i:v A. I.. TO.NNom. 69 



DIXA NICHOLSOXI, Tonn. 



The full-grown larva is 8 mm. long, its colour grey with 

 brown diffused markings on the dorsum. 



Head black with ferruginous parts chiefly on the sides. 

 Antennae with the usual short triangular spines, without 

 hairs, carrying only one small external bristle inserted about 

 one-third before the extremity. Mandibles and maxillse of 

 the usual type, these last conical and as long as the maxillary 

 palpi. Mentum bluntly conical without any distinct inden- 

 tation. Labrum with two rather well developed tufts of 

 hairs. 



Anterior edge of prothoracic sternite with a row of very 

 long bristles reaching beyond the head; four of them are dis- 

 posed in a tuft, and are, with the others, in the following 

 order: 1.1.1.1.4.1.-1.4.1.1.1.1. The two pairs of pseudopods of 

 the two first abdsminal segments are equally developed. The 

 armature of spines on the sternum of abdominal seguients 

 5-G ai'e composed of two groups of two juxtaposed rows of 

 spines, containing each 7 spines pointing backwards, the 

 spines of the upper row being much stronger than those of 

 the inferior row; on the 7th segment the groups are composed 

 only of rows of o spines; the two groups of rows are separated 

 by a .small longitudinal chitinous band. The basal sternal 

 plate (if the caudal appendage has two groups of three rather 

 long bristles reaching beyond the end of the caudal appen- 

 dage, which is black, and carries six long bristles at its ex- 

 tremity. 



The structure of the spiracular plates, as in figure 7B ; 

 the spiracles themselves elongated; between them there is a 

 chitinous armature in shape of a V surmounted on each side 

 with three tufts of small curved hairs. The lateral plates 

 are not connected at their base by a chitinous structure; 

 their comb, situated on the middle of their inferior side 

 (the lateral side of the body), is formed by a regular row 

 of moderately developed spines, the last of which is stronger 

 than the others. 



DIXA TASMANIENSIS, Tonn. 

 Length of full-grown larva 6 mm.; it is very similar to 

 the larva; of the preceding species; its colouration is the 

 same, and its whole body is also covered with a microscopical 

 but very dense pubescence. Head mostly ferruginous, blackish 

 above and with a black posterior edge. Antenna^ with the 

 usual short spines, and besides the external small bristle, 



