319 



Tœniogyrus clavus is, although nearly related to keiensis and 

 cidaridis, easily recognized by the shape of the calcareous ring, the 

 hooks and the tentacle-spicules. Furthermore the unbranched gonads 

 may be a valid character for separating this species from the others. 



Scoliodota Clark. 



Scoliodota Clark. 1908. The Apodous Holothurians. pag. 125. 

 Trochodota Clark. 1921. The Echinoderms from Torres Strait, pag. 164. 



Genotype: Scoliodota théelii Heding. 



Diagnosis: Tentacles ten, peltated, digitate. Wheels wanting; 

 calcareous deposits in the skin sigmoid bodies only. In the ten- 

 tacles rods may occur. Calcareous ring bilaterally symmetrical. 

 Polian vesicle and stone-canal single. 



Remarks: The genus Scoliodota was established by Clark in 

 1908 with the species Chiridota japonica v. Marenzeller as the 

 genotype. This species is rather unsatisfactorily described, and the 

 real genotype may for this reason be the specimens which Théel 

 in 1886 referred to v. M a r e n z e 1 1 e r's species. In 1913 O fi- 

 sh ima showed that v. Marenzeller's species is a Trochodota, 

 for which reason Clark in 1921 abandoned the genus, without 

 taking into consideration the Australian specimens, described by 

 Théel. The specimens from Port Jackson at hand leave no doubt 

 that they represent the same species as the specimens described 

 by Théel in 1886, and as they are generically different from 

 Trochodota, I have no doubt in referring them to Clark's genus 

 Scoliodota. Scoliodota is then a monotypic genus, for the present 

 only known from Australia. 



Scoliodota théelii n. sp. 



Chiridota japonica. Théel. 1886. "Challenger" Holothurioidea II. pag. 17, 

 Pl. II fig. 3. 



Scoliodota japonica. Clark. 1908. The Apodous Holothurians. pag. 125, 

 Pl. VII fig. 5. 



Port Jackson. 8. X. 14. 3—5 fms. 2 specimens (+ several fragments). 



The real length of this species cannot be ascertained, as none 

 of the specimens at hand are complete, but it may prove to be ca. 

 10 — 15 cm. The colour of the skin is, in alcohol, pale grey, but 

 the specimens are, especially in the anterior end, covered by a dense 



