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EXPLANATION OF PLATE IV. 



Fig. 1 . The tail of the female of Strongylus inflexus. 



a. Outlet of the alimentary canal. 



b. Outlet of the oviduct. 



Fig. 2. The tail of the male of Str. inflexus. 



a. Horn-like processes, with smaller ones projecting from their sides. 

 b b. Parallel striae on the expanded memhranous investment. 

 Fig. 3. Female genital apparatus of Str. inflexus. 



a. Ovarium. 



b. Oviduct. 



c. Uterus. 



d. Moniliform appearance of the uterus. 



Fig. 4. Ovum from the upper part of the uterus full of vitelline glohules. 



Fig. 5. Ovum in which the vitelline globules have diminished in number, but those 



remaining are much increased in size. 

 Fig. 6. Ovum showing the disappearance of the globules in one part. 

 Fig. 7. Ovum exhibiting the same appearance as the last, only more marked. 

 Fig. 8. Ovum exhibiting the young worm nearly developed. 

 Fig. 9. Ovum exhibiting the young worm perfectly developed. 

 Fig. 10. Head of male of Strongylus convolutus. 

 Fig. 11. Tail of male of Str. convolutus. 



a. Two dark curved bodies near the anal outlet. 



b. Three very minute horn-like bodies attached to the small semicircular 



fold of investing membrane. 

 Fig. 11a. Head of female of Str. convolutus. 

 Fig. lib. Tail of female of Str. convolutus. 

 Fig. 12. Tail of male of Str. minor. 



a. Three horn-like bodies attached to the investing membrane. 



b. Dark oval body near the termination of the alimentary canal. 

 Fig. 13. Tail of female of Str. minor. 



Fig. 14. Head of male of Str. invaginatus. 

 Fig. 15. Tail of male of Str. invaginatus. 



a. Two dark curved bodies similar to those in fig. 11a. 

 Fig. 16. Tail of female of Str. invaginatus. 



b. Two minute hooks near the vulva. 

 Fig. 17. Head of male of Str. inflexus. 



A represents the average length of the female, Str. invaginatus. 



B 

 C 

 D 

 E 

 F 



male, Str. invaginatus. 

 male, Str. convolutus. 

 female, Str. convolutus. 

 male, Str. minor. 

 female, Str. minor. 



