243 



EXPLANATION OF THE PLATES. 



All the drawings of the tongues were made from specimens 

 of those organs when recently extracted from fresh specimens of 

 the Bees^ before any of the parts became distorted by shrivelling 

 up, as is the case in dried specimens. 



The letters indicate the same parts in all the figures ; they are 

 as foUow^s : a, the mentum ; by labium ; c, the labial palpi ; d^ the 



maxillary palpus. 



/ 



b. 

 c. 

 d. 



e. 





PLATE A.— Fig, 1. 



a. The costal nervure. 



The apical margin. 

 The posterior margin. 

 The post-costal nervure. 

 The externo-medial ner- 

 vure. 

 The anal nervure. 

 The transverso-medial ner 

 vure. 



r 



h. The radial nervure. 



i. The cubital nervure. 

 k. The discoidal nervure. 



L The subdiscoidal nervure 

 m. The transverso-medial 



0. 



nervures. 

 The recurrent nervures 



The stigma. 



PLATE A.— Eig. 2. 



1 . The costal cell. 



2. The externo-medial cell. 



3. The interno-medial cell. 



4. The anal cell, 



5. The marginal cell. 



6. The first submarginal cell, 



7. The second submarginal 



cell. 



8. The third submarginal cell. 



9. The fourth submarginal 



cell. 



10. The first discoidal cell. 



11. The second discoidal cell. 



12. The third discoidal cell. 



r 



13. The first apical cell. 



14. The second apical cell, 



m2 



