Cr 408/1, 67 BC
I bought this coin on line: Asta Numismatica 37E by Artemide Aste. I was interested in some cast bronze pieces, and won one of them that I will post later. I like Roman Republican coins and was only partially watching the auction when this coin appeared on the screen. I am a sucker for cast bronze pieces. I especially like plumb bobs, see my post on March 1, 2015. The symbol looked a lot like a Roman level, see pic below thanks to Plumb Bob Wolf (http://www.plumbbob.de/). I did not have much time to bid on the coin, so I passed on discretion and made a couple of bids. The other guy (I suppose it could have been a gal) stopped bidding and I won!!! I was not sure of the symbol, but it is a bit like the level. Charles Hersh wrote an excellent article on this coin series: Coinage of C. Calburnius Piso L. F. Frugi, in Numismatic Chronicles 1976. In that article he identifies the symbol as a pendulum.
I modified the seller's description and the one by Hersh -
Roman Republican Denarius, 67 BC, C. Calpurnius L.f. Frugi. AR.
Obv. Head of Apollo right, hair bound with fillet (see info below on fillet); behind, anchor (per vendor) or pendelum (Hersh) or level (Gene).
Rev. Horseman galloping right, holding palm branch; below, C PISO L F FRV/
uncertain symbol silphium seed.
BMCRR – Rome 3654 to 3815
RSC – Calpurnia 24 - 29
Cf. Banti 268/4.
My example of a bronze weight that could have been used on a Roman level.
The one that is probably not right, but looks right is:
The vet web site http://www.practicalpetvet.com/2012/01/ thinks a Taenia is a tape worm.