362 EXTERNAL ANATOMY OF INSECTS. 



a Valvula (the Valvule). A corneous piece which 

 covers the instruments of suction above, represent- 

 ing the Labrum in a perfect mouth a . 



b Cultelli (the Knives). The upper pair of the in- 

 struments of suction, which probably make the first 

 incision in the food of the insect; they represent 

 the Mandibida? of the perfect mouth b . 



c Scalpella (the Lancets). A pair of instruments, 

 usually more slender than the Cultelli, which pro- 

 bably enter the veins or sap-vessels, and together 

 with them form a tube for suction c . 



4. Antlia (the Antlia). The oral instrument of Lepi- 



doptera, in which the ordinary Tropin are replaced 

 by a spiral, bipartite, tubular machine for suction, 

 with its appendages d . It includes the Solenaria, 

 and Fistida. 



A Solenaria (the Solenaria). The two lateral subcy- 

 lindrical air-tubes of the Antlia e . 



B Fistula (the Fistula). The intermediate subqua- 

 drangular pipe, formed by the union of the two 

 branches of the Antlia, which conveys the nectar 

 to the Pharynx f . These two branches represent 

 the Maxilla of the perfect mouth. — N. B. M. Sa- 

 vigny discovered the rudiments of the remaining 

 Tropin in this hind of mouth s . 



5. Rostrulum (the Hoslridum). The oral instrument 



; < Plate VII. Fig. 5, G. a'. b Ibid. c'. 



c Ibid. d'. It has not yet been satisfactorily ascertained, whether 

 all the ordinary Trophi are represented in every Dipterous mouth, 

 the number of the lancets seeming in some cases to vary. 



d Plate VI. Fig. 13. e Ibid. a. f Ibid. b. 



p Ibid. Labrum a'; Mandibular c'; Maxillary Palpus h". 



