PLATE V. 



a, anal opening, 

 ma] of arm. 



,.7 . imperforate plates of anal interradium. 



br, first fork of arm. 



g, food groove. 



i;'. ambulacra] groove of pinnule. 



cp, covering plates. 



o, oral plates. 



p, perforated plates of interradium of disk. 



pl, plates in continuation of disk, interradial plates 



extending along the base of the pinnules. 

 ]>n'. fi ist pinnule. 



econd pinnule. 

 r, first radial. 

 sp, .side plates. 

 si, subtentacular canal. 

 i, ambulacra] tentacles. 

 s, syzygy. 



1. [tight anterior interradial, showing the intimate connection of the interradial plates to the radials, 



and to the lower joints of the first pinnules, \. Specimen No. 8. 

 ■J Anal interradium of same specimen, J. 



8 I ! end of anal tube of specimen No. 7, seen obliquely from above. 

 4. Showing extension of imperforate interradial and perforated perisomatic plates to the main food 



groove, and along the side of the arm, as far as the first axillary, *. 

 5 Showing the further continuation of the interradial skeleton along the sides of the arm below the 



side plates (*/>), beyond the first fork of the arm, \. 

 Showing side plates protecting the food furrow in middle of first arm. These side plates are not a 



part of the extension of perforated perisomatic plates. 



7. Showing the extension of the plates of the disk along the base of one of the pinnules placed below 



the first fork of the arm. 



8. Same pinnule seen facing the ambulacral food groove. 

 'J. Tentacles of ambulacral furrow. 



