Gen I Thomas Linthicum Sr, (name written Linscombe in list) b. about 1640 in England or Wales, transported by Capt. Edward Selby to Maryland, prior to July 23, 1658...etc.
Note the name spelling when he was "signed in". I have seen a series of Linscombe's as part of the Munster Plantation of John Popham from the 1580s to 1641. Thomas later used the spelling Lincecombe when buying land in May 1676, and the Linthicum spelling on his death.
Should offer a word of caution about the Internet and a source like the International Geneaology Index and accuracy. Anyone can put anything on the net, and the IGI tries to put cautionary warnings on those IGI entries that are put there to gain relatives entry into a special status after death. For your information both Thomas and Jane are in IGI as if they were known to have been born in Wales, the phrase he used when coming to Maryland was that he was "a gentleman from Wales".
Several Welsh geneaologists and researcher into Welsh surnames have all told me the name isn't Welsh. Perhaps a dead end but Thomas was a Quaker when he came to America and George Fox preached in Wales in the 1650s.