THE APODOUS HOLOTHURIANS 117 



EEMAEKS. Although this species is apparently well characterized, it is 

 difficult to understand just what form the "schnallenformige" particles have, 

 and in view of the results of Ludwig's ('83) reexamination of the material on 

 which ITaacke based his numerous (14) new species, we may be pardoned if 

 we are very skeptical regarding this Chiridota, which Ludwig was unable to 

 examine. 



CHIRTDOTA REGALIS. 

 Chiridota regalis Clark (antea, p. 28). 



LENGTH. Up to 200 mm., with a diameter of about 6 mm. 



COLOR. More or less deep, royal purple, deepest anteriorly; more grayish 

 posteriorly. 



DISTRIBUTION. Coast of Japan, 198-300 m. (Clark). 



REMARKS. Although quite nearly related to uniserialis and also to discolor, 

 which it approaches in size and general appearance, this seems to be a well- 

 marked species. 



CHIRIDOTA UNISERIALIS. 

 Chiridota uniserialis Fisher, 1907, p. 733 ; pi. LXXXI, fig. 4, and pi. LXXXI, figs. 5, 5a-c. 



LENGTH. 150 mm., with diameter of 7-9 mm. 



COLOR. Dark purple or pale lilac. 



DISTRIBUTION. North of Molokai, Hawaiian Islands, 590-745 m. (Fisher). 



REMARKS. This species appears to be very close to the preceding, but the 

 difference in the size, form, and distribution of the C-shaped rods is quite strik- 

 ing. Fisher notes well-developed retractor muscles in uniserialis, but I found 

 none in regalis. The wheel-papillae in regalis are often very numerous (70-80 

 or more), of very variable size, and most numerous anteriorly, where they may 

 occur in the lateral interambulacra, while in uniserialis they are 9-50 in num- 

 ber, of conspicuous size, confined strictly to the mid-dorsal interambulacrum, 

 and often most numerous posteriorly. 



CHIRIDOTA RIGIDA. 

 PLATES II, FIG. 3 ; VII, FIGS. 26-29. 



Chirodota rigida Semper, 1868, p. 18 ; pi. in, fig. 3. Calcareous particles, pi. v, figs. 



3 and 13. 



Chirodota liberata Sluiter, 1888, p. 212. Calcareous particles, pi. n, fig. 44. 

 Chirodota amboinensis Ludwig, 1888, p. 819. 

 Chiridota rigida Ludwig, 1892&. 

 Chiridota liberata Ludwig, 1892&. 

 Chiridota amboinensis Ludwig, 18926. 

 Chiridota hawaiiensis Fisher, 1907, p. 731 ; pi. LXXXI, fig. 5, and pi. LXXXII, figs. 3, 



3a-e. 

 LENGTH. 25-75 mm. 



