It has long been recognized that the letters n and z, whose initial and medial forms had already fallen together by the date of the ‘Ancient letters’, remained distinct in final position, -n being provided with a long horizontal or vertical tail. At a slightly later period in the history of the Sogdian script two more pairs of letters—still distinguished in all positions in the ‘Ancient letters’— fell together: ‘ain with r,1 and x (ḥīth) with γ (gimel). The rare letter ‘ain does not occur in final position; but both x and γ are comparatively common in all positions. It is therefore remarkable that it should never have been noticed that final x and y are regularly distinguished in exactly the same way as -n and -z. The distinction is clearest in the Buddhist manuscripts,2 in which final x has a long horizontal or vertical tail: — (= ‘horizontal -x’) or L (= ‘vertical -x’), while final γ has only a rudimentary tail pointing down-wards. There is some variation in the distribution of the two forms of -x. In some manuscripts, e.g. Vim. and P 2, both are used interchangeably. In most ‘horizontal -x’ is preferred: it is the only form found in VJ, SCE, Dhu., P 5, and P 6, while in Dhy. and P 3 ‘vertical -x’ is also occasionally employed