while the details of the trade were finalized. Cadamosto spent nearly an entire month in an inland village, hosted by the prince Bisboror (Budomel's nephew), during which time he delighted in observing much about the local country and customs. His trade in Cayor completed, rather than return home with his human cargo, Cadamosto decided to cruise further down the coast, towards the Cape Vert peninsula. This was intended as a pure exploratory jaunt, "to discover new countries" beyond the Cape, more specifically the mysterious "kingdom called Gambra", where Prince Henry had heard (from earlier slave captives) that gold was found in abundance. Around Cape Vert, in June 1455, Cadamosto came across two Portuguese caravels, one of which was commanded by Antoniotto Usodimare, a Genoese captain in Prince Henry's service, the other by an unnamed squire of Henry's household. They agreed to join forces and proceeded south together. After a brief fishing stop on some unnamed islands (probably Îles des Madeleines), Cadamosto, Usodimare and the Portuguese squire sailed south, down the Petite Côte until they reached the Sine-Saloum delta, a stretch inhabited by the Sereri (Serer people). Cadamosto has nothing good to say about the Serer, characterizing them as savage idolaters "of great cruelty" (although we should note at this point his information is being drawn principally from Wolof interpreters). Cadamosto claims he was the one who named the Saloum River as the Rio di Barbacini, the name by which it would remain known on European maps thereafter. Cadamosto and Usodimare tried to put in there, but quickly decided against it when an interpreter they landed to make contact with the local Serer natives gathered on the beaches was killed on the spot. Pressing south, Cadamosto and Usodimare finally discovered the mouth of the Gambia River in late June or early July 1455. They set about sailing upriver, but their advance faced unremitting hostility from the Mandinka inhabitants upriver. Subjected to intense missile fire, they barely fended off a massed canoe attack that sought to trap and board them. According to Cadamosto's interpreters, the Mandinka believed the Portuguese were cannibals, that they had come to the region to buy black men to eat. Urged by their frightened crews (and probably desirous to keep his human cargo intact – he had been carrying a shipload of slaves since Cayor), Cadamosto decided to call off venturing further and backed out of the river.