122 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxiii. 



Fig. 9. Transverse section back of pharynx showing structure of esophagus; 

 diameter, 0.13 mm. 



10. Transverse section of esophagus of specimen from Micropogon undulatus, 



Beaufort, North Carolina, introduced here for comparison; diameter, 

 0.08 mm. 



Heterakis, species. 



11. Lateral view of female from Neoma'nis griseui^, l)alsam; length, 6 mm. 

 I la. Lateral view of same, enlarged. 



116. Posterior end, ventral view of female from Hivniulon carbonariuin. 



12. Nearly transverse section of lips showing four of the mouth papillpe and 



the teeth; length of section, 0.12 mm. Figs. 12 to 15 are made from a 

 specimen collected at Beaufort, from the southern flounder {ParaJicJithyx 

 alhigutlus). 



13. Sketch, somewhat diagrammatic, of anterior end of pharynx; breadth of 



gap of mouth, 0.11 mm. See fig. 15. 



14. Section behind pharynx showing structure of esophagus; diameter, 0.25 



mm; a, lateral area; m, muscle cell. 



Plate HI. 



Heterakis, species, continued. 



Fig. 15. Section of posterior end of pharynx, showing the division of the cuticle into 

 three parts which become the three symmetrical longitudinal divisions 

 shown in fig. 14; breadth of gap, 0.10 mm. 



16. Dorsal view of specimen shown in fig. 11, enlarged. 



17. Cross section of anterior end of specimen from Neomsenis grisens, partly 



diagrammatic; breadth of section, 0.17 mm. 



18. Cross section of pharynx, showing beginning of divisions of cuticle into 



three parts; maximum diameter, 0.26 mm. 



19. Section a little behind that sketched in fig. 18. Note the very thick cuticle; 



pa, pulp of papilla; maximum diameter of section, 0.30 mm. 



20. Cross section of esophagus, near base; maximum diameter, 0.14 mm. 



Plate IV. 



Erhlnorhynchus medius, new species. 



Fig. 21. Adult male with bursa everted, from Mycteroperca apua; in balsam; length, 

 40 mm. b, bursa; eg, cement gland; /, lemnisci; ps, proboscis sheath. 



22. Anterior end of female, proboscis and neck everted; length of proboscis, 



1.35 mm. 



23. Another, anterior end of body partly inverted; length of proboscis, 1.28 



mm.; a, spine from body enlarged; actual length, 0.04 mm. 



24. Transverse section of proboscis, middle; diameter, exclusive of hooks, 



0.4 mm. 



25. Same, near base; rm, retractor muscle. 



26. Immature male from Calamus calamus; balsam; length, 12 nun. 



27. Immature female; balsam; length, 14 mm. 

 28-30. Hooks from proboscis, enlarged; length, 0.08 mm. 



