INTRODUCTORY REMARKS. 5'j 



stead of '^ Corpus glabrum." The first member of 

 this character is often only a sexual distinction. 

 The second is partly common to the whole class, 

 and partly peculiar to genuine yipes. With re- 

 spect to the third, the aculeus of all Hymenopterous 

 insects, as far as I have had an opportunity of 

 examining them, consists of the same parts, viz. 

 two valves (l), and a central vagina {m), exerting a 

 pair of spicula {n) barbed or serrated more or less 

 on one side. In most genera the aculeus when 

 unemployed is recondite, or withdrawn within the 

 abdomen, but in a large proportion of the Ichneu- 

 mons (p), Sirex(p), &c. both valves and vagina 

 are exerted. So that the term " simplex" cannot 

 with propriety be applied to one aculeus more than 

 another. " Subulatus" very properly defines the 

 vagina of the spicula of an ^pis. The next mem- 

 ber of the character is common to many genera ; 

 the fifth to the whole class ; and the last excludes 

 all those Vespiform bees (Nojnada, Fab.) which 

 evidently belong to this genus. This author 

 adopts the families of Linneus. 



De Geer's definitions of the two genera, into 

 which, after Reaumur, he divides ^pis, are now to 

 be considered, they are as follows ; 



(I) Tab. 13. fig. 27. bh. fig. 28. aa. (?n) Ibid. fig. 2/. a. 

 28. c. and 2Q. (n) Ibid. fig. 28. bl. and 30, 31. 



(0) Marsham in Linn. Trans, vol. 3. p. 29. Tab. 4. fig. 5. 

 ip) Reaum. torn. 6. Mcra. 9. Tab. 31. fig. 3. ffi. 



APIS. 



