200 DESCRIPTION OP THE PLATES. 



Plate V. 



Fig. 1. Spicules of Thyone fusus, the two lower x 450 to show the 



details of those figured on their right (p. 42). 

 Fig. 2. Spicules of Thyone raphanus (p. 42). 

 Fig. 3. „ Phyllophorus pellucidus (p. 46). 



Fig. 4. „ ,, drummondi (p. 47). 



Plate VI. 



Fig. 1. Spicules of Psolus phantapus (p. 44). 



Fig. 2. „ „ fabricii : a, from the body-wall ; b, from 



the podia (p. 45). 

 Fig. 3. Spicules of Holothuria intestinalis (p. 48). 

 Fig. 4. „ „ tremula (p. 49). 



Fig. 5. „ „ nigra (p. 49) ; the three uppermost 



x 450 to show the details of those which lie just below 



them. 



Plate VII. 



Figures of external forms of Holothurians, from specimens 

 preserved in spirit. 



Fig. 1. Synapta digitata, nat. size (p. 31). 



Fig. 2. Tentacles of Synapta digitata, x 6, to show the arrange- 

 ment of the pinnae on the tentacles. 

 Fig. 3. Thyone fusus, nat. size (p. 42). 

 Fig. 4. Phyllophorus drummondi, nat. size (p. 47). 



Plate VIII. 



Figures of external forms of Holothurians ; figs. 1, 2, and 5 from 

 life, 3 and 4 from spirit-specimens. 



Fig. 1. Cucumaria planci, X§ (p. 37). 

 Fig. 2. Cucumaria pentactes, X | (p. 37). 

 Fig. 3. Thyone raphanus, x 2 (p. 42). 

 Fig. 4. Psolus phantapus, nat. size (p. 44). 

 Fig. 5. Holothuria nigra, X § (p. 49). 



Plate IX. 



Figures to illustrate the structure and variations of 

 Antedon bifida (p. 54). 



Fig. 1. Dorsal view of disk to show the cirrus-pits (cp), the modes 

 of branching of the arms, the form of the radials (R 3 ), 

 and a syzygy (sz), x 8. 



