PLATE 4. 



Fig. 1. Thysanopoda cristata G. O. Sars. 



Left antennular peduncle of the adult male, from the outer side; X 8. 

 Right antennular peduncle of the adult male, from above; X 8. 



Left antennular peduncle of the young specimen from Sta. 4699, from the left side; X 14. 

 Left maxillula of the immature specimen from Sta. 4736, from below; X 31. 

 Male copulatory organ of left first pleopod, unrolled and seen from behind; X 25. h. 

 inner lobe; Im. median lobe; Is. setiferous lobe — the setae along both margins omitted; lu. auxihary 

 lobe; p'. spine-shaped process; p''. terminal process; p'. proximal process; p''. lateral process. 

 Fig. If. Terminal process of the organ shown in fig. le, from behind; X 45. 

 Fig. Ig. Terminal process of the organ shown in fig. le, from the inner side; X 50. 

 Fig. Ih. Distal part of the median lobe of the organ shown in fig. le, seen from in front and ex- 

 hibiting the lateral process and the additional process; X 45. 



Fig. 2. Thysanopoda tricuspidata H. Milne Edwards. 



Fig. 2a. Left maxillula of an adult specimen, from below; X 32. 1. first joint; 1'. lobe from first 

 joint; 2. second joint; 3. third joint; IMobe from third joint; 4. fourth joint or palp; px. pseudexopod. 



Fig. 3. Thysanopoda monacantha Ortmann. 



Fig. 3a. Left maxiUula of a probably immature male, from below; X 34. The lettering as in 

 fig. 2a. 



Fig. 3b. Inner and median lobes of left copulatory organ of aprobably immature male, from behind; 

 X 85. The median lobe has the lateral process and only one additional process. 



Fig. 3c. Inner and median lobes of left copulatory organ of another probably immature male, 

 from behind; X 85. p'. lateral process; p^ three additional processes. 



Fig. 4. Thysanopoda aequalis H. J. Hansen. 

 Fig. 4a. Left maxillula of an adult female, from behind; X 35. 



Fig. 5. Thysanopoda obtusifrons G. O. Sars. 



Fig. 5a. Anterior part of the body of a female, from above; X 15. The setae on left antennula 

 omitted. 



Fig. 5b, Anterior part of a female, from the left side; X 14. 



Fig. 5c. Left maxillula of an adult male, from below; X 30. 



Fig. 5d. Left copulatory organ, unrolled and seen from behind; X 48. p'. lateral process; p'. 

 additional process. 



Fig. 5e. Inner and median lobes of left copulatory organ, from the inner side; X 60. p'. spine- 

 shaped process; p'. terminal process; p^ proximal process; p'. lateral process; p*. additional process; 

 lu. margin of the auxihary lobe with its minute couphng hooks. 



Fig. 5f. Distal part of the proximal process of the organ shown in fig. 5e, from the inner side; X 

 130. 



