Abstract We compute the S n S₍ -equivariant topological Euler characteristic of the Kontsevich moduli space M ̄ 1, n (P r, d) M₁, ₍ (P^r, d). Letting M ̄ 1, n nrt (P r, d) ⊂ M ̄ 1, n (P r, d) M₁, ₍^nrt (P^r, d) M₁, ₍ (P^r, d) denote the subspace of maps from curves without rational tails, we solve for the motive of M ̄ 1, n (P r, d) M₁, ₍ (P^r, d) in terms of M ̄ 1, n nrt (P r, d) M₁, ₍^nrt (P^r, d) and plethysm with a genus-zero contribution determined by Getzler and Pandharipande. Fixing a generic C ⋆ C^
Kannan et al. (Wed,) studied this question.