154 THE INTEGUMENTAL SKELETON OF THE IMAGO. 



maxillae is sufficiently obvious in Tabanus, where they are 

 supported by a massive hollow cardo, or basal joint, and also 

 in the curious sand-fly (Simula reptans), one of the Biblionidse, 

 the female of which is a ferocious blood-sucker. In these 

 insects the palpiger bears a broad trenchant blade, and the 

 lacina is strong and serrated as in the Fleas. 



Synonymy of the mouth organs of the Diptera; the following are the most 

 important : 



Rostrum, Fab. Kopfkegel, Kraepelin. Russelstiel, Graber. 



Labrum, Clypeus, Fabricius. Properly prelabrum, Mihi. Operculum, 



Mihi [62]. Labrum of authors generally. Labrum-epipharynx, 



Menzbier. 



Fulcrum, Menzbier and Dimmock. Pharynx, Meinert. 

 Palpiger, Mihi. Mandible. Superior lancet. 

 Lacina, Mihi. Inferior lancet. Maxilla. 

 Palpus, Maxillary palpus, Kirby and Spence, Gervais. Labial palpi in 



some Diptera. Savigny. 

 Ligula, Hypopharynx, Savigny. 



Pseudolabium, Mihi. Labium, Savigny, and generally. 

 Oral Disc, Mihi. Labial palpi, Burmeister, Erichson and Kraepelin. 

 The other parts mentioned in the above description have not hitherto 

 received names except where the synonymy has been already indicated. 



4. THE THORACIC EXO-SKELETON. 

 a. General Morphology. 



The Thoracic Exo-skeleton exhibits great uniformity, even in the 

 most dissimilar insects. It always consists of three highly 

 modified somites, which Audouin [38] named the pro-, meso-, 



Bibliography : 



72. JURINE, L., 'Observations sur les ailes des Hymenopteres.' Me'in. 



Acad. Sc., Turin, xxiv., 1820. 4to. 



73. CHABRIER, J., ' Essai sur le vol des Insectes.' Me'm. du Museum, 

 torn. vi. to viii., 1820-22. Paris, 4to. 



