42 Pub. Piif/ef Sound Biol. Sta. Vol. 2. So. 33 



oped with no projections on either side, the radial plates with a central 

 perforation for the radial nerves (Figs. 37-39.) — Numerous, in the sand 

 at False Bay and at Argyle. 



Genus Chiridota 



Forms medium, about 10 to 12.5 cm. long, delicate, worm-like; skin 

 almost transparent; tentacles 12, with 3 to 10 digits on each side, the 

 terminal pair of digits longest; calcareous deposits in body wall in the form 

 of 6-spoked wheels, in tentacles in the form of bent rods. Usually found 

 in rather deep water. 



1. Chiridota laevis Fabricius. 



Holothuria pellucida Vahl; Trochinus palUdus Ayres ; Chiridota 

 tigillum Selenka ; Chiridota typica Selenka; Chiridota abyssicola von 

 Marenzeller. 



Forms medium in size, 12 cm. or more long; tentacles 12, with 5 

 digits on each side ; calcareous wheels forming papulae in rows on the 

 3 dorsal interradii, fewer scattered ones appearing on the ventral inter- 

 radii (Figs. 35, 36). Color pink. — Few, at 35 fathoms, near Olga. 



Genus Caudina 



Cylindrical, tapering to a tail; tube feet none; tentacles 15, cylin- 

 drical or with paired digits ; calcareous ring stout, radial pieces bifurcated 

 posteriorly ; calcareous deposits various. Burrowing in mud or sand, the 

 caudal tip exposed. 



1. Caudina obesacauda Clark. 



Body stout, about 7 cm. long and 25 mm. wide; tail not abruptly nar- 

 rowed, about a third the body-length; tentacles 15, each with t sharply- 

 pointed digits ; calcareous ring stout ; radial pieces with short slightly 

 bifurcated posterior prolongations (Fig. 45) ; calcareous deposits in form 

 of tables or enclosed cups. Color purplish brown. — Not numerous, at 35 

 fathoms, near Olga. 



BIBLIOGRAPHY 



Clark, H. L. 



1901. Echinoderms of Puget Sound. Proc. Boston Soc. Nat. Hist., 



Vol. 29, pp. 323-337. 

 1904. Echinoderms of the Woods Hole Region. Bull. U. S. Fish 



Comm., Vol. 22, pp. 545-576. 

 1907. Apodous Holothurians. Smithsonian Contrib. to Knowledge, 



Vol. 35. 

 1911. North Pacific Ophiurans in the collection of the United States 



National Museum. Proc. U. S. National Museum, Bull. 75. 



