This category of data will be less accurate and less valid for generalisation than that surrounding the first noted appearance of a name. A number of toponyms were intermittent anyway and thus tracking down their final instance may be a matter of luck. In some cases names that had been generally abandoned might be continued by a few chartmakers, or even just one (see the note on Benincasa's successors below).

The totals of abandoned names are listed for each of the atlases or charts where they were last seen, in the same way as for the toponymic innovations. On this see the general table to The disappearance of 'Significant Names' from the 31 sections of coastline (tables) (a Microsoft Word document). This divides the continuous coastline between northern France and west Morocco into 31 sections, whose coverage can be seen on Table 4 of The addition of 'Significant Names' to the 31 sections of coastline (tables) (a Microsoft Word document). In addition, Table 3 on the 31 sections Disappearances sheet lists the number of last appearances by each chartmaker, and is sortable by period.

To give a more generalised picture, those 31 sections have then been grouped into seven regions [The disappearance of 'Significant Names' from the seven main regions (charts & tables) (a Microsoft Word document)]. These comprise: (1) the Atlantic coasts, (2) from southern Portugal round to southern Italy, (3) the Adriatic and Morea (Peloponnese), (4) the Aegean and Sea of Marmora, (5) the Black Sea, (6) the southern coast of Turkey and the eastern Mediterranean, and (7) North Africa. Since the number of names in the various sections and regions varies considerably, the totals are also expressed as percentages to provide meaningful comparison.

This second document, dealing with the seven regions, includes three graphs and a table - (1) comparing the totals of new and abandoned names over five periods up to 1600, (2) & (3) contrasting the abandonment of names in the seven regions and (4) a table showing the totals and percentages of abandoned names for those seven broad regions.

In all, 462 names were identified as having first formed part of the repeated component of portolan chart toponymy and then been removed before 1600. As a measure of chart dynamism, that represents just under half of the so-called 'Foundation Names': those found on the earliest works of Pietro Vesconte (1311-13). For the overall figures see Innovative Names (essay).

The first half of the 16th century saw the same kind of conservatism in discarding names as there was in introducing them, but the shedding of early names accelerated towards the end of the period considered here (up to 1600). Caraci had noted that for the Italian peninsula some 20-30% of the medieval names disappeared in the second half of the 16th century (1939, p.170 - via Astengo, 2007a, p.204b). My overall figure is considerably higher, around 60%: 280 out of 462.

However, the main reason for such a large total for the final half century of this analysis is the slavish adherence of Grazioso Benincasa's followers to his toponymy. This applies particularly to the individual who was presumably the last of the Anconitan chartmaking Freducci family, active up to 1556, as well as the Cretan chartmaker Georgio Sideri, who signed as Callapoda and worked, at times at least, in Venice between 1537 and 1565. For a century, the Freducci dynasty and Sideri kept alive the Benincasan flame, as set out in the toponymy of his earliest works (up to 1465). In a number of cases those names had been jettisoned by other chartmakers before or shortly after 1500. [See Table 1 in The disappearance of 'Significant Names' from the 31 sections of coastline (tables) (a Microsoft Word document) and in particular Note 3].

The portolan chart printed in Venice by Matteo Pagano in 1568 [see Nordenskiöld's Periplus Pl. XXVII] preserves a number of the Benincasa-Freducci-Sideri names. However, since this is an uncritical copy of a 1539 woodcut by Giovanni Andrea Vavassore the fact that it gives about 15 extra years' currency to some of those names (by then generally obsolete) did not seem to need specific mention.

The only other totals of discontinued names worth noting (40 in each case) can be found at either end of the time-scale: Vesconte (considering just those names abandoned after his two latest works) and Martines (mostly on the 1591 atlas). Other totals of toponymic last appearances that deserve mention are chalked up to two Venetian practitioners, Fiorino (1462) and Nicolai (1448, 1470).

Table 4 of The disappearance of 'Significant Names' from the seven main regions (charts & tables) (a Microsoft Word document) demonstrates that, of the seven broad geographical regions, the Atlantic coasts and those of the Adriatic and Morea saw the largest volume of toponymic disposal. At the other end of the scale and, at about one third of the total, the long stretch from the southern coast of Asia Minor round to Morocco was the most static.

What was the origin of these abandoned names? Unsurprisingly, a large proportion (219, i.e. 47%) were 'Foundation Names'. Sixty of the subsequent Vescontian innovations had disappeared by 1600 but some of those are not seen on the work of any later chartmaker and, in the strict sense of my definition of 'significant' name, should perhaps not have been included. Sixty-nine further names were discarded from those introduced later in the 14th century, 89 of those first seen in the first half of the 15th had disappeared by 1600, as had 25 (more than half) from the slender total added in the second half of the 15th century. The latest date on a recorded innovation that had been purged by 1600 was a name first seen in 1489 (No.1268 sesin). In other words all 110 names introduced during the 16th century can still be found on charts of the following century, despite the ruthless culling that characterises the last part of that period.

Overall, 243 of those names that had been added to the charts on or after 1313 had been removed from the charts by 1600. That represents more than half of all the 462 abandoned names. The pace of removal quickened markedly in the 1580s and the provisional finding, that many more disappeared in or close to the first decade of the 17th century, suggests that the period 1580-1610 was one of extensive weeding. The portolan chartmakers (or perhaps just the role models among them) were constantly assessing the relevance of their complement of place-names, removing those that no longer had navigational significance and replacing them with others that did. It seems likely that the same seafaring informants who urged the inclusion of new names also advised on those that should discarded.

Before any valid conclusions could be reached about the reason for the abandonment of a name, information needs to be gathered from local studies. A possible explanation might be the silting up of a port, leaving it inland and irrelevant. As is so often the case in portolan chart studies, where generalisations are always dangerous, our further, deeper understanding of this still startling group of documents may depend on a series of tightly focused studies of individual names.