You are correct. The Aridisol codes are in error. We are aware of the following errors in SOIL TAXONOMY 2nd Ed.
SOIL TAXONOMY 2nd Ed. 1999 - Errata:
Page 57 Photo 11 Change ""Umbrept"" in caption to ""Xerept""
Page 329-388 The first letter of the numbering sequence for all Aridisols should be changed from ""F"" to ""G"".
Page 614 column 1, IFGE. Pachic Udertic Haplustolls, item 1. Should be rewritten as: ""1. A mollic epipedon 50
cm or more thick with a texture finer than loamy fine sand; and""