277 



Subfamily II. Ghiridotinae. 



0stergren. 1898. Das System der Synaptiden. pag. 117. 



Clark. 1908. The Apodous Holothurians. pag. 112. 



Clark. 1921. The Echinoderms of the Torres Strait, pag. 163. 



The subfamily Chiridotinae was established in 1898 by 0ster- 

 gren for the two genera Sigmodota Studer and Chiridota Eschscholtz, 

 and it is maintained by Clark in "The Apod. Holoth." 1908. In 

 this work Clark totally abandons the genus Sigmodota and only 

 maintains the name Chiridota for the 12-tentacled species. For the 

 18-tentacled species he establishes the new genus Polycheira. The 

 group "Sigmodota" is divided into four different genera: Tœniogyrus 

 Semper, Trochodota Ludwig, Scoliodota Clark and Toxodora Verrill. 

 For Fisher's species Anapta inermis, which may be regarded as 

 a Chiridotid, Clark furthermore establishes a separate genus Achiri- 

 dota. These five genera are based only on differences in the cal- 

 careous deposits and in the number of the tentacles, and appear to 

 be rather well defined. 



In spite of this Dendy, who by his studies of the New Zealand 

 species of the Chiridotinae came to the conclusion that differences 

 in the shape of the calcareous deposits are not usable as generic 

 characters, in 1909 rejects all the genera and refers all the species 

 to Chiridota. Besides Chiridota he has only one genus Rhabdomol- 

 gus Keferstein, which he regards as a Chiridotid, concluding from 

 his new species Rhabdomolgus novae-zealandiae. As Rhabdomolgus 

 cannot be regarded as a Chiridotid, Becher in 1909 proposes the 

 name Kolostoneura for Dendy's species, which may without any 

 doubt be regarded as a Chiridotid. There is, as far as I can see, 

 no reason for following Dendy in rejecting the different genera of 

 the Chiridotinae, and I therefore fully agree with Clark in main- 

 taining them. In the report on the Echinoderms from the Torres 

 Strait, Clark discusses in an excellent way these questions, and 

 gives good reasons for maintaining the different genera. Only Scolio- 

 dota is here abandoned by Clark. The type of that genus was 

 Chiridota japonica v. Marenzeller, which, according to v. Maren- 

 zell er and Thé el, has no wheels among the sigmoid bodies. Now 

 Ohshima in 1912 has shown that in the Japanese specimens some 

 few wheels may be found, for which reason they are better referred 

 to the genus Trochodota, and as to geminifera Dendy, Clark sup 



