ENTOMOLOGY

146 SANITARY ENTOMOLOGYof minute granules, ending each side in a larger granulate tubercle; thereare no tubercles outlining the stigmal field; the stigmal plates are subtriangular,about one and one-half times their diameter apart, black,and each with three pale areas containing an S-shaped slit (fig. 24).These slits are never near each other like in the house fly, and there is noapparent button.This latva commonly breeds in manure of various kinds, but also inFIG. !i!S.-Larva of Stomo"'!!11 calcitra1lll: enlarged sketch of thoracic spiracles. (Greene.)decaying matter, and is not often passed by people, but there is onerecord. Horse manure, cow manure, and wann, decaying vegetation, likeold straw and grass heaps, are common breeding places.FIG. !i!4.-Larva of StomO"'!!1I calcitranll: enlarged sketch of right stigmal plate. Theseplates are one and one-half times their breadth apart. (Greene.)Muscina stabulans FallenHead of larva (fig. 25) divided into two parts from above, no distinctpapilla; two great hooks close together; anterior spiracles withabout six lobes (fig. 25b). The surface of the segments is mostly smooth.Beginning with the fifth segment, on the under side, there is a basal,transverse, swollen area, furnished on the crest with rows of teeth; eachof these areas is divided on the median line. On the next to the lastsegment there is a similar area at the tip, but not divided. The segmentsbelow also show a transverse line before the middle. The lastsegment has the anal basal area with spines, but not very prominent,,and bears a median and three lateral tu~rcles with spines. The tubercles