NO. 3 DEICHMANN : HOLOTHURIOIDEA ; PART I, DENDROCHIROTA 1 1 3 



tains that the calcareous ring lacks posterior prolongations, and he does 

 not mention the difference in the form of the dorsal and ventral append- 

 ages and the striking black and white coloration. The calcareous ring 

 does, however, superficially look as if it lacks posterior prolongations, and 

 the differences between the dorsal and ventral appendages and the color- 

 ing may quite well be less pronounced in younger individuals. On the 

 other hand, the description of the spicules shows no discrepancies, and the 

 present species is the only "Thyone"-Uke form with such spicules as those 

 described by Ludwig. Also it speaks in favor of the identification that it 

 is usually found in the same localities as Neothyone gibber. 



Neothyone panaTnensis is easily recognized on account of its color and 

 the arrangements of its feet. Also the spicules are very striking. The bas- 

 kets seem to be retained throughout the animal's life and are numerous in 

 all preparations, while the large, smooth supporting plates from the ven- 

 tral feet form another character which is not easily overlooked. 



The Velcro specimens have large tufts of gonads and appear to be 

 adult individuals. 



3. Neothyone gibbosa, new species 

 Plate 21, Figs. 7-11; Plate 22, Figs. 1-8 



Thy one gibber Deichmann, 1938, p. 376, text figure 11. Nee Thyone 

 {Stolus gibber Selenka, 1867, p. 356, now Neothyone gibber ^ see 

 above ) . 



Diagnosis. — Medium-sized form superficially resembling Thyone 

 gibber in its external and internal anatomy. 



Spicules an insignificant layer of shallow knobbed baskets derived 

 from buttons, easily overlooked, and an inner layer of regular 4-holed 

 buttons strongly knobbed mostly with handle and some with a few spines 

 of varying size on the handle. Feet with large end plate, walls with nu- 

 merous heavy supporting tables, mostly with low spire composed of several 

 rods, occasionally more well-developed spire may be found ; especially in 

 the dorsal feet in older individuals a number are developed as smooth 

 plates often with one side expanded, with scalloped edge. Introvert with a 

 varying number of mostly larger tables with numerous holes in the oblong 

 disk and a low spinous spire. Tentacles with heavy perforated plates and 

 rods decreasing in size in the branches ; in many cases also rosettes. Color 

 in alcohol dirty gray or reddish, often darker mottled in the interambu- 

 lacra; tentacles rather darkly colored. 



Type. — Holotype, AHF no. Z3. 



