Cartographer
145. A map of 1 March 1827 published in London by James Wyld, Geographer to His Majesty and the Duke of York, is entitled "Mexico and Guatemala, showing the Position of the Mines". It carries the words "British Settlements" across the area north of the River Sibun. The area to the south of that river and south-east of the mountain range, extending southwards to the Gulf of Dulce carries the name "Vera Paz". But there is no indication of any Guatemalan town or settlement in that area other than the town of "Cahaban", well to the south of the River Gorda. This town appears on later Guatemalan maps as "Cajabon", much further to the west and well inside what is indisputably Guatemalan territory. A later edition of the same map, published in 1873, clearly shows the 1859 boundaries and inserts the name Sarstoon against the river of that name, which was unnamed in the earlier edition. Even then, however, there is no indication of any significant named Guatemalan location east of Cahaban and certainly none east of the 1859 border.
Source: http://www.belize-guatemala.gov.bz/library/legal_opinion/part%20one_5b2.html
It is possible that this James Wyld was a renowned English cartographer. However according to http://www.antiquemaps.co.uk/book/chapter15.html James' father was also a James Wyld. Here's what I found:
JAMES WYLD (the Elder) 1790-1836
JAMES WYLD (the Younger) 1812-87
The Wylds, father and son, were highly successful map publishers in London for well over half a century. The Elder succeeded to William Faden's business, taking over his stock in 1823, and from then onwards he, and later his son, issued a large number of atlases and maps, including re-issues of Faden's maps - all noted for their excellence. In turn they both held the appointment of Geographer Royal, and the Elder was also a founder member of the Royal Geographical Society.
c. 1819-25 A General Atlas
1820 Settlements in New South Wales
c. 1824 Map of North America (6 sheets) Revised issues to c. 1856
1837 Map of Australia compiled from nautical surveys
1840 Chart of New Zealand
c. 1838-41 (the Younger) A New General Atlas (large folio)
1842 (the Younger) Atlas of Modern Geography
1849 (the Younger) Popular Atlas of the World