PLATE XVII. 



Fig. 1. Pentacrinus macleaeanus, Wyv. Thorns. 



Diam. Page 



Fig. 1. Arm-gvoo-ve oi Pentacrinus 7naclearanus, . . . x 8 80 



Figs. 2-6. Pentacrinus wyville-thomsoni, Jeffreys. 



Fig. 2. Ambulacral skeleton of a pinnule ; from the siJe, , . x 



Fig. 3. The same, near the base of the pinnule ; from above, . x 



Fig. 4. The arm-groove and In-achial ambulacrum, . . . x 



Fig. ."). Vertical section of a decalcified specimen. Much of the alimen- 

 tary epithelium has fallen away. The lobulated organ to 

 the right of the centre of the figure is the plexiform gland, x 3 33 



Fig. 6. The disk of a dry specimen, . . . . . x 6 320 



Figs. 7, 8. Pentacrinus asterius, Linn, sp. 



Fig. 7. Ventral aspect of one of the lower arm-divisions, showing tlie 



ambulacral skeleton, . . . . . x 8 79 



Fig. 8. The arm-groove and In-achial aml)uhierum, . . . x S 79 



Figs. 9, 10. Pentacrinus MiJLLERi, Oersted. 

 Fig. 9. Tlie arm-groove and brachial amliulacrum. . . . x 8 80 



Fig. 10. The disk of a spirit-specimen, , . . . x 3 311 



