WILSON, PARASITIC COPEPODS FROM JAPAN. 17 



Explaiiation of the plates. 

 Plate I. 



Fig. 1. Dorsal view of female Argulus caeciis. Fig. 2. First and se- 

 cond antennae. Fig. 3. Three of the rods which support the flexible mar- 

 gins of the sucking disks. Fig. 4- Maxilliped. Fig. 5. Respiratory areas. 

 Fig. 6. Young developmental stage of Phrixocephalus diversus. Fig 7. 

 OIder stage of same, side view. 



Plate II. 



Fig. 8. Adult female Phrixocephalus diversus, dorsal view of head 

 and thorax, side view of trunk. Fig. 9. Adult female Achtheinus japonicus. 

 Fig. 10. Developmental stage of same. Fig. 11. Second antenna. Fig. 12. 

 First maxilla. Fig. 13. Maxilliped. Figs. 14 — 17. First, second, third and 

 fourth swimming legs. 



Plate III. 



Fig. 18. Dorsal view of female Taeniacanthus coelus. Fig. 19. Side 

 view of same. Fig. 20. First antenna. Fig. 21. Second antennae and 

 mouth parts. an-, second antennae; Ib. labrum ; md. mandible ; mx^. first 

 maxilla; mx"'. second maxilla; mxp. maxilliped. Figs. 22 — 26. First, se- 

 cond, third, fourth and fifth swimming legs. Fig. 27. Mandible and palp 

 of female Chondracanthus sixteni. Fig. 28. Maxilla of same. Fig. 29. 

 Maxilliped. Fig. 30. Maxilliped of male. 



Plate IV. 



Fig. 31. Dorsal view of adult female Chondracanthus sixteni. Fig. 32 

 Side view of male of same. Fig. 33. Ventral view of adult female Chon- 

 dracanthus distorius. Fig. 34. Dorsal view of same. Fig. 35. Side view 

 of male. Fig. 36. Second antenna of female. Fig. 37. Mandible and palp. 

 Fig. 38. Maxilla. Fig 39. Maxilliped. 



Tryckt den 11 januari 1922. 



Arkiv för zoologi. Band 14. N:it 10. 



