The original The Atlas of Mouse Development by Matt Kaufman (MK) included transverse and sagittal sections at multiple stages of development, but only two plates of coronal sections (stages E14.5 (plate 34) and E16.5 (plate 39)). When a revised version of the Atlas was suggested, a survey of users recommended that the series of coronal sections should be extended to include additional stages of development, particularly the brain at E11, E11.5, E12.5, E13.5, and E15.5. This chapter presents these new coronal sections, together with some new sections to extend the E14.5 images provided in the original Atlas. These sections include some original annotations from MK that are supplemented by more detailed brain annotations.