55 



i2. — Rays not infundibuliform (19). 



13.— A circlet 1 



14. — No circlet (17). 



15. — Stems longer than funnels. C. h m, Williamson. 



16. — Stems half length of funnels. C. Pjitzcri* A. S. 



17.— Inter-Radials distinctly punctate. C. Challcngerensis, Deby. 



18. — Inter-Radials nut punctate. C. latus,\ Shadb. 



19. — Rays reduced to short marginal apiculi or points, with ends 

 pointed centrally towards the area (21). 



20. — R. not reduced to small points (25). 



21. — A circlet. C. obsuletus, Cleve. 



22. — No circlet (23). 



23. — Rays very short, bifid at internal apex. Inter-Radials each 



with two marginal beads. C. diiitatus, Deby. 



24. — Rays longer, not bifid, ending very acutely. Inter-Radials 



with three or four marginal beads. C. ancepSy Castr. 



25. — Margin of valve double formed by two concentric rows of 



large beads, separated by a narrow, concentric, smooth 

 space. ('. bicinctus& Castr. 



26.— Margin not formed by a double row of beads, separated by 

 a blank circle (27 ). 



27. — Inter-Radials, with three longitudinal rows of fine puncta. 



C. pidcJullus,% Leud. 



* This seems to be a var. of C. horologium. 



•f- I unite under this name C. centralis^ Grev., C. coniigttu . A. S., and 

 C. ambiguuSy Grev. 



J Seems very local and proper to the inland sea of fapan. 



s' Under sufficient high power the area ol ' , finely punctate. 



