4. P.Silius, governed Bithynia and Pontus as propraetor in B. C. 51, at the same time as Cicero governed Cilicia as proconsul, Bibulus Syria, and Thermus Asia. Silius was a friend of Atticus (Cic. Att. 6.1.13, 7.1.8). Several of Cicero's letters are addressed to this Silius. He consulted Cicero on a legal point in B. C. 44, the explanation of which has exercised the ingenuity of modern jurists. (Cic. Fam. 7.21, ad Att. 15.23, 24; P. E. Huschke, De Causa Siliana, Rostochii, 1824, and also in his Breslau, 1830, vol. i.) This Silius was probably the father of P. Silius Nerva, consul in B. C. 20. [SILIUS NERVA.]