174 



it is thin and translucent. The perforations through its posterior 

 margin are so large that they reach the intransparent part, for 

 which reason the posterior part of the cartilaginous ring is reduced 

 to "tentacle-canals" (cf. the description of Synapta picta (= Synap- 

 tula hydriformis) by Théel in "the Challenger Holothurians" II 

 pag. 10). The calcareous ring (Fig. 20. 10) is in the specimens 

 from Amboina pure white, and in the other specimens, as said, 

 tinged with black. The radial pieces are perforated for the nerves, 

 and the muscular impressions are faint. There are in all the spec- 

 imens ca. 15 polian vesicles and a single stone-canal. The gonads 

 are branched and the intestine has a loop. On the mesenteries 

 there are ciliated funnels of the usual size and shape. 



The anchors and anchor-plates from the two ends of body are 

 different, and in the posterior end they are of two different sizes. 

 The large anchors in the posterior end (Fig. 20. 3) measure ca. 

 270 jn in length and 170 jtv in width. The small anchors (Fig. 20. 6) 

 measure ca. 210 p x 140 ^ and those from the anterior end of body 

 (Fig. 20. 1) measure ca. 240 /u x 140 (ju. The anchors are all of the 

 same shape with the stock finely dented and with minute knobs on 

 the vertex. 



The anchor-plates from the posterior end of body (Fig. 20. 4 & 7) 

 measure ca. 200 t a x 160 [i and 140 [ju x 120 ja, and the normal 

 plates from the anterior end (Fig. 20. 2) ca. 160 fi x 130 /n. In 

 the anterior end there are some few larger plates, which are of 

 the same size as the large plates in the posterior end, ca. 200 ja x 

 160 ju. All the anchor-plates are of the same shape with the articular 

 holes smooth and with the bridges serrate. In the posterior end of 

 the plates there are 5 — 7 small holes. 



The miliary granules (Fig. 20. 8) are ca. 20 fi large rosettes, 

 which are found all over the skin arranged into long heaps or 

 rather stripes, which, as Sluiter writes, lends the purple skin its 

 peculiar colour. 



Synaptula jolensis n. sp. 



Off Jolo. 19. III. 1914. Ca. 25 fms. Sand, coral. 1 specimen. 



The specimen at hand measures 5 cm in length and 0,8 cm 

 in diameter. The colour is pale red with some irregular white 

 stripes. There are 13 tentacles of the same colour as the body, 



