The Synaptidœ of Japan. 



By 



Hiroshi Ohsliima, Rigakushi. 



In his "List of Holothurians known to occur in Japan ,M> the 

 late Prof. K. Mitsukuri gave seven species of Synapticls, founded on 

 the reports of v. Marenzeller and Théel. They are : i) Synapta in- 

 certa, var. variabilis Théel [ = Labidoplax dubia (Semper)] ; 2) 5. 

 ooplax v. Marenzeller [ = Leptosynapta ooplax]; 3) 5. distincta v. 

 Marenzeller \_ = Protankyra bidentata (Woodward et Barrett)] ; 4) S. 

 autopista v. Marenzeller \=Protankyra autopista] ; 5) S. aculeata 

 Théel \_=Protankyra aculeata] ; 6) Chiridota japonica v. Marenzeller 

 [ = Scoliodota japonica]; and 7) Ch. rtifescens Brandt [ = Polyc/ieira 

 rufescens]. 



Since that time four more species have been reported from Japan 

 a nd adjacent localities, viz., 1) Myriotrochus minutus Ostergren ; 2) 

 Atiapta ludwigi Britten ; 3) A. amurensis Britten ; and 4) Chiridota 

 regalis Clark. 



To the above list of eleven Synaptid species, I have added seven 

 more, besides an indeterminable form, in my report on the Holothurians 

 collected by the " Albatross " off the coasts of Japan, which report 

 will shortly be published in another place. Further, from examination 

 of the Synaptida; in the Science College Museum, I have come to 

 know that there still existed five more species, including one new 

 species, to be added to the list, thus bringing the number of Synaptid 

 species occurring in the waters around Japan, up to twenty-three 

 altogether. 



I here propose to present brief notes on all these Synaptids, to 

 supplement in a way the late Professor Mitsukuri's excellent mono- 



1) Zoological Magazine, vol. VIII, no. 97, 1896. 



