ACTINOrODOrS HOLOTHURIOIDEA. 



23- 



nmv u 



FeinarJii^ : — My spociinens on the whole figrce well with tho 

 descri[)tioii of Thkel. Tlio largest sized one (No. 1082) measures 

 7.5 X l.i")cm. Body indistinctly pentagonal. Tentacles ten, the 

 two ventral ones smaller than the rest. Pedicels in double row 

 on each ambulacrum ; sometimes 3 — 4 rowed in certain parts, 

 but this condition is due jirobably to contraction. Polian vesicles 

 two. In one specimen, one of them is slender, and the other 

 vesicular ; in another, both vesicular. Stone-cnnal single, with a 

 distinct madreporic body. Greatest discrepancy from Thkel's 

 description is presented by the calcareous ring. This is bilaterally 

 symmetrical (textfig. 4Ca) ; 

 the interradialia on both 

 sides of the mid-ventral 

 radialia are fused with 

 the latter, thus forming a 

 large piece exhibiting three 

 points anteriorly and two 

 prolongations behind. The 

 lateral ventral radialia on 

 eaeli side of it has a single 

 point anteriorly and is pro- 

 longed posteriorly into two 

 long prolongations. The 

 two dorsal interradialia arc 

 k'af-like with a single point 

 forward, and are united to 

 the posterior prolongations 



Textfig. 46. 

 Cummaria clironJijebni : a — Ciilc:»reoim ring ; ';— 



of adjacent radialia. Tlietwo k««™1"K"1 fiip««: ;-S'"^p'! p''^"" ";f i^';'*'' = f • f- 



"' Elongnteil plates. (h—s x 300). I— Rifiht and left 



dorsal radialia are like the ventnl intemuliilii ; lU^Left ilorsal intom«lmIin ; Imd 



— MiiVloreiil intemulinlin ; 1? — RmlinlLi; Rmv — MidventinJ 



lateral interradialia, and the rmiiiJin. 



