Xanthandrus. 235 



siderably longer than broad; arista apparently bare. Epistoma entirely 

 black; it is a little retreating downwards, the central knob moderately 

 prominent. Jovvls slightly descending, Scutellum æneous. Abdomen 

 large, flat, somewhat elliptic, at its broadest part fuUy as broad as 

 thorax; it has extensive orange markings, largest in the male. The 

 number of abdominal segments as in Melanostoma, the fifth dorsal 

 segment in the male llkewise small and unsymmetrical, and the fifth 

 ventral segment quite small and hidden. Legs simple; all tarsi a 

 little flattened in both sexes. 



As said the genus is very near to Melanostoma and chiefly separ- 

 ated by the shape of abdomen, yet it may be convenient to keep it. 



The developmental stages are well known. The larva was first 

 mentioned by Peragallo (Ins. nuis. Agricult. II, 1885, 140, fig. 8); it was 

 found feeding on the larva of Prays citri. Next, Ghapman mentions 

 and describes it (Entom. Month. Mag. XLI, 1905, 151 and XLII, 1906, 14); 

 he found the larva at Hyéres in the south of France on Asphodelus 

 microcarpus, where it fed on a Tor^nx-larva {Hastula hyerana), and 

 on Sicily feeding on larvæ of Åcrolita consequana on Euphorbia, and 

 again at Lautaret on larvæ of Ancylis derasana? on Rhamnus. The 

 larva and pupa are further described and figured by Silvestri (Boll. 

 del Laborat, di Zool. Gen. et Agrar, in Portici, II, 1908, 112), who 

 found them in Italy on Olive trees feeding on larvæ of Prays oleellus. 

 I have myself examined two pupæ, one taken as larva on Populus 

 between Aphides on ^^/s, it pupated and developed at the end of the 

 month, and one found sitting on a Betula on 'Vio, developing on ^^/lo. 

 — According to the descriptions the larva is green with lateral markings 

 of yellow and central of brown, the colour being due to translucence, 

 as the skin seems to be almost colourless; the larva is otherwise 

 similar to many Syrphus-\aryæ ; the length is about 12 mm. The pupa 

 is of a somewhat curious shape, high and somewhat globular in the 

 anterior two thirds, behind falling suddenly off to a flattened posterior 

 part which at the end has a short, longitudinally divided posterior 

 spiracular process. The pupa is nearly flat belovv; it is very slightly 

 transversely corrugated and I could detect no spinules; the posterior 

 part is a little keel-shaped along the middle, and at the margin this 

 part is expanded into a relatively broad, delicate brim. The empty 

 puparium is brownish yellow above, with indistinct darker lateral 

 stripes and a broad middle stripe; below it is white; it has a length 

 of about 8 mm, and the thick anterior part is 4 mm in diameter. 

 Ghapman also describes the pupa and mentions, that it may vary 

 much in colouring, from pale green without markings or with three 

 pairs of black dots, to being darker, and there may be brownish or 



