62 THE VOYAGE OF H.M.S. CHALLENGER. 



Tabular View of the genera of the Family Deimatid^. 



I. Integument mostly rather hard, strengthened by numerous perforated calcareous 



plates, often crowded and forming a skeleton; tentacles twenty. 



A. Tentacles small, retractile. Pedicels of the ventral lateral ambulacra in a 



single row, ........ Gen. I. Deima. 



B. Tentacles large, not retractile. Pedicels of the ventral lateral ambulacra 



in a double row, ....... Gen. II. Oneirophanta. 



II. Integument pliable, strengthened by scattered spinose spicula ; tentacles twenty, . Gen. III. Orphnurgus. 



III. Integument very pliable, containing wheels along with spicula, cruciform bodies, 



or dichotomously branched deposits. 



A. Tentacles twenty; odd ambulacrum with a double row of pedicels, . Gen. IV. Pannychia. 



B. Tentacles fifteen ; odd ambulacrum naked. 



a. Dorsal processes very long, disposed in a single row along each 



ambulacrum, ....... Gen. V. Lmtmogone. 



b. Dorsal processes shorter, disposed in several rows along each ambula- 



crum, ........ Gen. VI. llyodozmon. 



Oneirophanta, Thdel. 



Oneirophanta, Theel, Preliminary Report on the Holothurida?, p. 6. 

 Tentacles twenty, large, and not capable of being retracted within the mouth. The 

 lateral ambulacra of the ventral surface with large pedicels disposed in a double row all 

 along each side of that surface, and with another series of very elongated, conical, more 

 or less flexible, non-retractile processes, placed externally and above the pedicels all along 

 each side of the body. The odd ambulacrum with a few more or less rudimentary 

 pedicels. The dorsal surface with processes, resembbng those of the ventral lateral 

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

 more or less crowded, irregularly rounded, perforated plates, sometimes forming a rather 

 hard skeleton. 



Ondroplianta mutabilis, Theel (PI. XXI. fig. 2 ; and PI. XXII. ). 



Oneirophanta mutabilis, Theel, Preliminary Report on the Holothuridre, pp. 6, 7. 

 Body elongated, of almost ecpial breadth throughout, more than twice as long as broad. 

 Mouth anterior, subventral. Anus posterior, ventral. Tentacles of ecpial or unequal size ; 

 their terminal part with six to eight small unbranched processes. Pedicels varying greatly 

 in number from about fifty-four in all — twenty-eight along the left side and twenty-six 

 along the right — to only eleven along each side or even less. The odd ambulacrum 

 with two to nine small pedicels. Processes of each of the lateral ambulacra of the ventral 

 surface varying in number from about seventeen to seven or less. Processes of each of 

 the dorsal ambulacra varying from seventeen or nineteen to seven or less. The length of 

 the processes varying greatly, some being almost rudimentary, others as long as the breadth 



