ENTOMOLOGY 



insects in general, the salivary glands open at the base of the hypo- 

 pharynx. In the most generalized insects, Thysanura and Collembola, 

 the hypopharynx is a compound organ, consisting of a median ventral 

 lobe, or lingua, and two dorsolateral lobes, termed superlingua by the 



FIG. 48. Maxilla of Harpalus caliginosus, 

 ventral aspect, c, cardo; g, galea; /, lacinia; 

 p, palpus; pf, palpifer; s, stipes; sg, subgalea. 



PIG. 49. Labium of Harpalus caliginosus, 

 ventral aspect, g, united glossae, termed 

 the glossa; m, mentum; p. palpus; pg, palpi- 

 ger; pr, paraglossa; sm, submentum. The 

 median portion of the labium beyond the 

 mentum (excepting the palpi) is termed the 

 ligula. 



author. Superlinguae occur in other mandibulate orders just mentioned, 

 but have not yet been recognized in the most specialized orders of 

 insects. 



PIG. 50. Hypopharynx of Hemimerus 

 talpoides. I, lingua; s, superlingua. After 

 HANSEN. 



FIG. 51 . Hypopharynx of an ephemerid, 

 Heptagenia. I, lingua; si, si, superlinguae. 

 After VAYSSIERE. 



Suctorial Types. The mandibulate type of mouth parts is the 

 primitive type, from which the suctorial types have been derived. 

 Though the latter have evolved in several directions, they may all 

 be homologized with the former. 



