This image comes from a recent post about Mentana on Gary Byrne’s impressive Italian Wars of Independence blog. I hope that Gary will not mind my posting it again here.
The picture is, I think, what the French call an Image d’Epinal. (One of our French experts, like Paco will no doubt correct me if I am wrong.) Although the image is small and rather primitive, I think it gives a good idea of the appearance of French line infantry at Mentana. The baggy chasseur style trousers, the absence of the greatcoat and the shako being worn rather than the kepi together give these men a distinct profile significantly different from the more familiar styles of 1859 and 1870.
Note also the Garibaldian and Papal Zouave casualties.