1. Introduction Travis and Gonsalves (1969) and Carriker (1969) hypothesized that the accessory boring organ of such gastropods as Urosalpinx cinerea (Say) may secrete a protease, possibly a conchiolinase, during penetration of prey shell. They suggested that the enzyme initially may dissolve the non-mineralized organic matrix surrounding the calcareous units of shell, exposing the units to solution by acids, chelators, or both....