ACTINOrODOUS HOLOTHUKIOIDEA. 199 



additions or emendations us to other parts. (1) Tjatural pedicels 

 are said by Thkel to be " apparently disposed in a double row 

 all along each side of that surface." I am inclined to think that 

 the lateral pedicels are in one series along the side of the body, 

 and that they appear double only as the result of contraction. 

 [2) The " crowded series of dorsal processes " are, in I. ijimal 

 at least, always in four rows on the dorsal surface or in two rows 

 in each longitudinal half. That is, on the sides of each dorsal 

 ambulacrum there is an alternating double series of slender dorsal 

 papilla^, and, when they are looked at from the inside, the ambula- 

 cral vesicles of these papilla) form one series on each side of the 

 longitudinal muscle, A& emended, the definition of the genus 

 should be as follows : — 



Tentacles 15, rather large and non-retractile. The lateral 

 ambulacra of the ventral surface with large pedicels, arranged in 

 a single series along each side of the body, often appearing in 

 alcohol specimens as if they were disposed in a double alterna- 

 ting row. The odd ambulacrum naked. The dorsal surface with 

 a series of very numerous retractile, slender, rather long processes, 

 disposed generally in two alternating rows on the sides of each 

 dorsal ambulacrum, but often appearing crowded on account of 

 contraction. Internally, a series of ambulacral vesicles correspond- 

 ing to each double row, is seen on each side of the longitudinal 

 vessel. Integument with niunerous wheels, sometimes also with 

 dichotomously branched bodies. 



SLurrEK (1901fc, p. GO) expresses doubt as to the possibility of 

 keeping Laimocione and Ilyodicmon separate. He says " Ich glaube 

 dass es in der Zukunft kaum moglieh sein wird, die beiden 

 Genera Laimoijone und Ilijochvmon nebeneinander zu behalten." 1 

 was at first inclined to accept this view, but further study has 



