Figure 4. Litotnosoides sigmodontis. Anterior end of female. 



5. Litomosoidcs sigmodontis. Posterior end of male. (Magnification 



same as figure 6.) 



6. Litomosoides sigmodontis. Head, much enlarged. 



7. Litomosoides .sigmodontis. Posterior end of female. (Magnification 



same as figure 6.) 



8. Filariopsis arator. Posterior end of male, lateral view. 



9. Filariopsis arator. Posterior end of male, ventral view. 

 10. Filariopsis arator. Posterior end of female. 



11 



U. S. GOVERNMENT PRINTING OFFICE: 19SI 



