490 Leuckart: Bericht üb. d. wissenschaftlichen Leistungen 



terminal, slightly dorsal. Tentacles fifteen. The lateral ambulacra 

 of the trivium with large, not retractile, only a little contractile 

 pedicels, disposed in a Single row all along each side of the ven- 

 tral surface. The odd ambulacrum naked. Bivium with highly elon- 

 gated, flexible, cylindrical, not retractile processes, disposed in a 

 Single row all along each of its ambulacra. Integument with nume- 

 rous wheel-shaped plates and other calcareous deposits. 



Ilyodaemon n. gen. Back highly convex; ventral surface 

 nearly flat. Mouth anterior, almost ventral; anus posterior, ter- 

 minal, subdorsal. Tentacles fifteen. The lateral ambulacra of the 

 trivium with large, not retractile pedicels, apparently disposed in a 

 double row all along each side of the ventral surface. The odd 

 ambulacrum naked. Bivium with a crowded series of very nume- 

 rous, completely retractile, slender, rather long processes, disposed 

 in three or four irregulär close-set rows all along each of its 

 ambulacra. Integument with numerous, wheel-shaped plates and 

 dichotomously branched bodies. 



Achlyonice n. gen. Back highly convex; ventral surface flat 

 or almost concave. Mouth anterior, ventral; anus posterior, dorsal. 

 Tentacles twelve. The lateral ambulacra of the trivium with more 

 or less retractile pedicels, disposed in a single row all along each 

 side of the ventral surface. The odd ambulacrum naked. Bivium 

 with a few very soft and flexible processes in its anterior part alone. 

 Integument thick, spongy, destitute of calcareous deposits. 



Elpidia Theel (Char. emend.). Body ovate, more or less 

 elongated, sometimes cylindrical. Mouth anterior terminal or sub- 

 ventral, anus posterior, terminal, subventral or subdorsal. Tentacles 

 ten. The lateral ambulacra of the trivium with large, slightly re- 

 tractile pedicels, disposed in a single row along each side of the 

 ventral surface. The odd ambulacrum naked. Bivium with one or 

 a few pairs of often very elongated, not retractile processes on each 

 of its ambulacra, or with only a few more or less rudimental ones 

 in its anterior part. Integument with spicula of various shapes. 



M. Sars liefert in dem dritten Hefte der Fauna litto- 

 ralis Norvegiae (p. 58—65 PI. VII) eine eingehende Dar- 

 stellung von den Organisationsverhältnissen der von ihm 

 schon früher erwähnten Holothuria natans, die jetzt als eine Art 

 des Gen. Stichopus erkannt wird. Rücken und Bauch sind 

 durch Form und Bildung der Ambulacralanhänge scharf gegen 

 einander abgesetzt; das mediane Ambulacrum verkümmert. 



V. Marenzeller giebt in seinen „Beiträgen zurHolo- 

 thurienfauna des Mittelmeeres" (Verhandl. der zoolog.-bot. 

 Gesellsch. in Wien 1877 S. 117-122, Tab. V) eine Be- 



