bristling hair, in some parts of the wing, 

 extended beyond the shortest line drawn from the end of the subcosta to 

 the end of the anal nervure. Antennse in both sexes liable to individual 

 variation in the number of joints beyond the 13th, and comprised with it 

 in the 11th or terminal, globose or ovoid, compound verticil of hair of the 

 flagellum ; when IS-jointed, the last three joints are minute, subequal to 

 each other, and closely moniliform, without beak or apiculus ; when 14- 

 jointed, the terminal joint, smaller than the 13th, is globular and apiculate ; 

 when 15-jointed, a terminal joint of this last form is preceded by a small 

 globular joint ; 13th joint globular, with hardly any beak ; 12th to 3rd 

 joints bulbose, usually with long subfiliform beaks and globular bulbs, the 

 latter sometimes slightly oval in the baseward joints ; scape short, clad 

 with short scales ; the 2nd joint stout and globular. Hair of the flagellum 

 arranged in eleven verticils of long hair, each involucrate at the base by a 

 whorl of much shorter, appressed, but reversible hair, and constituting, 

 when the beaks of the joints are long, a closely moniliform series ; but 

 short beaks cause the verticils to be wide and cupuliform. Articular 

 appendages present from the 3rd to the 13th joint, hyaline, linear or 

 tsenoid, with seemingly thickened edges, one pair to a joint (or rarely two 

 pairs), inserted close together at the inner base of the verticil of long hair, 

 but widely divergent in elongate, opposed, subspiral curves of about one 

 turn each in length, that bring them near together again towards their 

 extremities. 

 B. Bristling hair present on the subcosta, ending in proximity to the wing- 

 margin. Dorsal hair bristling on all the abdominal segments. Ovi- 

 positor rostrate, horny, exserted, but in repose erect or subreclinate, as 

 in Pericoma and Ulomyia. Beneath the wing-base in the $ , on the 

 nervures bounding the basal cells, also on the margin between the 



* Psychoda nigra. Banks, The Canadian Entomologist, xxvi, 331 (1894), judging by what is 

 mentioned of its wings, may possibly be a Maruina ; but this Section of Psychoda is unknown 

 in Europe. 



