part of part of telencephalic ventricle hippocampal formation regional part of brain calcar avis of the lateral ventricle Morand spur calcar unguis avis neuronames:210 On the medial wall of the posterior cornu of the lateral ventricle is a longitudinal eminence, the calcar avis (hippocampus minor), which is an involution of the ventricular wall produced by the calcarine fissure. It is sometimes visible on ultrasonogram. BTO:0004691 minor hippocampus SCTID:369271006 FMA:83707 calcar avis calcarine spur UBERON:0035970 DHBA:12095 Wikipedia:Calcar_avis hippocampus minor CalA pes hippocampi minor Haller unguis ergot