1915-16.] Structure and Life-History of Bracon sp. 333 
In conclusion I wish to acknowledge my indebtedness to S. J. Gammell, 
Esq., of Countesswells, for permission to collect Bracon cocoons on his 
estate, and to Dr R Stewart MacDougall for his kind advice and 
assistance throughout my work. 
EXPLANATION OF PLATES. 
Plate I. 
Fig. 1. Male of Bracon sp. x 8. 
Fig. 2. Female of Bracon sp. x 8. 
Fig. 3. Egg. x 70. 
Fig. 4. First-stage larva. x 60. 
Fig. 5. Third-stage larva. x 20. 
Fig. 6. Fourth-stage larva. x 12. 
Fig. 7. Fifth-stage larva. x 15. 
Fig. 8. Pupa in cut-open cocoon. 10. 
Plate II. 
Fig. 9. Head and prothorax of larva of H. abietis showing head (h)- } (/) 
epicranial furrows distinguishing it from the larva of P. notatus ; and ( p ) the 
prothoracic segmental plate. Magnified. 
Fig. 10. Larva of H. abietis. Notice the elliptical spiracles. 
Fig. 11. Pupa of H. abietis. Magnified. 
Fig. 12. H. abietis , adult. Magnified. 
Fig. 13. Fore part of H. abietis larva, to show in situ eggs of Bracon. Highly 
magnified. 
Fig. 14. Larva of H. abietis in cavity on hark, with Bracon larvae feeding on it, 
Magnified. ' 
Fig. 15. Batch of Bracon cocoons, showing exit holes (e) and head of the dead 
Hylobius larva (h). 
{Issued separately March 1, 1917.) 
