PLATE XXII. 

 Tliysanoessa gregaria, G. 0. Sars. 



Fig. 9. Terminal joint of same ; more highly magnified. 



Fig. 10. Leg of first pair, with .gill and luminous organ. 



Fig. 1 1 . Leg of second pair, with attached gill. 



Fig. 12. Extremity of same ; more highly magnified. 



Fig. 1 3. Leg of third pair, with gill. 



Fig. 14. Leg of fourth pair, with gill. 



Fig. 15. Leg of fifth pair-, with gill. 



Fig. 16. Leg of penultimate pair, with giU and luminous organ. 



Fig. 17. Gill of last pair, with rudiment of leg. 



Fig. 18. Leg of penultimate pair, without gill and luminous organ ; more highly magnified. 



Fig. 19. Rudimentary leg of last pair. 



Fig. 20. Gill of second pair. 



Fig. 21. Gill of third pair-. 



Fig. 22. Gill of fourth pair. 



Fig. 23. Gill of fifth pair. 



Fig. 24. Gills of the two posterior pairs, on right side, in siUi, from outer face. 



Fig. 25. Spermatophores affixed to the genital openings of a female specimen. 



Fig. 26. Extremity of tail, with caudal fan, from above. 



Fig. 27. Inner plate of a male pleopod of first pair. 



Fig. 28. Inner plate of a male pleopod of second pair. 



Fig. 29. Copulatory appendage to first pleopod, isolated, and more highly magnified. 



Fig. 30. Tip of copulatory appendage to second pleopod. 



