On a New Species of Elasipoda from 

 Misaki. 

 By Prof. K. Mitsukuri- 



Science, College Imp. Univ. Tokyo. 



Ilyodœmon Ijimai, sp. n. 



This is by far the commonest of the holothurians found in the 

 deeper parts of the seas about the Misaki Marine Station, exceeding 

 greatly in number Lœtmogone violacea, Théel which is next to it in 

 abundance. 



The definition of the genus Ilyodœmon given by Théel* is as follows : — 

 Tentacles fifteen, rather large and non-retractile. The lateral 

 ambulacra of the ventral surface with large pedicels, apparently 

 disposed in a double row all along each side of that surface. The 

 odd ambulacrum naked. The dorsal surface with a crowded 

 series of very numerous, retractile, slender, rather long processes, 

 disposed in three or four irregular, close-set rows all along 

 each of its ambulacra. Integument with numerous wheels and 

 dichotomously branched bodies. 

 The present species falls in well with this definition, excepting a 

 single point. Its calcareous deposits wholly lach dichotomously branched 

 bodies. The specimens in my possession are quite numerous, and not 

 only do I fail to discover any dichotomously branched bodies in all the 

 preparations which show other kinds of calcareous deposits beautifully; 

 but there is not in any specimen any trace of larger and smaller white 

 spots visible to the naked eye, which are stated by Theel to be present 

 in I. viaculatus, and to be caused by those bodies. In view of this fact, it 



* Report on the Scientific Results of the Exploring Voyage of H. M. S. Challenger 

 1873-76, vol, IV, p. 84. 



