ORTALIDiE — SYSTEMATIC DISTRIBUTION. 39 



do not show any important difference from Platy stoma ; still it 

 is worthy of notice that the under side of the front femora is beset 

 with a row of little black bristles, which in the larger species 

 assume the shape of slender spines. The coloring of the body 

 is generally ochre, or ferruginous-yellow, usually with black 

 longitudinal stripes on the thorax ; the picture of the wings con- 

 sists of numerous black spots, which often coalesce into cross- 

 bands. In Scholastes ductus Guer., and the species from 

 Australia allied to it, the first half of the arista is feathery, the 

 second bare, and on the thoracic dorsum there are two rather 

 distant rows of short, but strong bristles. The African Scho- 

 lastes, as the type of which I consider S. nepticula Lw., from 

 Guinea, have the whole arista bare and no trace of rows of 

 bristles on the thorax. These characters may afford a ground 

 for dividing Scholastes in two genera, in which case the present 

 generic name would have to remain with the genus containing 

 S. cinctus Guer. 



Another genus, closely related to Platy stoma, containing, as it 

 seems, exclusively Australian species, is the genus Lamprogas- 

 ter Macq., with which Ghromatomyia Walk, is synonymous. 

 The structure of the thorax, of the abdomen, and of the feet, as 

 well as the venation, are very much in agreement with Platy - 

 stoma. The tegulae are large, larger than those of most Platy- 

 stomae. The structure and the arrangement of the bristles of 

 the front are likewise similar to those of Platy stoma ; only the 

 third antennal joint is much longer; not only are the antennal 

 foveae also longer, but deeper and more sharply defined, on their 

 inside especially ; the clypeus is of the same breadth as in Pla- 

 tystoma, but not projecting; the palpi usually towards their end 

 are not as broad as in Platystoma, and the occiput is less swollen ; 

 the scutellum is strikingly swollen and provided with six bristles. 

 The abdomen of all the species is of a brilliant metallic color, 

 which the scutellum and the middle of the thorax often share with 

 it ; on the latter, however, the metallic color is generally con- 

 cealed by the presence of pollinose longitudinal stripes, and of 

 an appressed pubescence of a light color. Otherwise, the color- 

 ing of the thorax generally is brown or chestnut-red, which color, 

 in many specimens, also extends over the scutellum ; the color- 

 ing of the wings consists of a few black spots. All the known 

 species of Lamprogaster have unarmed femora and a bare arista ; 



