Understanding how neural circuits are organized is crucial to understanding how animal behavior is generated. Previous volume electron microscopy (vEM) studies in model organisms such as D. melanogaster and C. elegans have provided structural maps for understanding how information is transmitted throughout the nervous system. Here, we applied volume electron microscopy (vEM) to reconstruct neurons and determine synaptic connectivity within the rhinophore ganglion (rhg) of the nudibranch mollusc Berghia stephanieae. The rhg sits at the base of the rhinophores, an olfactory organ, and is presumptively involved in olfactory processing. From our volume EM dataset, we identified a neuropil region containing two neuronal cell types: projection neurons with axons projecting out of the ganglion and afferent neurons originating from the rhinophore nerves. The projection neurons were found to have overlapping dendrites that were contacted by the afferent neurons. Synaptic connections between the projection neurons and the afferents were identified and characterized into four types: monadic, dyadic, polyadic, and convergent. A convergent motif between the projection neurons and afferents was observed. Notably, axo-axonic synapses between afferent neurons was also identified. Convergent input onto projection neurons is a characteristic feature of olfactory glomeruli seen in insects and vertebrates. The presence of olfactory glomeruli in molluscs has been controversial. If this glomerular motif is repeated within the rhg, it would suggest that olfactory glomerular organization evolved independently in molluscs, arthropods, and vertebrates.