xVCTINOPODOUS HOLOTHUEIOIDEA. 



125 



two ambulacra are lecognizable (Nos. 1223, 1225). In some (No. 

 1227) the body is cylindrical and the pedicels are arranged in 

 five ambulacral zones, especially obvions near the anus. In all, 

 dorsal appendages seem to have the end -plates more weakly 

 developed than in the ventral pedicels ; still in some they are 

 tolerably well developed, while in others they are very small ; 

 in fact, it is very difficult to make a clear distinction botween 

 pedicels and papilla3. 



Calcareous deposits are tables and buttons. Buttons in groups 

 which are visible to the naked eye or at least under a hand lens. 

 In one specimen, the grou2}s measured in diameter 0.17, 0.24, 0.32, 

 0.40 mm. In the Ogasawara specimen (the larger cue of No. 1223), 

 the gronps are in the shape of rings. In some (No. 1224,) these 



are covered over with tables 

 so that at first sight they 

 appear more like groujDS of 

 tables than of buttons, while 

 in others they are obvious from 

 the outside. The buttons are 

 either (i) complete and then 

 mostly provided with three 

 pairs of openings (textfig. 22 e) 

 or (ii) half- sided [d). Occa- 

 sionally (iii) there are some 

 which are reduced to tlie 

 central red only with bent 

 ends, so that a short thick 



Textfig. 22. 



„ , ,, . , ,. , ,n,, -., . C-shape may be produced 



llo.ot/ivrii jrirJalis : a, h. — Tal)les with spiny -*■ "^ ^ 



m.irgin; c— table with smooth mnrgin ; d — half- (NOS. 1229 1133). ThcrO arC 

 sided button ; e — ordii:ary button ; /, g — suppoiting 



rods seen from different sides. ( x 300). all sorts of intermediate forms 



