34 



CESTRUS ovis, Liuu. 



Plate I. 



Fig. 1. Larva in the first stage. Dorsal view. 



Fig. 2. Larva in the first stage. Veutral view. 



Fig. 3. Head of larva iu the first stage: a, hooks hy which the parasite attacheg 

 itself to the mucous meuibrane. 



Fig. 4. Tail of larva in the first stage : a, the stigmata or breathing ijorcs. 



Fig. 5. Hooks of well-developed larva. 



Fig. 6. Hooks of very young larva. 



Fig. 7. Larvic in various stages of growth ; natural size: a, a, a, fully developed 

 larva) in the third stage ; h, throe-fourths developed ; c and ti, yet younger 

 larvae, possibly in the second stage ; e, the youngest found, and tlioso from 

 which figures from 1 to 4 were taken. 



Fig. 8. Cephalic end of full grown larva (Brauer). 



Fig. y. Dorsal view of full grown larva (Brauer). 



Fig. 10. Caudal end of full grown larva (Brauer) : a, stigmata or breathing pores. 



Fig. 11. Adult female fly .with line indicating natural length (Brauer). 



Fig. 12. Front view of head of the above (Brauer). 



Fig. 13. Ventral view of full grown larva, showing the spines which enable the para- 

 site to push itself along the smooth, soft mucous membrane. 



Fig. 14. Pupa case dissected to show the imago or young fly within (Raillet). 



Fig. 15. Eggs taken from fly (Raillet), 



