REPORT ON THE HOLOTHURIOIDEA. 161 



Lcetmogone violacea, The'el. 

 Fig. 20. Side view of a large wheel ; diameter about 0'2 mm. 

 „ 21. Cruciform bodies from 0"072 mm. to 0"2 mm. in diameter. 

 „ 22. Spicula from the pedicels. 

 „ 23. Spicula from the tentacles. 

 „ 24. Spiculum from the ventral perisoma ; length about 0"16 mm. 



Kolga nana, Theel. 

 „ 25. Otolith ; length about 0*028 mm. 



Benthodytes abyssicola, n. sp. 



,, 26. The sheath of a four-armed deposit, the calcareous substances being dissolved ; 



the arms about - 5 mm. long. 

 „ 27. Minute bodies within the integument. 



PLATE XXXVII. 



Elpidia willemoesi, n. sp. 

 Fig. 1. One of the five pieces or spicula which compose the calcareous ring. 



Parelpidia elongata, Theel. 

 „ 2. One of the five pieces or rather spicula which compose the calcareous ring. 



Deima fastosum, Theel. 

 „ 3. A portion of the calcareous ring, a, notch for the passage of the ambulacral 

 nerves, &c. 



Oneirophanta mutabilis, Theel. 

 „ 4. Side view of a portion of the calcareous ring, a, radial piece ; b, interradial 

 pieces ; x, notch for the ambulacral nerves, &c. 



Lcetmogone loyville-thomsoni, Theel. 

 5. Genital process with four tops. 



Peniagone wyvillii, n. sp. 

 „ 6. A piece of the dorsal body-wall seen from the inner side, showing the foremost 

 parts of the dorsal ambulacra and the terminations of the madreporic 

 canal and the reproductive organs, a, perisoma near the tentacles ; b, that 

 part of the perisoma which is more distant from the tentacles ; c, dorsal 

 nerve stems ; d, dorsal radial ambulacral vessels and dorsal longitudinal 

 muscular bands ; e, common efferent duct of the reproductive organs, 

 which divides into two canals, each of which gives off a number of long 



(ZOOL. CHALL. EXP. — PART XIII. — 1881.) N 21 



