128 PROCEEDINGS OF THE NATIONAL MUSEUM. 



costal wing vein spinose, as well as the arista plumose or sub- 

 plumose. The Chloropidae have the frons bare or at least without 

 bristles; the basal cells of wings absent and generally a peculiar 

 curve at the middle of penultimate section of fifth vein; the pleurae 

 are bare. 



HABITS OF THE SPECIES. 



Most of the species in the larval stage in Agromj'^zinse are phytopha- 

 gus, making mines in leaves and stems of plants, and a few species 

 of the genus Agromyza make galls on twigs of trees. The Phyto- 

 myzinse are, so far as is known, miners in leaves. The larvae of 

 OchthipMla have been found in galls of Triticum repens. The species 

 of the genus Leucopis, so far as they are known, feed upon aphides and 

 scale insects. The single American species of the genus Cerodontha 

 mines the stems of wheat and does considerable damage. The 

 peculiar genus CryptoclisetuTn is predaceous in the larval state on 

 coccids. 



The perfect insects are generally found on flowers, some of them 

 being especially abundant on the flowers of umbelliferous plants in 

 late summer. 



TERMINOLOGY. 



Center stripe. — An usually opaque stripe inclosed between the 

 orbits and generally differentiated from them by being less shining 

 and rather more depressed. Bare in Agromyzinse; in the Milichinse 

 and in some of the Ochthiphilinse, with short bristles. 



Frons. — This term I have used to designate the space bounded by 

 the eyes laterally, the frontal lunule anteriorly, and the vertex pos- 

 teriorly. It includes the orbits, center stripe, and ocellar triangle. 



Lunule. — A small lunulate portion in front of frons and immedi- 

 ately over antennae. 



Occiput. — That part of head behind eye, viewed from the side. 



Ocellar region. — This term I have used instead of the "ocellar 

 spot" used by some writers. It is the slightly raised triangular por- 

 tion occupied by the ocelli. 



Ocellar tnangle. — This is a large subtriangular, generally glossj^, 

 portion with its base at vertex and its apex intersecting the center 

 stripe, on which are situated the ocellar region and ocelli. In most of 

 the species in Agromyza and some other genera it is not distinguish- 

 able, but in some of the Milichinse it is much more evident, approach- 

 ing more nearly to the Chloropidae, in which family it is very distinct. 



Orbit. — The narrow, more or less shining lateral stripe upon which 

 are situated the orhital bristles. 



Post-vertical bristles. — The pan- situated immediatel}^ behind the 

 ocelli on the vertex. 



Vibrissa. — The usually differentiated bristle at anterior margin of 

 cheek on a level with upper mouth margin. 



