183] HEAD OF DIPTERA— PETERSON 13 



Diopsidae.— Sphyracephala bieornis (Fig. 52, 94, 190, 293, 338, 450, 



451, and 585). 

 Ephydridae.— Ochthera mantis (Fig. 56, 101, 187, 237, 297, 336, 



444, 445, 483, and 574-577), Paralimna appendiculata, and 



Parydra bituberculata. 

 Oscinidae.— Chloropisca glabra (Fig. 51, 132, 189, 306, 345, 430, 431, 



555, and 556), Siphonella abdominalis, and Hippelates flavipes. 

 Drosophilidae.— Drosophila ampelophila (Fig. 45, 125, 172, 238, 291, 



343,454,455, 563, and 564). 

 Geomyzidae.— Chyromya concolor (Fig. 50, 122, 179, 233, 299, 333, 



411, 412, 568, and 569). 

 Agromyzidae.— Desmometopa latipes (Fig. 47, 129, 185, 228, 303, 



330, 404,405, 578, and 579). 



Suborder Eproboseidea 



Hippoboseidae.— Olfersia ardeae (Fig. 57, 139, 198, 249, 358, 488, 

 and 606), and Melophagus ovinus. 



Obthoptera 



Periplaneta orientalis (Fig. 514). 

 Melanoplus differentialis (Fig. 515). 

 Gryllus pennsylvanicus (Fig. 516). 



Hypothetical and typical figures (Fig. 1, 73, 140, 141, 199h, 256h, 

 257, 362, 363, and 493). 



FIXED PARTS OF THE HEAD 



A hypothetical head-capsule of Diptera (Fig. 1) has a dorso- ventral 

 extension. The epicranial suture (e. s) is present on the meson, and 

 extends from the occipital foramen (o. f ) to a point on the cephalic 

 aspect ventrad of the antennae. At this point it bifurcates and the two 

 arms continue to the invaginations of the anterior arras of tlie tentorium 

 (i. a), which are situated at the dorso-lateral angles of the clypeus (c). 

 The three unpaired sclerites included within, or ventrad of, the fork of 

 the epicranial suture are the front (fr), clypeus (c), and labrum (1). 

 The fronto-clypeal suture is represented by a dotted line in the figure. 

 The vertex (v) includes all of the dorsal and cephalic aspects of the 

 epicranium except the front (fr), while the genae (ge) are the regions 

 of the vertex ventrad and mesad of the compound eyes. Two large 

 compound eyes (c. e) cover the lateral portions of the cephalic aspect. 

 Three ocelli (oc) are situated on the vertex. The occiput (oec) and 

 postgenae (po) constitute the caudal aspect of the head-capsule. 



