253 



Synapta distincta v. M a r e n z e 1 1 e r. 1881. Neue Holothurien von Japan 

 und China, pag. 123, Pl. IV fig. 2. 

 T h é e 1. 1 886. The "Challenger" Holothurians II. pag. 1 1 . 

 Pl. I fig. 8. 



Protankyra bidentata. 0stergren. 1898. Das System der Synaptiden. 

 pag. 117. 



Protankyra distincta. 0stergren. 1898. Op. cit. pag. 117. 

 Protankyra bidentata. Clark. 1908. The Apodous Holothurians. pag. 102, 

 Pl. V fig. 30. 



„ „ Ohshima. 1913. Synaptiden von Misaki. pag. 



256—58 & 261, Pl. VI fig. 7—8. 

 „ „ Ohshi ma. 1914. The Synaptidae of Japan, pag.471. 



Misaki. 29. IV. 1914. The shore. 35 specimens. 



The specimens at hand measure up to 15 cm in length by 

 1 — 1,5 cm in diameter. Their colour is in alcohol pale yellow. 

 The body-wall is rather thin and semitransparent, but so stiff that 

 the specimens may stand on their end in the jar. There are twelve 

 ca. 2 mm long tentacles, each with four digits and 1 — 2 sensory 

 cups. The digits are of equal length, measuring ca. 1 mm. On the 

 oral disk there are 12 eye-spots. The radial pieces of the calcareous 

 ring are perforated for the nerves and the muscular impressions are 

 distinct. A cartilaginous ring is wanting. There are 2 — 5 polian 

 vesicles and a single stone-canal. The gonads are several times 

 branched and rather voluminous. They measure ca. 10 cm in length. 

 The oesophagus is distinctly different from the folded intestine, being 

 straight and very muscular. It measures ca. 5 cm. The intestine 

 has a large loop. The ciliated funnels (Fig. 46. 1 1) are stalked and 

 fan-shaped. They are found on and at the base of the mesenteries, 

 and are not united into clusters. Their length is ca. 150 ^. 



The calcareous deposits are distinctly different in the two ends 

 of the body, and in the posterior end there are two different sorts 

 of anchors and plates. The largest anchors (Fig. 46. 1-3) and their 

 corresponding plates are only found in the interambulacra. They 

 measure ca. 450 [i in length and 260 // in width. Their arms are 

 distinctly serrate and the vertex is smooth and convex. The arms 

 are usually of equal length, but may vary somewhat, the anchors 

 then being asymmetrical (Fig. 46. 3). The large anchor-plates (Fig. 

 47. 1) are of very nearly the same width, but they vary from 

 300 — 400 fi in length, the anterior end being more or less reduced. 

 The holes are all smooth, but the exterior surface of the plates 



