108 THE APODOUS HOLOTHURIANS 



anchors are about 500 /* in length and their plates only a little shorter; the 

 accessory plates are about 80 /* in diameter. There are only two polian ves- 

 sels and one stone-canal. 



PROTANKYRA PETEESI. 

 PLATE IV, FIGS. 15 AND 16. 



Synapta petersi Semper, 1868, p. 230. Calcareous particles, pi. xxxix, fig. 12. 

 Protankyra petersi Ostergren, 1898&. 



LENGTH. 130 mm. 



COLOR. Clear reddish. 



DISTRIBUTION. Eeported only from Amboina (Semper). 



EEMABKS. The type specimen of this interesting species still remains 

 unique. The curious grotesque anchors are accompanied by normal plates 

 perforated with numerous smooth holes. Nothing is known of the habits, hab- 

 itat, or anatomy. 



PROTANKYRA PSEUDO-DIGITATA. 



Synapta pseudo-digitata Semper, 1868, p. 9. Calcareous particles, pi. iv, fig. 12. 

 Synapta innominata Ludwig, 1874, p. 79. Calcareous particles, pi. vi, fig. 4. 

 Protankyra pseudo-digitata Ostergren, 18986. 

 Protankyra innominata Ostergren, 1898&. 



LENGTH. 60 mm. 



COLOR. Not recorded. 



DISTRIBUTION. Eeported from Bohol, Philippines, 27 m. (Semper) ; Philip- 

 pines (Ludwig) ; and Macasser (Sluiter). 



EEMARKS. Ludwig himself expressed the opinion that his species was pos- 

 sibly identical with Semper 's, and Lampert ('85) emphasizes the point. There 

 is little doubt that such is the case. Ludwig had only a fragment 10 mm. long 

 for his description and Semper had lost his only specimen when he wrote his 

 description. He says it was similar to Labidoplax digitata in appearance, 

 and Sluiter ( :01) tells us there are 12 tentacles, each with four digits. 



PROTANKYRA BANKENSIS. 



Synapta ~banlcensis Ludwig, 1874, p. 78. Calcareous particles, pi. vi, fig. 1. 

 Protankyra lankensis Ostergren, 18986. 



LENGTH. More than 75 mm.; only fragments known. 



COLOR. Whitish with a reddish tinge. 



DISTRIBUTION. Eeported only from Banka, Sunda Islands (Ludwig, 

 Theel). 



EEMARKS.- This species is certainly nearly related to the preceding and it 

 is an open question whether they are not identical. The differences in the cal- 

 careous particles are not beyond the range of individual diversity. 



