ACTiNOPnnoiTs holothurioidea. 55 



individuals tliose rings forniod wliito patches, wliicli were most 

 conspicuous aioiiLC the sides and around the cloaca, sometimes 

 tm'ning into white the prominent color of tln'se regions or even of 

 the whole dorsum. In otlier individnals, tlie rings were conlined 

 to a few papillae along the si<les or around the cloaca. 



Tentacles 25 — 27 (two individuals from (.)gasawara Is. had 

 25 and two others 27). Another smaller individual from tlic same 

 locality had only 20. AVhether this was duo to some tentacles 

 having been lost, or to the young individual not having a full 

 complement, could not be ascertained. 



Calcareous deposits in the dorsal perisome : (i) numerous 

 slender elongate rods with short, mostly simi)Ie, occasionally 

 slightly branched processes along their sides, and with a tendency 

 to divide dichotomously at the ends (textfig. 11 7). Length 0.04 

 — 0.13 mm., breadth 0.004 — 0.007 mm. (ii) Incomiilete rosettes, 

 0.034 — 0.02 mm. across (h). In the ventral ])erisome : (i) Elongate 

 rods, in genei'al shorter but thicker than those in the dorsal peri- 

 some. In some the margin is smooth ( / ), in others it is beset 

 with line close-set processes, making it serrate (//) ; in still 

 others, there are along the margin well marked pi'ocesses, some of 

 whicli may even be branched (7). The ends of the rods are almost 

 always more or less rough, and sometimes bilid. The two ends 

 are very often different. There ai'e all stages of gradation 

 between these various forms. Si/.e vai'ying beiween 0.]2x 

 n.DlS mm. and 0.0 1 1 x 0.012 mm. (ii) Oval grains, sometimes 

 regularly oval (<■], sometimes moi'c oi' less irregular or biseuit- 

 shape(], being jiinched in llio middle (d) ; sometimes aggre- 

 gations of small lobes, approaching the rosettes {(■). The longest 

 oval grains and shortest rods can nol lie distiiiguishetl. Length 

 and breadth "i.n 1 xO,02— 0.02 x n.Ol 1 mm. (iii) Ho.gcttes (a), much 



