Watch List notes:

ARABIA, Southern. Saba'. Late 4th–mid 2nd centuries BC. AR nṣf – Unit (15mm, 5.21 g, 6h). Imitating Athens. Helmeted head of Athena right; N (in retrograde South Arabian; mark of value) on cheek / Owl standing right, head facing; olive spray and crescent to left; all within incuse square. Van Alfen, Studies SIIA, 11c (dies O7/R7; this coin); CAF 1.1i; Huth 165-9; HGC 10, 720. Lightly toned, minor deposit on obverse. Good VF.

From the William H. Birkinshaw Collection. Ex Classical Numismatic Group 53 (15 March 2000), lot 682.