They are normally called "butterfly plasters". They are roughly the shape of a butterfly. Google will find you images.
PS. Cross-posted with Rover. Steri-Strip, a trade-marked product, is not a butterfly plaster. The Wikipedia article is also wrong. Closure with Steri-Strips is not known generically as 'butterfly stitches' for obvious reasons - the closure looks nothing like a butterfly - and the example in the picture should be a cause for shame to whoever applied the strips. I accept that there are several websites using the term 'butterfly stitch' for Steri-Strips, but they also call Steri-Strips 'Steristrips' or even 'steristrips'.