I believe the above map is a good example of the confusion that existed in Japan in the 1800s in regard to the locations of the islands of Takeshima (竹島) and Matsushima (松島). The Japanese had traditionally used the name "Takeshima" to refer to the Korean island of Ulleungdo and the name "Matsushima" to refer to Liancourt Rocks, but by sometime in the 1800s, Matsushima was also being used to refer to Ulleungdo. In 1882, for example, a Japanese marker dated 1869 was found on Ulleungdo that proclaimed the island to be the Japanese island of Matsushima.
A variety of factors most likely caused the name confusion mentioned above, but inaccurate Western maps and a Japanese travel ban to Ulleungdo (Takeshima) were probably the main causes. However, another factor contributing to the confusion may have been that some Koreans, at least, also referred to Ulleungdo as Matsushima (松島), which is pronounced as "Songdo" in Korean. Here is an excerpt from a 1793 Korean document:
臣按本曹謄錄蔚陵外島其名松島卽古于山國也The Japanese mapmaker seemed to have known that Takeshima was farther from Japan than Matsushima, but the fact that the two islands were drawn with similar shapes suggests there was still name confusion.
The attendant said that according to the Yejo record, "Songdo" was another
name for Ulleungdo and its surrounding islands, which was the old kingdom of