Guillaume Bigourdan found IC 3256 = Big. 291 on 23 Apr 1895. His position matches UGC 7466, which is often taken as NGC 4342. But see that number for the story.

400/500mm - 17.5" (3/28/87): moderately bright, very small, elongated NNW-SSE, bright core, stellar nucleus. NGC 4342 = IC 3256 has the highest surface brightness of the members in the NGC 4343 group. NGC 4343 is 6.0' S, NGC 4341 = IC 3260 4.8' NE, IC 3267 6.6' E, IC 3259 8.3' NNE. See notes on the identification.

Notes by Steve Gottlieb