INTRODUCTORY REMARKS. 41 



its vagina from most of his genera, either under 

 the name of lingua or proboscis ; but this is con- 

 trary to fact, for all Hymenopterous insects are 

 furnished with 3. proboscis consisting of the follow- 

 ing parts, viz. a central tongue defended by two 

 valvulceik), laterally palpigerous(/), and a tube{m), 

 just above the apex of which, or from the exterior 

 lacinice the interior palpi emerge (;z). This part, 

 though not equally conspicuous in all, exists in all ; 

 and its mere direction, whether it is inflected or 

 not, can make no difference as to its title to the 

 name of proboscis. In v4pis, Ammophila (o), the 

 genuine J^espce, Philanthus, Crabro, many SpheceSy 

 Chrysis, and Tenthredo, this part may be examined 

 with as much ease as the Instrument a oris of the 

 Diptera. But in Cynips, Ichneumon Tiphia, For- 

 mica (p), and the petiolated Spkeces{q), it is not 

 so readily inspected, nor, in these, is it easy to get 

 a distinct idea of it, unless it be nicely extracted 

 from the head of the insect, and put under a 

 strong magnifier. 



In the construction of the Essential Characters 

 of the genera in this class, the form of the tongue, 

 where sufliciently conspicuous, might be added to 



(k) Tab. 11. **. d. 2. a. fig. l.g,cc. (I) Ibid. hh. 



(7«)lbid. d. («)Tab. 1. *.a. fig. 3. bb. &Tab. 11. ubi supra if. 



(o) I have ventured to separate Sphex sabulosa and its affini- 

 ties under this name from Sphex in a paper published in tlie 

 fourth vol. of the Linnean Transactions, to which I refer the 

 reader. Vid. p. 195. {p) De Geer, torn. 2, P'«. 2. Tab. 41. 



f^g.7. (ry) Tab. J4.N° 3. 



the 



