On the form of potential spherical classes in $H_*Q_0S^0$

This note is about spherical classes in $H_*Q_0S^0$. A conjecture, due to Ed. Curtis, predicts that only Hopf invariant one and Kervaire invariant one elements will give rise to spherical classes in $H_*Q_0S^0$. Yet, there has been no proof of this conjecture around. Assuming that this conjecture fails, there must exist some other spherical classes in $H_*Q_0S^0$. This note determines the form of these potential spherical classes, and sets the target for someone who wishes to prove the conjecture, in the sense that correctness of the Curtis conjecture will be the same as failure of any classes predicted in this paper being spherical.