,,_Q Contribution towards the history of a new form of larvae cf Psychodidae (Diptera), from Brazil. 



Three kinds of larvae are easily distinguished : two of them have the ap- 

 pearance of woodlice {onisciform, O, S.) ; their abdominal segments bear on each 

 side straight thorns, the length of vvhich is much less than half a breadth of the 

 abdomen; in one of the species, Maruina pilosella (figs. 2, 3, 4) they are simple, 

 in the other {M. spinosa) they have from four to six, seldom seven, branches. 

 The third species, M. iirsida, which, in many respects. is very aberrant (fig. i), bears 

 on each of the abdominal segments three pairs of very long and very much curved 

 bristles, of vi^hich one pair is inserted very near the lateral margin of the segment, 

 and two pairs, close by each other, are placed on one of the three dorsal plates 

 of the segment. The abdominal segments of the two other species likewise show 

 three dorsal plates on each abdominal segment, and laterally these segments are 

 very conspicuously divided into three lobes (fig. 4). A character that the three 

 species of larvse have in common is the head, which is much narrowed in front, 

 and has on its upper side two small eyes, placed near the middle of the lateral 

 margin ; a little inside and in the front are two short antennae, without any joints, 

 and still more inside of these are two minute punctured Spots (figs. i and 3). 



In Mamma pilosella and spinosa the last abdominal segment projects but 

 little beyond the penultimate segment, which rounds off the end of the abdomen 

 (fig. 2); in Maruina ursiila this last segment takes the shape of an elongate, 

 bottle-shaped projection, at the end of which the two principal branches of the 

 trachese meet. These openings are surrounded by a Coronet of delicate, short 

 hairs, between which a globule of air of considerable size is sometimes visible 

 (fig. I /). The anal opening in this species lies on the ventral side a little before 

 the openings of the air-tubes. The fig. i shows on each side a pair of protruding 

 tracheal branchiae. Fig. 5 shows, on a larger scale, the tracheal branchise of the 

 larva of M. pilosella, six in number. 



The ventral side of the larvse of the three species is provided with eight 

 suctorial discs, the last of which is placed on the penultimate segment (fig. 2). 

 As to their structure I must refer to the figures (figs. 6 and 7), as it is from 

 these only that I could describe them now. The figure of the rather flat, not, 

 as in Curupira, very convex pupa (fig. 8), requires no further explanation; I 

 would only call attention to the wicker-basket-like covering of the claviform 

 respiratory tubes (fig. 9). 



The fly strikes one at once by its singular appearance in repose. Examined 

 from the ventral side, for instance, when resting on the side of the tumbler, the 

 eyes seem to stare at one from the middle of the body, because the head is so 

 much bent under the body, pointing backwards; from above the head cannot be 

 Seen at all. The wings, beset with long hair, look like two narrow stripes, 

 directed backwards and a little outwards, and are raised considerably above the 

 body; the peculiar twist they have is represented in fig. 13. 



The venation of the wings (fig. 12) resembles that of Psychoda; they end 

 in a point in Maruina pilosella (fig. 12a); the end is more obtuse in M. spinosa 

 (fig. 14); I am not quite sure, however, whether this character belongs to the 

 species, or is merely sexual. 



The antennae are represented as 1 6-jointed in all my old drawings ; the third 

 and the following joints show verticils of hairs near the base. The palpi are 

 4-jointed, the two last joints are beset with elongated scales, about 0,02 — 0.05 long. 



