<p>A stone wellhead set up by one L. Scribonius Libo, either the tribune of the <i>plebs</i> of 149 B.C. (Coarelli 167) or the father of the L. Scribonius Libo who held the consulship in 34 B.C. (Frier), to mark a spot in the *Forum struck by lightning (Festus 448-50). The precise location of the wellhead, referred to both as the ‘puteal Libonis’ (Hor., <i>Ep.</i> 1.19.8: <i>... putealque Libonis</i>) and ‘puteal Scribonianum’ (<i>RRC</i> 416/1a-c, 417/1a-b: PVTEAL SCRIB.; cf. Festus 448), is unclear, since ancient sources locate it near ‘the <i>atria</i>’ (Festus, <i>loc. cit.</i>), ‘the <i>ianus</i>’ (Ov., <i>Rem. am</i>. 561), the *Fornix Fabianus (Porph., <i>Hor. Epist</i>. 1.19.8), and inside the <i>porticus Iulia</i> (schol. <i>ad Pers</i>. 4.49; s.v. *Divus Iulius, Aedes). Though Richardson associates it with the circular structure preserved in the <i>exedra</i> of the platform of the Temple of Divus Julius, recent opinion, following the suggestion of van Deman, favors a location inside the *Porticus Gai et Luci (Coarelli, Chioffi). On this reconstruction, the <i>atria</i> mentioned by Festus will refer not to the Atrium Regium and *Atrium Vestae, but rather to the *Atria Licinia; and the Porticus of Gaius and Lucius has to be identified with the <i>porticus Iulia</i> (cf. Coarelli 173-75). In the absence of secure archaeological evidence, however, this reconstruction cannot be regarded as definitive.</p>