126 THE APODOUS HOLOTHUEIANS 



This is another monotypic genus. Its relationship with Chiridota is per- 

 fectly obvious, but wheels appear to ba consistently wanting. The calcareous 

 particles are very small, only about 60 /* in length, and closely resemble the 

 C-shaped rods of Chiridota rotifer a. 



TOXODOBA FERRUGINEA. 



Toxodora ferruginea Verrill, 1882, p. 220. 

 Chirodota ferruginea Theel, 1886a. 

 Anapia ferruginea Ludwig, 1892&. 

 Sigmodota ferruginea Ostergren, 1898&. 



LENGTH. 30 mm. or more, with a diameter of 5-10 mm. 



COLOR. Reddish brown, from the minute pigment-cells with which the skin 

 is thickly filled. 



DISTRIBUTION. Reported only from several stations south of Nantucket and 

 Marthas Vineyard, in 140-280 m. (Verrill). 



REMARKS. Thanks to the kindness of Professor Verrill and Miss Rathbun, 

 I have had the opportunity of examining specimens of this interesting species. I 

 find that the calcareous deposits are very much like the C-shaped particles 

 of some species of Chiridota. But there is no indication that wheels are, or ever 

 have been, present, and the species therefore cannot be placed in that genus. 



ACHIRIDOTA, gen. nov. 



( privative + chlridnta; \. e., not chirirlota.) 



Tentacles peltato-digitate, 12. Digits small and rather numerous (6-8 pairs). 



Deposits entirely wanting. Polian vessel single, large. Calcareous ring well- 

 developed. 



This genus seems to be required for the following unique species, which 

 bears the same relation to Chiridota that Anapta does to Leptosynapta and that 

 Dactylapta does to Protankyra. 



ACHIRIDOTA INERMIS. 

 Anapta inermis Fisher, 1907, p. 730; pi. LXXIII, fig. 2, and pi. LXXXIL fig. 1. 



LENGTH. About 100 mm.; greatest diameter, 14-20 mm. 



COLOR. Bleached grayish, profusely covered with small reddish-brown or 

 yellowish-brown spots, most abundant anteriorly. 



DISTRIBUTION. Hawaiian Islands, 466-772 m. (Fisher). 



REMARKS. This singular species, of which Fisher had eleven specimens 

 from seven stations, is very much like Chiridota in general appearance, but 

 the single polian vessel and the entire absence of deposits separate it distinctly 

 from that genus. 



