This paper proposes a shared, distributed, asymmetrical model for the bilingual mental lexicon. To test the sharing of conceptual relations across translation equivalents, Experiment 1 used the classical priming paradigm with specific methodological innovations, trying to satisfy various constraints that had not been addressed in previous studies. The results suggest shared storage for the conceptual representations of the bilingual's two vocabularies and asymmetrical links between concepts and lexical names in the two languages. Experiment 2 examined the details of meaning separation by eliciting semantic closeness rankings for conceptual relations that are equivalent across language translations and those that are not. The results indicate that bilinguals tend to integrate conceptual differences between translation equivalents, but that they also display a "separatist" tendency to maintain the L1 conceptual system in the representation of L1 words and to adopt the L2 conceptual system in the representation of L2 words.