This formation has been so heavily bombarded by subsequent impacts that it is nearly unrecognizable as a crater. Only the western and southwestern parts of the rim remains intact, the remainder having been obliterated by small craters. These craters also occupy parts of the northern and southern floor. Only a section in the northeast and near the intact western rim remain unmarked. This is perhaps the most defaced crater formation on the Moon that possesses an eponym.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Riccius.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID122125855.