PLATE XIII. 



Heterochceta spinifrons, Claus. 

 Fi°-. l. Female, seen from above, magnified 20 diameters. 

 Fi°\ 2. Anterior antenna of female. 

 Fio-. 3. Left anterior antenna of male. 

 Fie 4. Posterior antenna. 

 Fig. 5. Mandible and palp. 



Fie. 6. Maxilla. 



Fig. 7. Anterior foot-jaw. 



Fig. 8. Posterior foot-jaw. 

 Fig. 9. Outer branch of third swimming foot. 



Fig. 10. Fifth pair of feet of male. 



Fig. 1 1 . Fifth pair of feet of female. 



Fig. 12. Abdomen of female, with spermatophore attached. 



Fig. 13. Portion of spermatophore, with spermatozoids, more highly magnified. 



