2 1/4 x 3 9/16 in. CDV on cardstock mount (minor spotting and minor loss to upper left corner of print; soiling and edge/corner wear to mount). Snell's pictorial imprint to verso. The subject is attributed as an unidentified Zouave of Company A, Salem Zouaves (founded in 1805 as the "Salem Light Infantry"). He wears a trimmed jacket (likely navy blue twill with collar trimmed in red leather), trousers with stripe, and white gaiters with lace-up outer seams. Strangely, his kepi bears a large numeral "8" and a small numeral "3," which is not consistent with what Salem Zouaves were typically known to have worn on their headgear - brass letters "SZ" or "SLI." 

The pre-war Salem Zouaves (Militia) were part of the 8th Infantry Regiment of Essex County. With the war they became Company I of the 8th Massachusetts Volunteer Militia (MVM). The 8th MVM was a three-month regiment that mustered out in August 1861 without having seen any active campaigning. The entirety of the Civil War uniform issued in June 1861 was described as made of "navy blue twill with collar trimmed in red leather" and jacket trimmed in red tape. Navy blue trousers with red stripe, and white gaiters with lace-up outer seams. The kepi had a red crown over a blue lower body.  

This image is published in American Civil War Zouaves (p. 25) and credited to Mike McAfee.