[24]See Kret., Port., pp. 81-93; see also E. L. Stevenson, _Portolan Charts: Their Origin and Characteristics, with a Descriptive List of those Belonging to the Hispanic Society of America_, New York, 1911, p. 19, where it is suggested that the faulty orientation of the Mediterranean may be in part connected with the persistence since the time of Ptolemy of the practice of placing Constantinople on maps “too far to the north by at least two degrees.” APPENDIX DETAILED COMMENTS ON THE MAP Explanation The following commentary is divided into sections numbered with Roman numerals corresponding to the Roman numerals on the general key map (Fig. 4, at end of book). Each item is given an Arabic numeral which corresponds to the Arabic numerals on the detailed key maps (Figs. 5-10, at end of book). For each feature which bears a place name and for each longer legend on the Leardo map the transcription is given below in italic. Many of these transcriptions, particularly of names written on edifices (castles, churches, etc.), are mere guesses, owing to the obscurity of the original. Particular difficulty was encountered in distinguishing between the letters _a_, _e_, _o_, _c_, and _t_, and between _s_ and _f_. A clue to the reading of many names, however, was furnished by other maps contemporary with or earlier than that of Leardo. Illegible letters are indicated by dots; doubtful readings by (?); interpolated letters are enclosed in square brackets. Illeg. means “wholly illegible.” No data beside the transcriptions are given for such names as _f. tigris_, _corsicha_, _galizia_, etc., the meaning of which is obvious. In the case of the less familiar names, the forms in which they appear on certain other medieval maps are supplied. In general, if a name occurs on the Catalan Atlas of 1375 (CA), on the Catalan map in the Este Library at Modena (CE), or on the Ptolemaic maps (Ptol.), no attempt is made to indicate its occurrence elsewhere. Each doubtful identification with a medieval name is preceded by ?. For names along the coast of the Mediterranean, the Black Sea, and the Atlantic, references are given to the pages in Kretschmer’s _Die italienischen Portolane des Mittelalters_ (= Kret., Port.) where the variant spellings of these names as they are found in the more important portolans and portolan charts are listed and the places identified with modern localities. Identifications with modern localities are indicated by =, or =mod.; with well-known ancient localities by =anct. Suggested but doubtful identifications are preceded by =?, and names for which I have been unable to find or to suggest any identification with a modern locality are indicated by =? standing alone.