Samuel Ball Platner, Thomas Ashby, A Topographical Dictionary of Ancient Rome

PORTICUS ARGONAUTARUM

built by Agrippa in 25 B.C. (Cass. Dio liii. 27), probably near (or, as Hilsen thinks, enclosing) the temple of HADRIAN (q.v.). It derived its name from the paintings on its walls of the adventures of the Argonauts, and seems to have been also called the porticus Agrippiana (Schol. Iuv. vi. 54). Cassius Dio (loc. cit.) calls it στοὰ τοῦ ποσειδῶνος, and elsewhere (lxvi. 24) speaks of a Ποσειδώνιον, which is probably the same building. It is sometimes identified with the BASILICA NEPTUNI (q.v.), although both names occur in the Curiosum in Reg. IX. It is possible that the porticus may have belonged to a temple of Neptune, although Ποσειδώνιον does not necessarily refer to a temple, and there is no other evidence for the existence of one in this region. This porticus was one of the most frequented in Rome (Mart. ii. 14. 6; iii. 20. 11; xi. I. 12; HJ 574; Lucas, Zur Geschichte der Neptunsbasilica in Rom, Berlin 1904; OJ 1912, 132 ff.).