_Sigma_ retains its angular shape ([Symbol] or Σ) only on inscriptions, as the Rosetta, and that long after the square shapes of _omicron_ and _theta_ were discarded. The uncial or semicircular form, however, arose early, and to this letter must be applied all that was said of _epsilon_ as regards terminal points (a knob at the lower extremity occurs even in Cod. א, e.g. Acts ii. 31), and its cramped shape in later ages. _Tau_ in its oldest form consists of two straight lines of like thickness, the horizontal being bisected by the lower and vertical one. As early as in Cod. Sinaiticus the horizontal line is made thin, and strengthened on the left side _only_ by a point or small knob (Nos. 3, 11): thus we find it in Cod. Laud. of the Acts sometimes. In Cod. Alex. _both_ ends are slightly pointed, in Codd. Ephraemi, Rossanensis, and others much more. In Cod. Bezae the horizontal is curved and flourished; in the late uncials the vertical is very thick, the horizontal fine, and the ends formed into heavy triangles (e.g. No. 16). _Upsilon_ on the Rosetta stone and Herculanean rolls is like our Υ, all the strokes being of equal thickness and not running below the line: nor do they in Hyperides or in Codd. XZ and Augiensis, which have the upper lines neatly curved (Nos. 6, 9, 18, 38). The right limb of many of the rest is sometimes, but not always curved; the vertical line in Codd. Vatican. and Sinaiticus drops slightly below the line; in Codd. A, Ephraemi, Cotton Genesis, Cureton’s Homer, Laud. of the Acts and Rossanensis somewhat more; in others (as Codd. Bezae NR) considerably. In the subscription to St. Matthew’s Gospel, which may be by a somewhat later hand, a horizontal line crosses the vertical a little below the curved lines in Cod. Rossanensis. In later uncials (Nos. 7, 36) it becomes a long or awkward Y, or even degenerates into a long V (No. 16); or, in copies written by Latin scribes, into Y reversed. We have described under _iota_ the custom of placing dots, &c. over _upsilon_. But in Tischendorf’s Leipzig II. (fragments from Numbers to Judges of the seventh or eighth century) _upsilon_ receives two dots, _iota_ only one. Once in Cod. Z (Matt. xxi. 5) and oftener in its Isaiah a convex semicircle, like a circumflex, stands over _upsilon_.