THE APODOUS HOLOTHURIANS 109 



PROTANKYRA SIMILIS. 

 PLATE IT, FIG. 2. 



Synapta similis Semper, 1868, p. 10; pi. in, fig. 2. Calcareous particles, pi. iv, 



fig. 14. 

 Protankyra similis Ostergren, 1898&. 



LENGTH. 60-100 mm. 



COLOR. Semper gives the color as "transparent reddish," but the colored 

 figure is pale fawn color with purplish tints. 



DISTRIBUTION. Eeported only from Bohol, Philippines (Semper). 



REMARKS. The anchors and plates of this species are very much like the 

 large ones of P. pseudo-digitata, and the accessory calcareous bodies also re- 

 semble those of that species. There is a single stone-canal and one or two 

 polian vessels. Semper says this is one of the commonest and most interesting 

 of the Philippine synaptids, living in the mud of brackish, mangrove swamps. 

 It is well known to the natives and is called "dapan-dapan" in Visayan. It 

 should perhaps be made the type of a distinct genus. 



ANAPTA Semper, 1868. 



Tentacles pinnate, 12. Digits 2-6 on each side and a long terminal one. 

 Cartilaginous ring wanting. Polian vessels several (5-7). Stone-canal single. 

 Anchors, perforated plates, wheels, and sigmoid bodies entirely wanting, the 

 only calcareous particles in the skin being small oval or ellipsoidal bodies, and 

 even these may be wanting. 



This small group is closely related to Leptosynapta, but is of course easily 

 distinguished therefrom py the entire absence of anchors. Ostergren ( '98fe) con- 

 siders that Sluiter's ('88) species subtilis is based on an abnormal individual, 

 and he accordingly omits it; but since Sluiter especially states that the animal 

 was examined when fresh, and consequently its peculiar characters cannot be 

 due to decalcification, there is no reason to doubt its authenticity. Were it a 

 regenerating synaptid, the calcareous ring would be normal and there would 

 be some indications of calcareous bodies. Ludwig ('92b) proposes to in- 

 clude in Anapta, Toxodora ferruginea Verrill and Scoliodota japonica (v. 

 Marenzeller), but the affinities of these two species seem to be so clearly with 

 the Chiridotinae that it would be very misleading to place them here. 



KEY TO THE SPECIES OF ANAPTA. 



A. Calcareous particles present in the skin, longitudinal muscles or tentacles. 



Size large (up to 190 mm.) ; calcareous bodies scattered everywhere in the skin. 



GRAOILIS 



Size small (under 100 mm.) ; calcareous bodies confined mainly to radii or longitudinal 



muscles and tentacles; those of latter often slightly branched at the end. . . .FALLAX 



A A. Calcareous particles wanting SUBTILIS 



