AbstractThe anatomy of the head is described for three species of syrphid larvae of differing feeding habits and the relation of the structure to the function is shown.The degree of adaptation of both the musculature and the skeletal parts of the cephalopharynx to the type of food which the larva partakes is discussed. The mouthparts are discussed in detail and the probable course by which the complex mandibular lobes of aquatic, filter‐feeding syrphid larvae were evolved, is pointed ou