This is one of the short versions of the Spanish 1893 "Short" Mauser Knife Bayonet; this one has the "humps" removed from the back-side of the handle. There are about four distinct variants of this bayonet: smooth-wood grips with screws, "hump removed" (shown); smooth-wood grips with rivets, "hump removed"; smooth-wood grips with screws, with "hump"; smooth-wood grips, rivets, with "hump" (see image below). Most of these bayonets were manufactured at - and stamped - "Artilleria F-Nacionale Toledo" in one of about three different configurations, (I will show those at some other time). Some of these bayonets were actually made in Germany - and so marked - so they are almost identical to the German 1871/84 Mauser Bayonet.
The hilt construction is steel, with steel "bird's head" pommel, steel crossguard with muzzle-ring, and - as mentioned before - smooth wood grips.
The blade is single-edged, single-fullered (both sides) with manufacturer's stamp on one side of the ricasso, serial number on the opposite.
Scabbard is of "blued" steel throat and drag, mounted on black leather; tear-drop frog stud on the throat, with ball finial on the drag.

I should mention that there is a long bayonet was for use on the Spanish Mauser "Short" Infantry Rifle, although the bayonet is referred to as the Spanish Model 1913 "Long" Mauser Bayonet (aka 1893/13) . Also - as mentioned before - the German 1871/84 Mauser Bayonet is almost identical to this bayonet; the main differences being the muzzle ring is larger on the German version and sits up off the blade back-edge further (see image below).

According to "Janzen's Notebook," this bayonet was also used by Portugal.