238 DIPTERA. 



very small size, and are black or yellow, more or less striped with 

 the opposite colour ; their wings also are often black or yellow. 

 The two principal genera are Chlorops, Meig., and Oscinis, Latr., 

 the larvae of which live in the stems of various grasses, and are 

 sometimes extremely injurious to corn. 



SUB-FAMILY VII. Drosophilince. 



Head semicircular; eyes not prominent; forehead broad; 

 mouth and vertex bristly ; third joint of antennae rather long ; 

 terminal bristle generally pectinated or pubescent ; abdomen short 

 and broad ; wings long, and generally broad ; legs short and stout ; 

 larvae feeding on decaying vegetable matter. 



These are small dull-coloured flies, the larvae of which feed on 

 fungi, rotten fruit, and similar substances. Drosophila Cellaris, 

 Linn., is a reddish species, about the tenth of an inch in length ; 

 its larva is almost omnivorous, being often met with in stale beer 

 and wine ; and it has even been found in a pickle-jar, feeding on 

 pickled cauliflower. 1 



SUB-FAMILY VIII. Agromyzince. 



Head semicircular ; forehead broad ; vertex and mouth gener- 

 ally bristly ; antennae short, third joint rounded ; bristle naked or 

 pubescent ; abdomen oval, convex ; wings longer than the abdo- 

 men ; legs short. 



An extensive family ; but the majority of the species belong to 

 the two genera Agromyza and Phytomyza ; their larvae mine in the 

 leaves of plants like those of the Tinece. One of the commonest 

 species is Phylomyza Ilicis, Kali, the larva of which forms large 

 brown blotches on the leaves of the holly. The perfect insect is 

 a very small black fly, scarcely one-twelfth of an inch in length. 



FAMILY XXXVL PAorido. 



Head small, compressed, not broader than the thorax ; fore- 

 head broad in both sexes ; eyes large ; ocelli present ; antennae 

 always placed close to the mouth, third joint rounded, with a 

 naked or pubescent bristle at the tip or on the upper surface ; 

 abdomen short, broad in front, and narrowed behind ; ovipositor 

 of the female prominent ; coxae long ; femora (especially the hind 

 femora) widened and compressed ; hind tibiae often curved, and 

 hind tarsi very long ; wings large ; larvae feeding on dead or living 



1 Proceedings of the Entomological Society of London, 1877, p. xv. 



