THE PYCNOGONIDS. 75 



the first with eight segments, the second with eight, the third with 

 six. 



Fig. XVIII, stage 8. Ventral view with four pairs walking legs, 

 the first with eight segments, the second with eight, the third with 

 eight, the fourth with six. 



Plate VI. — Larv^ and Adult of Tanystylum. Larva of 

 Phoxichilidium. Larva of Pallene. 



Fig. XIX, stage 9. Tanystylum. Ventral view. Showing re- 

 newed growth of third pair of appendages. Zeiss 4 A h 



Fig. XX, stage 9. Dorsal view of last. Showing rudiments of 

 first appendages. Zeiss 4AJ. 



Fig. XXI, stage 10. Tanystylum. Ventral view. Showing seg- 

 mentation of third appendages, and fusion of first, second and third 

 ventral ganglia. Zeiss 4 A h 



Fig. XXII. Adult Tanystylum. Dorsal view. Proportionately 

 less magnified. 



Fig. XXIII. Ovigerous leg and eggs of Tanystylum. Zeiss 2 A h 



Fig. XXIV. Adult Phoxichilidium. Side view of male with eggs. 

 X30. 



Fig. XXV. Pantopod-larva of Phoxichilidium. 



Fig. XXVI. Larval Pallene. Ventral view. Showing the unde- 

 veloped third pair of appendages. 



Plate VII.— Eyes of Phoxichilidium, 30-36. Pallene, 37. 

 Tanystylum, 38-39. Zeiss 4 D I, except Fig. 31. 



Fig. 30. Eye of Phoxichilidium, viewed on the inner side, from 

 a macerated preparation. Showing distribution of nerve to eye and 

 bilateral arrangement of elements along the raphe. 



Fig. 31. Section across cupola, containing the eyes which are cut 

 into " cross sections " (horizontal with reference to body). 



Fig. 32. Cross-section of eye as in 31, but more magnified. 



Fig. 33. Longitudinal section of eye, parallel to raphe. 



Fig. 34. Section in plane at right angles to other two. Showing 

 bacillar ends of the elements of the retina, forming by their union 

 the raphe. 



Fig. 35. Section in same plane, but further out than last. 



Fig. 36. Section in same plane, but nearer the center of the eye. 



Fig. 37. Longitudinal section of eye of Pallene. 



Fig. 38. Longitudinal section of eye of Tanystylum. 



Fig. 39. Inner view of cells forming raphe of Tanystylum. 



