110 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL. 8 



Nec Thyone gibber Deichmann. 1938, p. 376, text figure 11 (Neothyone 



gibbosa, spec, nov., see below). 

 Thyone similis Lud%A-ig. 1887, p. 23, pi. 2, fig. 7. 



Diagnosis. — Medium-sized form, often with body strongly contracted 

 and the blunt oral and anal ends upward cur\-ed. Calcareous ring fairly 

 delicate with well-developed posterior prolongations on the radials; 

 interradials narrow. Single dorsal stone canal, usually several Polian 

 vesicles. 



Spicules large 4-holed buttons varying from regularly knobbed to 

 swollen; the latter are especially characteristic of the older individuals. 

 The 2 knobs in the center of the button are often united to a handle on 

 both sides of the button. The external layer of buttons has normally dis- 

 tinct teeth developed on the handle of the external side; sometimes ac- 

 cessor}- rods from the margin of the button connect with the spines. Feet 

 with large end plate and numerous stout supporting tables with several 

 rods in the spire and a var5ing number of teeth on the top. Introvert with 



I I M I I I I I I I 



Text fig. 5. Neothyone gibber (Selenka), juv., still in the "Pen- 

 tamera" stage. 



1-2. Buttons. 



3. Supporting table. 



4. Table from introvert. 



5. Plate from tentacle. 



6-7. Rosette and rod from tentacle. 

 Scale, Hoo ™ni. 



