190 



K. MITSUKUEI : STUDIES ON 



pedicels (10 — 34 in number on each side). Polian vesicle one, 

 not colored. Genital opening on a papilla on the median dorsal 

 line. Stone-canal opening by means of 5 — 8 pore-canals near the 

 genital opening. 



Calcareous deposits : With a hand-lens, one can recognize 

 in the fresh state numerous white spots scattered everywhere in 

 the perisome on the dorsal as well as the ventral surface ; these 

 are wheels. The large wheels have six or rarely five unequal 

 holes in the center, and nine or ten (rarely eight) spokes (textfig. 

 35a). The diameter measured 0.132 — 0.096 mm. in those near 



the anterior end of the dorsal surface, and 

 O.OGO — 0.075 mm. in those in the pedicels 

 and the ventral perisome. Besides these, there 

 are smaller wheels with four central holes 

 and twelve or thirteen spokes (/>), the diam- 

 eter measuring 0.032 — 0.04G mm. In the 

 pedicels, there are, besides these wheels, 

 supporting rods about 0.2 mm. long, which 

 are spiny near the ends and somewhat 

 bent (c). They are most crowded near the 

 ends of the pedicels. The pedicels have 

 also well-developed end-plates. In the 

 tentacles, bent or nearly straight irregular 

 calcareous rods are found near tlie tips of 

 the branches. 



Bcmarhs : — The specimens are mature 

 as the sexual organs were ripe at the time 

 of capture. The great peculiarity of this species is its small 

 size and its numerous lateral pedicels, which are more slender 

 and more numerous than the dorsal papillae. If emphasis be laid 



Textfig. 35. 



Zœlmogone seknkai : a — 

 Large wheel ; h — SmfiU 

 wheel ; c — Supporting rod of 

 pedicel. (x240). 



