Microdon. 579 



scopically hairy. Epistoma evenly arched, without central knob or 

 protruding mouth edge, parallel with the eye-margin and thus curving 

 evenly inwards below; it is not descending; the colour of epistoma is 

 æneous, and it has longish, dense hairs. Jowls of moderate size, not 

 descending; they have a pit in front at the lower eye-margin. The 

 oral aperture is small and round. Proboscis short, and the palpi very 

 short, but I have othervvise not examined the mouth parts. Thorax 

 is quadrate; scutellum has two larger or smaller, pointed processes 

 or spines at the apical margin ; it is æneous or brownish red, v^ithout 

 any marginal fringe below. Metapleura with short, dense hairs. No 

 thoracai or scutellar bristles present. Abdomen broad near the base, 

 broader than thorax, somewhat narrowed behind; first segment small 

 and rather narrow; in the male there are four not transformed seg- 

 ments, the fourth very long, nearly as long as the three basal together, 

 but on the ventral side it is much shorter. Genitalia somewhat large, 

 of usual construction. In the female abdomen has five visible segments, 

 the two last somewhat long; the fourth dorsal segment has the hind 

 margin roundly incised in the whole breadth; the following segments 

 after the fifth are hidden, the last has at the end two small lamellæ. 

 Legs somewhat short and strong, tarsi broad and flattened, hind 

 metatarsi somewhat swollen; the femora have a curious offset near 

 the base on the anterior side, this part is all covered with short hairs 

 and represents the usual scabrous patch. The femora are rather 

 short-haired, the tibiæ densely haired with not short hairs; a solitary 

 bristle above the trochanters present. Glaws and pulvilli well developed; 

 empodium relatively large, styliform but compressed, hairy. Wings 

 rather short; the radial vein curved upwards from the base of the 

 cubital vein; the cubital vein with a curious veinlet stretching down 

 in the middle of the first posterior cell, half way or more through it; 

 medial cross-vein placed near the base of the discai cell; the upper 

 marginal cross-vein recurrent, the lower about perpendicular; there is 

 no stigma but a distinct stigmatical cross-vein ; the basal part of the 

 radial vein with short, almost not visible bristles. Squamulæ not 

 large, the thoracal squamula with moderately long, branched hairs, 

 alar squamula with simple hairs, nearly even as long as those on the 

 thoracai squamula. Plumula short, with simple hairs. 



The metamorphosis is rather well known ; the larvæ are some- 

 what similar to small slugs, and they have given rise to a whole 

 literature. When first detected the larva was described as a new 

 genus {Parmula) of land Mollusca by v. Heyden (Isis 1823, 1247) and 

 in 1824 likewise as a new genus of land Mollusca {Scutelligera) by 

 V. Spix (Abhandl. d. bayr. Akad. d. Wissensch. IX), and in the following 



37* 



