230 Charles Lincoln Edwards 



EXPLANATION OF PLATES. 

 All figures were drawn with the aid of an AbbS camera lucida, from prepara- 

 tions of Holothuria floridana Pourtal6s. 



ABBREVIATIONS. 



a, b, c, d, e, first, second, third, fourth and fifth pedicels from the mid- 

 ventral radial canal. 



bl., blastopore. 



dl, d2, first, and second, tentacles developed dorsad from a given radial canal. 



D., dorsal. 



ect., ectoderm. 



ent., enteron. 



11, 12, first and second tentacles developed to the left from the mid-ventral 

 radial canal. 



LD., left dorsal radial canal. 



Idpal, ldpa2, ldpa3, first, second, and third, left dorsal papillae. 



Ivp., first pedicel developed ventrad from the' left ventral radial canal. 



LV., left ventral radial canal. 



m., mouth. 



mes., mesoderm 



MV., mid-ventral radial canal. 



MVrp., first pedicel developed to the right from the mid-ventral radial 

 canal. 



p., peristome. 



pvp., posterior ventral pedicel. 



rl, r2, first and second tentacles developed to the right from the mid-ventral 

 radial canal. 



RD.. right dorsal radial canal. 



rdpal, rdpa2, rdpa3, first, second, and third, right dorsal papilke. 



rvp., first pedicel developed ventrad from the right ventral radial canal. 



RV., right ventral radial canal. 



t, larval table. 



v., ventral. 



vl, v2, first, and second, tentacles developed ventrad from a given radial 

 canal. 



vra., vitelline membrane. 



vpv., vaso-peritoneal vesicle. 



vv., lateral anal plates. 



XX., anterior papillae, developed dorsad from the right and left dorsal radial 

 canals. 



y., posterior anal plate. 



