248 



where they lie in a dense layer. The rods in the tentacles (Fig. 

 44. 9) are more or less curved, their ends being usually enlarged 

 and often perforated. 



Eupatinapta acanthia is easily separated from multipora, as this 

 species is said to be wanting miliary granules in the body-wall. 



Labidoplax 0stergren 1898. 

 This genus is only represented in the collection at hand by 

 two small specimens from the Kei Islands. They are nicely pre- 

 served, and the examination shows them to be exceedingly interest- 

 ing and probably distinctly different from all the other species of 

 the genus. 



I have no doubt in referring them to Théels variety of incerta, 

 and in regarding this form as a valid species; but as there is only 

 the two specimens of the genus in this collection it is not the 

 place here to discuss the systematics of this interesting genus. 



Labidoplax variabilis (Théel). 



Synapta incerta var. variabilis. Théel. 1886. "Challenger" Holothurioidea 



II. pag. 14. Pl. I fig. 5. 

 Labidoplax dubia partim. Clark. 1908. The Apodous Holothurians. pag. 96. 

 The Kei Islands. 5° 31' S.— 131 0 26' E. 3. IV. 1922. 250 m. Sand. 

 2 specimens. 



The two specimens at hand measure 4,8 cm and 4,6 cm in 

 length by 0,2 cm in diameter. Their colour is white and the skin 

 is so thin and transparent that the longitudinal muscles and the 

 intestine may be seen through it. The one specimen is lacking 

 the anterior end. The other has twelve tentacles (Fig. 45. 1), each 

 supplied with four digits and 12 — 14 sensory cups, arranged in two 

 longitudinal rows. Only one of the tentacles has, as seen on the 

 figure, the "cups" more equally spread on the oral side of it. A 

 terminal digit as well as eye-spots are totally wanting. The cal- 

 careous ring (Fig. 45. 12-13) is very interesting in being sym- 

 metrical and in having only the three ventral radiais perforated 

 for the nerves. Muscular impressions are very distinct, and the 

 calcareous ring itself is thick and pure white. A cartilaginous ring 

 is totally wanting. There is only one polian vesicle. The stone- 

 canal can, due to contraction of the specimen, not be made out. 



The alimentary canal has no loop. Oesophagus is long and thin 



