PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1686 



EXPLANATION OF PLATE XX. 



Protula diomedece Benedict, ep. nov. 



Fig. 1. Thoracic uncinus, enlarged 650 diameters. 

 Fig. 2. Abdominal uncinus, enlarged 650 diameters. 

 Fig. 3. Long thoracic setae, enlarged 433 diameters. 

 Fig. 4. Anterior abdominal setae, enlarged 433 diameters. 

 Fig. 5. Posterior abdominal setae, enlarged 433 diameters. 

 Fig. 6. Tube, natural size. 



Protula americana Mcintosh. 



Fig. 7. Anterior uncinus, after Mcintosh, enlarged 700 diameters. 



Protula alba Benedict, sp. nov. 



Fig. 8. Abdominal uncinus, enlarged 650 diameters. 

 Fig. 9. Anterior abdominal sette, enlarged 433 diameters. 



Sydroides dianthua Verrill. 



Fig. 10. Spine of operculum, showing conical process at base, enlarged 43 diameters. 



Hydroides spongicola Benedict, sp. nov. 



Fig. 11. Spine of operculum, enlarged 43 diameters. 

 Fig. 12. Operculum, enlarged. 



Sydroides protulicola Benedict, sp. nov. 



Fig. 17. Large spine of operculum, showing protuberance on inner base, enlarged 

 43 diameters. 



