311 



two of which are new to sience. Thus we know for the present 

 six different species of this genus: 



1856. australianus (Stimpson). 



1874. contortus (Ludwig). 



1915. cidaridis Ohshima. 



1921. dubius Clark. 



1928. keiensis n. sp. 



1928. clavus n. sp. 

 These species are in several characters rather alike, but they 

 may be separated as follows : 



1. Tentacles 12 2 



Tentacles 10 3 



2. Polian vesicles 6 or 7. Wheels 42 — 130/^ in diameter. Inrolled end of 

 sigmoid bodies divided into a few short, pointed branches . . contortus 

 Polian vesicles 10. Wheels 90— 195 l l in diameter. Inrolled end of sig- 

 moid bodies unbranched dubius 



3. Polian vesicles 12 keiensis 



Polian vesicle single 4 



4. Sigmoid bodies in groups australianus 



Sigmoid bodies not in groups 5 



5. Radiais faintly furrowed on exterior side. No conspicuous projection 

 on the anterior margin. Tentacle-rods small. Gonads 2 — 3 times 



bran ched cidaridis 



Radiais not furrowed on exterior side. A large square projection on the 

 anterior margin. Tentacle-rods large. Gonads unbranched .... clavus 



Tœniogyrus contortus (Ludwig). 



Chirodota contorta. Ludwig. 1874. Beiträge zur Kenntniss der Holo- 



thurien. pag. 80, Pl. VI fig. 6. 

 Chirodota contorta. Ludwig. 1898. Holothurien der Hamburger-Magel- 

 haensischen Sammelreise, pag. 73, Pl. Ill fig. 37 — 42. 

 Tœniogyrus contortus. Clark. 1908. The Apodous Holothurians. pag. 122. 

 Pl. VII fig. 8—13. 

 „ „ Clark. 1921. The Echinoderms from the Torres 



Strait, pag. 165. 

 Kerguelen. 20 — 60 fms. Prof. Thompson. 



The single specimen available is ca. 3 cm long and its colour 

 is in spirit pale brown. It has 12 much contracted tentacles, but 

 the number of digits cannot be ascertained. The calcareous ring 

 consists of twelve pieces, which are, as far as seen on the poorly 

 preserved specimen, of quite the same shape (Fig. 66. 2), the radiais 



