PLATE VI. 



ac, 



nn, 



ax, 



cp, 



!/' 



'>. 



canal of arm. 



anal opening. 



axial canal. 



covering plates. 



ambulacral furrow. 



imperforated interradial plates. 



the same, seen in section. 



oral plates. 



perforated plates of interradium. 



1 Oral di.sk of specimen No. 7 seen from above, showing limit of imperforated plates, {. 



2. Mouth of specimen No. 1. 



S. Oblique view of food furrow extending from the mouth to the pinnules, to show the connection 



of the base of the pinnules with the disk ; the left posterior groove adjoining anal interradium 



of specimen No. 1. 



4. Oblique view to show junction of perforated and impeforated interradial plates of disk, from 



specimen No. 8. 



5. Seen facing the odd "anterior arm, to show the vault formed by the perforated and imperforated in- 



terradial plating on each side of the arm, supporting the arm canal (ac), the subtentacular canal, 

 and the food groove (c/). Specimen No. 7. 



Figs. 6-10 from specimen No. 1. 



6. Oblique view of arm showing the continuity of the plating of the vault flanking the arm canal, 



the subtentacular canal, and the food groove. 



7. Interior view of part of food groove adjoining the oral plates, together with the contiguous sub- 



tentacular canal, arm canal, and the lower part of the interradial plating of the adjacent arm. 



8. Interior view of the upper part of the vault, showing ai-m canal, pinnule canals, and the plating of 



imperforated plates ; the left pinnule canal should be lettered pc. 



9. Interior view of the upper part of the vault, and the adjacent subtentacular canal and food groove, 



facing the angle of the oral plates. 

 lO. Irregular plates forming the bottom of the food furrow seen from the interior of the disk. 



i 



