This is a box of .38 Smith & Wesson cartridges made in Palencia. Loaded experimentally with nickel plated Boxer primers.
10.15 gram (157 grains) roundnose solid lead bullet. Both knurled and plain bullets were used.
This round was named “.38 Short” to distinguish it from the .38 Special, which was named “.38 Long” at that time.
Reference: Molina-Orea 1992, page 821.