ACTIXOrODOUrt HOLOTHUKIOIDEA. 



211 



tlu'ougli tlio intervals between the spokes. The crown in the 

 center is usually of the triradiate type and shows generally five 

 openings. The " iJcck- 

 platte " closes this from 

 below, and there may 

 be one or more— up to 

 several — openings in this 

 plate. The wheels in 

 question are very large, 

 the largest reaching 

 0.216 mm. in diameter. 

 They may be as small 

 as 0.072 mm., but such 

 are not very numerous. 

 In my sj^ecimens they 

 are largest in the dorsal 

 ])erisome. Small wheel-like plates have always foiu- holes in the 

 center, and 10 — 1 1 in the periphery (c). They are circular or slightly 

 oval. In the former case, the diameter is 0.044 — 0.05G mm. ; in 

 the latter case, 0.05G mm. in longer diameter and 0.048 ram. in 

 shorter diameter (in one specimen, 0.050 and 0.0r)2 mm. respective- 

 ly). In the dorsal papill;:e, largo wheels and wheel-like plates are 

 present up to very near the tip ; but near the tip, there are only 

 wheel-like plates. There are no end-plates, but there exist some 

 weak supporting rods. In the ventral pedicels, there is a large 

 irregularly large- and small-mcshed end-plate. Around and over 

 the end-plate there are irregular X-shaped supporting rods {d). In 

 tlie lateral walls, there occur also some spinose supporting rods. Like 

 LuDwiG I can not detect any wheel-like plate which is like Thkel's 

 fig. 7 in ri. XXXII., nor any plate like his fig. 8 in PI. XXXII. 



Textfig. 38. 



ranmjehia moseleyi : a, h — Lnrge wheels ; ■• — Small 

 wheel-like plate of dorsum ; d — Irregular plate around the 

 end-plate of lateral pedicel. ( x 200). 



