251 



Though they do not throw much light on the systematics of this 

 large and perplexing genus, the specimens at hand afford a desirable 

 opportunity for studying more in details the four species: 



Synapta bidentata, Woodward & Barrett. 

 Synapta pseudo-digitata Semper. 

 Synapta autopista v. Marenzeller. 

 Synapta asymmetrica Ludwig. 



These studies show that bidentata is a well characterized species, 

 and that it has, as well as pseudo-digitata, two different sorts of an- 

 chors and anchor-plates in the posterior end of body. Furthermore 

 there can be no doubt that Synapta distincta v. Marenzeller is 

 synonymous with it. 



In asymmetrica there are found branched, ciliated funnels, and 

 the comparison of the funnels in these four species with those found 

 in the four new species, indicates that the ciliated funnels are of 

 the greatest value as specific characters in Protankyra. 



In "The Apod. Holoth." Clark refers 25 different species to this 

 genus, saying that: "Scepticism as to the validity of some of these 

 species is bound to arise", and since that time six new species have 

 been described. In "Echinoderms from New Zealand and the Auck- 

 land-Campbell Islands" Dr. Mortensen has described some spec- 

 imens of uncinata Hutton, which according to Dr. Mortensen 

 may be regarded as a valid species. Thus we may for the present 

 distinguish the following 32 species: 



1858. bidentata. Woodward & Barrett: On the genus Synapta. pag. 365, 



Pl. XIV fig. 23—25. 

 1868. pseudo-digitata. Semper: Die Holothurien. pag. 9, Pl. IV fig. 12. 



similis „ „ pag. 10, Pl. Ill fig. 2, 



Pl. IV fig. 14. 



petersi „ „ pag. 230, Pl. XXXIX f. 12. 



1874. asymmetrica. Ludwig: Beiträge zur Kenntniss der Holothurien. 

 pag. 78, Pl. VI fig. 2. 

 bankensis. Ludwig: Beiträge zur Kenntniss der Holothurien. 

 pag. 78, Pl. VI fig. 1. 

 1881. autopista. v. Marenzeller: Neue Holothurien aus Japan und 

 China, pag. 123, Pl. IV fig. 3. 

 benedeni. Ludwig: Ueber eine lebendiggebärende Synaptide. 

 pag. 55, PI. III fig. 19—20. 

 1885. brychia. Verrill: Results of the Expeditions made by the 



steamer "Albatross", pag. 539. 



