Abstract
The spermatophores of Coptophylla caroliniani and Aceria mississippiensis consist of a base which is glued to the substrate by an adhesive substance, a stalk, and an expanded head with a sperm packet resting on a central projection. The C. caroliniani spermatophore has a twisted stalk whereas the A. mississippiensis spermatophore has a straight stalk that is twisted near the junction of the head and stalk. A fan-shaped head is characteristic of a C. caroliniani spermatophore whereas A. mississippiensis has a shield-shaped head. The central projection which attaches the sperm packet to the head is oblong in C. caroliniani and cylindrical in A. mississippiensis.