PLATE X. 



Fitfiire* magnified 500 diameters. 



V\r,r. 



Fig. 1. Docidittm \ ii.tk ii. i. ati m. . . . 53 



'* 2. DociDniM COSTATUM, . . . . . . 53 



''. Docidium i. km ii. i. i;n_. form; whorls evidently composed of two 



rows of teeth, ..... 53 



1. DociDruM verrucosi m. vegetative state, . . . 52 

 ">. empt\ semicell, shows the arrangement of 



the verrueae, .... -VJ 



6. DociDrcM gracilis, empty semicell, ... . 53 



" 7. empty semicell, older condition before breaking 



into parts, . . . 53 



' - small form, ..... 53 



9. Docidii m minium. Var., Se< Plate I.. Bg8 29 31, . . 52 



" 10. I >OCIDIUM I i;iih A I I 1 .1 m. . . . . 52 



li. DociDiiw \ i i: i h 1 1 i. a i r m. Var. turgidum, .... 53 



' 12. Docidii m spinosi m. ..... . ; >1 



" 13. docidium hirsutum, . . . . . . .51 



