1. A. Bohr andB. R. Mottelson:Dan. Mat. Fys. Medd.,27, no. 16 (1953).
2. A. Bohr:Rotational States of Atomic Nuclei (Copenhagen, 1954).
3. F. Villars: Private communication. Dr.Villars has independently treated the same problem discussed in this paper by essentially the same methods. The authors are indebted to Dr.Villars for sending them a copy of his manuscript and for several interesting comments.
4. The writers are indebted to Prof.G. Racah for directing their attention to these pathological cases.
5. E. Wigner:Gruppentheorie und ihre Anwendung auf die Quantenmechanik der Atomspektren (Braunschweig, 1931), p. 228.