Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Augurs - Pontifices
Under the Roman constitution and that of the Latin communities in general there were originally but two such colleges; that of the augurs and that of the Pontifices.(11)
11. The clearest evidence of this is the fact, that in the communities organized on the Latin scheme augurs and Pontifices occur everywhere (e. g. Cic. de Lege Agr. ii. 35, 96, and numerous inscriptions), as does likewise the -pater patratus- of the Fetiales in Laurentum (Orelli, 2276), but the other colleges do not. The former, therefore, stand on the same footing with the constitution of ten curies and the Flamines, Salii, and Luperci, as very ancient heirlooms of the Latin stock; whereas the Duoviri -sacris faciundis-, and the other colleges, like the thirty curies and the Servian tribes and centuries, originated in, and remained therefore confined to, Rome.
But in the case of the second college--the pontifices--the influence of Rome probably led to the introduction of that name into the general Latin scheme instead of some earlier--perhaps more than one--designation; or--a hypothesis which philologically has much in its favour-- -pons- originally signified not "bridge," but "way" generally, and -pontifex- therefore meant "constructor of ways."
The statements regarding the original number of the augurs in particular vary. The view that it was necessary for the number to be an odd one is refuted by Cicero (de Lege Agr. ii. 35, 96); and Livy (x. 6) does not say so, but only states that the number of Roman augurs had to be divisible by three, and so must have had an odd number as its basis.
According to Livy (l. c.) the number was six down to the Ogulnian law, and the same is virtually affirmed by Cicero (de Rep. ii. 9, 14) when he represents Romulus as instituting four, and Numa two, augural stalls. On the number of the pontifices comp. Staatsrecht, ii. 20.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/1-12-religion.asp?pg=17