“About 1915 [following English Caslon Oldstyle No. 37] Monotype cut yet another version of Caslon Old Style—No. 337, designated ‘MacKellar Caslon’ in some early literature because it is closer to the original typeface associated with that foundry. Display sizes are virtually an exact copy of No. 471. Composition sizes are well adapted, though necessarily modified to fit the standard arrangement; they are made with short descenders on standard alignment, but were the first Monotype typeface with alternate long descenders. Oddly, all three Monotype Caslons—37, 137, and 337—are the same set width—letter for letter—in all keyboard sizes made, which means that any given character is precisely the same width from one typeface to another in any composition size. In addition, 12-point No. 337, which with long descenders must be cast on 13- or 14-point body, is essentiallythe same size and width as 14-point of the same face. Sizes of this typeface above 36-point were later copied from Stephenson Blake's Caslon Old Face and called Caslon Old Style No. 437, as previously noted.” [McGrew 1993]

Digitizations by Gerald Giampa in roman and italic (Lanston Type Company, by 1994, used for sample; later revised as LTC Caslon) and URW (italic only, with swash caps, based on a display size).