Introduction to Animal Morphology. 407 



Order 10. Aphaniptera (AYr^r) : Fleas laterally com- 

 pressed, wingless, or with scale-like rudiments, with simple 

 or no eyes, short antenna?, lying in a groove; labrum none ; 

 mandibles long, slender, saw-like, having between them the 

 needle-like epipharynx. Maxillae short, broad, with long, 

 four-jointed palps ; labium cleft, palp-like, often jointed ; 

 thoracic segments homonomous, discrete; hind legs saltatory ; 

 larva? white, hairy, footless, worm-like. Blood-sucking para- 



s, closely related toDiptera, forming one family Pulicidoc. 

 The labium is distinct (Pulex), or rudimental (Sarcopsylla, 

 the chigoe ; its females burrow in the skin of exposed parts 

 in the West Indies). 



Order u. Diptera metabolic, with suctorial mouths, two 

 transparent, mesothoracic wings, with radiate costoe, and nidi- 

 mental, often irregular, mesothoracic wings, modified into scale- 

 like or pin-like halteres, or balancers ; eyes two, very large ; 

 ocelli three, vertical ; neck slender. The mouth is a proboscis, 

 of which the labrum and labium each make make half-till- 

 the maxilla? (scalpclla\ mandibles (cultelli), are bristle-like, 

 or knife-like, accessory organs, and the former always bear 

 palps. There is also in the last a median sharp epi- 

 pharynx (glossarium). The labial palps are absent, but 

 the maxillary palps often appear 

 as labial (Stratiomyidae, Muscidae). 

 The antenna) are single, pecti- 

 nate, or short, three-jointed, with 

 a bristle (arista) at the tip, which 

 may be naked (arista nuda), or 

 hair-clad (pilosa\ or terminal (af>i- 

 calis), or dorsal (dorsa/is). The n.-im.fwir 



N ' tenor basal < .-II ; 2, binder marginal 



prothorax fused with the strong cell; 3, third basal cell ; : 



T-1 



mesothorax. Fhe wing is divid< 



uto celluli(Fig. 4 s), E 



two lobes, an ', 

 alula and a squarn.i, tin- latt- 



ends in ; 

 . with one or mop- intervening cushion* Of Jtulvilli, 



A nli cftcn a 







