This is an EPENCO blue marble tiny fountain pen c. late 1930s, possibly a part of the EPENCO Elfin line of midget pens and pencils. This 4 3/16 inch long pen is unmarked except for the gold plated stainless steel nib stamped EPENCO N.Y. The gold plated clip follows the design of other EPENCO models, though without the PATD marking at the top. The Elfin line is shown in the Eagle Pencil Company 1937 catalog and came in fountain pens, pencils and pen-pencil combinations. Pen and pencil sets sold for 50 cents packaged in a paperboard box and pen-pencil combinations sold for 25 cents off of counter cards. Both came in a variety of solid and marbled celluloid pyralin colors, not all documented in the catalog. Eagle registered the EPENCO trademark on October 17, 1911.