EXTERNAL ANATOMY OF INSECTS. 449 



garded as having no maxillary palpi, since they exhibit 

 no organ that is distinctly palpiform. It seems to me 

 that the upper lobe of their maxilla, which articulates 

 with the stalk in the same manner as a feeler, may 

 be regarded as an instance in which that lobe and the 

 feeler coalesce into one ; and the mucro that proceeds 

 from the lobe has the aspect of an emerging feeler, and 

 corresponds somewhat with the labial one above no- 

 ticed a . In the remainder of the Neuroptera and the 

 Trichoptera, the prevailing number is Jive and three. 

 In the latter there are exceptions, which will furnish 

 good characters for genera. In the Lcpidoptera we find 

 two, and sometimes three, the maxillary being very mi- 

 nute b . The Diptera Order presents two tribes in this 

 respect quite distinct from each other. The most natu- 

 ral number of joints in the maxillary palpi of the Tipu- 

 lidce, Culicidae, &c. is four or five: the last joint, how- 

 ever, in Tipula, Ctenocera, &c. like that of the antennas 

 in Tabanus L., appears to consist of a number of very 

 minute joints c ; but in the Asilidac and Muscidce, &c, the 

 number two seems to be most prevalent^ The labial pal- 

 pi in this order are obsolete. — As to shape, the maxillary 

 palpi, as well as the labial, are usually filiform ; but in 

 the weevil tribes {Curcidio L.) they are most commonly 

 very short and conical e ; in the chafers (Scarabccus L.) 

 they usually are thickest at the apex f ; in Megachile and 

 Euglossa, wild bees, they are setaceous, growing gradu- 



a Plate VI. Fig. 12.b".f". 



b Ibid. Fig. 13. h". Savigny Anhn. sans Vertebr. I. i. 29 — . 

 L i. — iii. 6. c De Geer vi. /. xix./. 4. d. 



■' Ibid. t. ix.f. 8. b b. t. xii./. 20. b. t. xiv./. 15. i i. 

 e Plate XXVI. Fig. 6. f ' Ibid. Fig. 5, 



VOL. III. 2 G 



