Arnold Schwassmann found IC 3320 = Sn. 155 on 6 Sep 1900 using a plate taken with the 6" astrograph at the Königstuhl Observatory in Heidelberg. His position matches NGC 4390. Apparently he was unaware of the NGC identification (a number of his objects have NGC designations) and Dreyer catalogued it again as IC 3320. IC 3319 may be another designation from Schwassmann on a different plate, though the declination is off by 4'.

400/500mm - 17.5" (4/20/87): fairly faint, fairly small, slightly elongated E-W, diffuse, even or almost even surface brightness. Located 26' NNE of NGC 4380.

Notes by Steve Gottlieb