322 



rather peculiar rods (Fig. 69. 1 1). They are of the same size as the 

 sigmoid bodies and are all of very nearly the same size. 



Scoliodota théelii is in several respects rather like Trochodota 

 dendyi, but it differs distinctly from that species in the shape of 

 the calcareous ring, the tentacle-rods and the ciliated funnels. 



Note. It may be desirable to add this little note, containing 

 some biological observations made by Dr. Mortensen on various 

 of the Synaptids collected during his voyages. 



Opheodesoma grisea (Semper). This species was found in con- 

 siderable numbers thrown up on the beach in Pearl Harbour, near 

 Honolulu. Although almost completely dried up they were still 

 alive, and it was very remarkable to see the dry skin, which had 

 almost the appearance of a piece of black paper, gradually assum- 

 ing its normal appearance and consistence as the rising water 

 reached them. It is evident that this Synaptid can stand a fairly 

 long exposure to the direct radiation of the sun, apparently more 

 so than any other Holothurian. However, those specimens which 

 were thrown higher up on the beach and had been completely 

 dried up, were definitely dead. Direct experiments as to the re- 

 sistance of this species aginst exsiccation might well lead to in- 

 teresting results. 



Patinapta ooplax (v. Marenzeller). On the little island of Sa- 

 malona, off Makassar, this species was found in good numbers in 

 the coarse coral sand of the beach, in a place rather exposed to 

 the surf. The animals were living entirely buried in sand, digging 

 like earthworms and eating their way through the sand, their ali- 

 mentary canal being completely filled therewith. They seem thus 

 to feed on the detritus and the microorganisms which may be 

 living in the sand — a rather meagre diet, anyhow. They were 

 rather tough in spite of the skin being quite thin and transparent, 

 so that they would not break when being grasped by one end 

 and hauled out of the sand. 



Polycheira mfescens (Brandt). On the little island of Koh Lorn, 

 off the W. coast of Koh Chang, in the Gulf of Siam, this nearly 

 black Synaptid was found in considerable numbers under stones 

 on a sandy beach; about a score of specimens would be found 



