in d. Naturgesch. d. nied. Thierc währ. d. Jahre 1876—1879. 489 



perfectly retractile, about twenty(?). The lateral ambiilacra of the 

 trivium with large pedicels, slightly retractile at their ends alone, 

 disposed in a single row all along eaoh side of the ventral surface, 

 and with another series of highly elongated. conical, rigid, not re- 

 tractile processes, placed externally and above the pedicels all along 

 each side of the body and directed straight outwards. The odd 

 ambulacrum naked. Bivium with processes, resembling those of the 

 trivium, disposed in a single row all along each of its ambulacra. 

 Processes formiug transverse rows, more or less distinct. Integu- 

 ment with crowded, irregularly rounded, perforated plates. 



Oneirophanta n. gen. Back highly convex ; ventral surface 

 flat. Mouth anterior, subventral; anus posterior, ventral. Tentacles 

 twenty, large and retractile at their ends alone. Tbe lateral ambu- 

 lacra of the trivium with large pedicels, slightly retractile at their 

 ends alone, disposed in a double row all along each side of the 

 ventral surface, and with another series of highly elongated, conical, 

 more or less flexible, not retractile processes, placed externally aud 

 above the pedicels all along each side of the body. The odd ambu- 

 lacrum with a few more or less rudimental pedicels. Bivium with 

 processes, resembling those of the trivium, disposed in a single row 

 all along each of its ambulacra. Processes not forming transverse 

 row^s or very indistinct ones. Integument with crowded, irregularly 

 rounded, perforated plates, often provided with minute processes. 



Orphnurgus n. gen. Back convex; ventral surface almost 

 flat. Mouth anterior, terminal, subventral; anus posterior, terminal, 

 slightly dorsal. Tentacles twenty. The lateral ambulacra of the 

 trivium with very large, not retractile pedicels, disposed in a single 

 row all along each side of the ventral surface, and with another 

 series of slender, very flexible, for the raost part apparently re- 

 tractile processes, placed above the pedicels all along each side of 

 the body. The odd ambulacrum naked. Bivium with a crowded 

 series of numerous processes, resembling those of the trivium, appa- 

 rently disposed in two rows all along each of its ambulacra. Inte- 

 gument with spicula of various forms, but destitute of wheels. 



Cryodora n. gen. Back highly convex; ventral surface al- 

 most flat. Mouth anterior, subventral; anus posterior, terminal, 

 subdorsal. Tentacles fifteen. The lateral ambulacra of the trivium 

 with large, slightly retractile pedicels, disposed in a single row all 

 along each side of the ventral surface. The odd ambulacrum naked. 

 Bivium with slender, flexible, not retractile processes, disposed in a 

 Single row all along each of its ambulacra. Integument spongy 

 without calcareous deposits. 



Laetmogone n. gen. Back highly convex; ventral surface 

 slightly so. Mouth anterior, terminal, subventral; anus posterior, 



