CRUSTACEA MALACOSTRACA. IV. 79 



EXPLANATION OF THE PLATES. 



Plate I. 



Fig. 1. Leucon spinidosus n. sp. 



Fig. 1 a. Cephalothorax of a female with marsupium from the "Ingolf" Stat. 24, from the left side; X 30. 

 Major part of the siphon omitted. 



— ib. Anterior part of carapace of an ovigerous female from the "Ingolf" Stat. 36, from the left side; 



X 50. 



1 c. Left second leg of an ovigerous female from the "Ingolf" Stat. 36, from below; x 41. Major 



part of second joint omitted. 



— 1 d. Left uropod of an immature female from the "Ingolf" Stat. 24, from above; x 76. 



Fig. 2. Leucon tener n. sp. 



Fig. 2 a. Carapace of an ovigerous female, from the left side; ■ 45. 



2 b. Distal part of left first leg of an immature female from the "Ingolf" Stat. 97, from below; x 52. 



— 2 c. Left uropod of an ovigerous female, from above; X 52. 



Fig. 3. Leucon spiniventris n. sp. 



Fig. 3 a. Immature female, from the side; x 13. Distal half of abdomen omitted. 



— 3 b. Anterior part of carapace with left antennula of the same female, from the side; x 25. 



— 3 c. Three posterior thoracic segments and first abdominal segment of the same female in order to 



show the ventral and marginal processes, from the side; x 19. 



— 3d. Left uropod of a female with marsupium, from above; X 37. 



Fig. 4. Leucon profundus n. sp. 



Fig. 4 a. Cephalothorax of a female with marsupium from the "Ingolf" Stat. 24, from the side; x 35 .->. 



— 4 b. Anterior part of carapace with left antennula of the same female; x 36. 



— 4 c. Deft first leg of a female with the marsupium half developed, from below; x 32. Exopod omitted. 



— 4 d. Left uropod of a female from the "Ingolf" Stat. 36, from above; x 31. 



Fig. 5. Leucon Nathorstii Ohlin. 



Fig. 5 a. Left first leg of a female with marsupium from Jan Mayen, from below; x 40. 



— 5 b. Left uropod of an adult female from Jan Mayen, from above; X 44. 



