In this last connection, I note that on 22 November your link gives a Japanese intelligence source as stating, "The naval defense area, patrolled against possible lightning attacks, extends in the north from Salina Cruz on the Tehuantepec Isthmus to Monepene (on ?) the Gulf of Fonseca. The southern limits extend to the air base on the Galapagos Islands." What air base? I didn't know the US had started to build the air base yet, but if the Japanese thought they had this would rather scupper the use of the Galapagos as a launch point for the attack)
I think this link will show that no air bases were constructed in the Galpagos Islands until after the attack on Pearl Harbor:
On 11 December 1941, Army Headquarters, Army Field Forces, advised Commanding General, Caribbean Defense Command, that Ecuador had made available to the United States the Galapagos Islands and the Ecuadoran Coast for “the establishment of such military bases as may be necessary.”5
 On 12 December 1941 the Comandant, 15th Naval District, issued orders directing that a temporary advance air base be established at Seymour Island of the Galapagos group.1
On 4 January 1942, the Commanding General, Caribbean Defense Command, directed that steps be initiated for the construction of auxiliary air bases in the Galapagos Islands.2
From May 1942 through the remainder of the year, there were many conferences and letters concerning proposed written agreements between the United States government and the Ecuadoran government for the use of the Galapagos Islands, but no formal written agreement was ever concluded.3
The first plane landed on the Galapagos air strip in early April 1942, only two months after the beginning of construction. The runway was used constantly from that date until its final completion, July 1943.1 Two important factors were ever present during the process of construction: shortage of water transportation to afford the needed supplies and equipment; furnishing the troops and construction forces with sufficient water. On 10 March 1942, Colonel (later Brigadier General) Young, then Panama District Engineer, stated: “The situation as regards the construction at base Beta2 is critical on account of the failure to provide water transportation.3 He reviewed General Andrews' original order that the Navy would furnish the shipping facilities and outlined the failure of that plan to afford enough materials. The Navy planned to handle the shipping by using the “Ferncliffe.” This ship arrived in the Canal Zone after some delay, loaded aboard all that
It's apparent from these links also that an air base was not constructed on Baltra Island until after the Pearl Harbor attack:
The map was producd in 1942 in response to the realization of the Galapagos' strategic importance for a war in the eastern Pacific a very real threat after the Japanese attacked Pearl Harbor in 1941. The U.S. set up a base on Baltra Island at the northeastern tip of Santa Cruz.
[b]During World War II Baltra was established as a US Air Force Base. Crews stationed at Baltra patrolled the eastern Pacific for enemy submarines and provided protection for the Panama Canal. After the war the facilities were given to the government of Ecuador. Today the island continues as an official Ecuadorian military base. The foundations and other remains of the US base can still be seen on the island.
My guess is that if the Japanese agent actually mentioned "air base on the Galapagos Islands" in his communique of 22 November 1941 he was referring to a proposed air base site that he may have caught wind of. It's amazing what a little internet research can turn up.
BTW Sid, weren't you the guy that totally derailed a fascinating thread about U-boat landings in southern Argentina circa July 1945 with this same kind of obtuse questioning of every single detail?