306 



to represent several different valid species. Even the specimens 

 here referred to Ch. variabilis Semper, as well as S e m p e r's dif- 

 ferent specimens of this species, probably represent different forms, 

 which may be characterized and separated by the shape of the cal- 

 careous ring and the serration of the ends of the curved rods in 

 the skin. 



The genus Polycheira is at any rate one of the least known 

 genera of the Synaptidae, and without any doubt the classificatory 

 problems connected with it are very interesting and might well 

 deserve being taken up for a closer investigation on a better ma- 

 terial. The present collection, does not allow a detailed study 

 neither of the calcareous deposits nor of the finer, anatomical details. 

 For the present we may distinguish between the following three 

 species: variabilis Semper, vitiensis Semper and echinata Heding. 

 According to Lud wig's Revision der Mertens-Brandt'schen 

 Holothurien pag. 573- — 579, Brandt's species Chirodota rufescens 

 is the same as S e m p e r's variabilis, for which reason we may use 

 the eldest name, though only Sem pe r's description is tolerably 

 usable. 



Key to the species of Polycheira. 



1. Ciliated funnels ca. 100 /< in length 2 



Ciliated funnels ca. 350 p in length vitiensis 



2. Miliary granules 60 — 100 ^ long, more or less irregularly C-shaped. 

 Oval bodies present in the longitudinal muscles. Rods in tentacles 

 usually more than 150 /tt and often with branched ends. Ciliated funnels 



in large distinctly stalked clusters with more than 15 funnels rufescens 

 Miliary granules 120—160 l l long, slightly bent rods with spiny ends. 

 Oval bodies in longitudinal muscles wanting. Rods in tentacles not 

 more than 110 fi long, usually unbranched. Ciliated funnels in small 

 short-stalked clusters with only 3 — 5 funnels in each echinata 



Polycheira rufescens (Brandt). 

 Chiridota rufescens. Brandt. 1835. Prodromus. . . . pag. 59. 



„ variabilis. Semper. 1858. Die Holothurien. pag. 20, 231 & 

 267. Pl. V fig. 6, 7, 9, 11, 19, Pl. VIII fig. 5—6 and 

 Pl. XXXIX fig. 15. 

 „ rufescens. Ludwig. 1881 . Revision der Mertens-Brandt'schen 

 Holothurien. pag. 579. 

 Polycheira rufescens. Clark. 1908. The Apodous Holothurians. pag. 120. 



Ohshima. 1813. Synaptiden von Misaki. p.258fig.9. 

 „ „ Ohshima. 1914. The Synaptidae of Japan, pag. 475. 



